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 Post subject: 450 Carburetor Pictorial
PostPosted: Thu Mar 13, 2008 9:13 pm 
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City: Woodsboro
I'll start with a moment of background... I have a Rebel 450 that I bought in September. And ever since I got it there's been a slight problem with the carburetors. It has idled fine but always started sputtering when I started to roll on the throttle. It's a real problem! I can correct it by using the choke a little, but only after I get

moving. When I come to a stop I have to quickly shut the choke off. When I start moving again I have to turn it back on just a little until I get moving.

I have taken the carbs apart twice already, cleaned, scrubbed, polished, you name it, I've done it... But, still the problem has remained. What a Total Pain in the Monkey Butt!!!

So, today we were promised 60's outside with clear skies. At lunch time I told my boss I'm heading home as I had "Stuff I need to do". I quickly started pulling the carbs off again. After getting them off I decided I would photograph everything for those who were curious about what the 450 carbs looked like on the inside! I'll also give some descriptions of how various parts work and what things do.

Oh, and the short end of the story is Yes! I have it Fixed!!! It Kicks @SS!

I'm going to start from a disassembled carb and work back to installing it back on the bike.


Here's a picture showing THE problem.
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What you are looking at is the fast jet needle. I removed them from the vacuum pistons when I was figuring out what the problem was. As you can see the one on the left is sitting higher than the one on the right. The brass item on the right side on the bottom is the jet. The needle is supposed to come all the way down and close off the hole in the bottom of the jet until the engine revs fast enough to create a strong vacuum which draws the piston up and thus moves the needle up letting in lots of fuel. On the left side on the bottom you can see that I have the jet removed and the needle is just barely sticking out the bottom. At this level it will never move down and close off the fuel entering the jet.

Here's a good close-up showing the needle and the guide at the bottom of the carb throttle body.
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The guide can be pushed out the bottom of the carb.

So, here's the whole stup-up. Starting on the left and going right...
Vacuum Piston, Needle, Guide, needle jet holder, and the jet.
Image
Note that the Vacuum piston, needle and guide are all discontinued!
As the needle moves upwards it reveals more and more holes in the jet holder. There's a total 12 holes in this.

When you screw in the needle jet holder it actually mates tightly with the needle guide.
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Here's what it looks like if you have the jet holder mated correctly to the guide.
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And here's what it looks like if you forget to install the guide! I didn't tighten it down and this photo was just for use as an example.
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There was a burr on the inside of the top of the guide which was causing my problem! I used, by hand, a diamond coated dremel grinder to remove the burr. I'm guessing that the previous owner had removed the guide and used some metal tool to punch it out of the carb. In doing so they caused the burr. Some light movements of the tool finally got the burr removed. Also, it looked like there was additional corrosion at the bottom of the guide that needed cleaning too. After working it around and cleaning it throughly the needle finally moved freely in and out of the guide. I polished the needle afterwards as it was a little scratched up from the burr and me trying to get it to move freely.

OK, what next? How about assembly of the vacuum piston.
Inserting the needle into the top of the piston.
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Here is the nut that goes inside the piston that holds the needle in place. Every time I tried putting it in right side up it turned over. Finally, I put it in upside down and it flipped right side up!
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A slight push and a small turn locks it in place.
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When you insert it into the carburetor you DO NOT want the rubber in this way.
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You need to push the rubber up by sticking your hand into the throttle body and push up on the piston. The reason is that if you don't do this you stand a very good chance of causing the rubber to wrinkle when you add the cover.

That would be BAD! So, never take the cover off while the carbs are on the bike as you will not be able to put your hand in the throttle body to hold the piston up!

Here I am inserting the spring. Next step is to put your hand in, hold the piston up and then add the cover. It's lots of fun when you only have 2 hands and you're hold the cover on while it's being pushed up by the spring and the other hand is holding the piston up and you're trying to screw the cover on!
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Notice that at the top right of the rubber there is a tab. This has to go in the indent in the corner of the top of the carb. Also, the cover has a mark in one corner. This goes over the tab of rubber.
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When you add the covers, be sure that you put the choke cable bracket to the correct side.
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OK, on to new things. Here's the parts of the bottom of the carb. This is the fuel bowl area. Here's what you're looking at starting from the top and moving downwards. In the top right is the dark brown fuel inlet. I think this is called the banjo. Don't know why because I play a banjo and it looks nothing like this! Fuel flows both left and right and enters the fuel bowl through the brass item directly in the the top center of the fuel bowl. There is a rubber tipped float valve that goes inside this brass piece. Below it is the hole for the Needle Jet Holder. Third hole from the top is the hole where the slow jet gets inserted. I'm not sure what the last hole is used for. I belive it's a fuel return and has something to do with the air cut-off circuit. At the bottom right inside the fuel bowl you can see another dark hole. This is for overflow. It goes to the rubber hose tached to the side of the carb and drains out under the air cleaner.
Oh, and the HUGE black knob is the idle set screw!
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Add the needle guide first.
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This is the Bottom.
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So, be sure to insert this end into the hole!
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Then, add the needle jet holder. And screw the fast jet into the holder. It's this fast jet that you change when you are "Jetting" your carbs.
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Now, add the slow jet.
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The float assembly consists of three pieces. The non-adjustable float, the float valve and the pin. Although it's listed as a non-adjustable float because it's made from plastic, one of mine was adjusted and shimmed with a piece of plastic. I measured it's clearance and determined that it didn't need the shim and removed it. The purpose of the float and valve is to prevent too much fuel from entering the bowl. Without it the fuel would continously flow and thus flood out the carb. The float is also responsible for keeping a proper level of fuel in the bowl. Too low and the jets have nothing to suck up, too high and the jets flood. That's why there's a critical setting for the float. And if your float is not in spec you can flood or starve your carbs for fuel.

Here's the float valve attached to the float being inserted into the fuel bowl inlet.
Image

Here's the bottom of one of the fuel bowls. This one has the accelerator pump attached to it. Fuel enters the pump from the tiny hole at the top left of the bowl. When the pump is pressed a small amount of fuel is pushed up through the hole in the center of the black o-ring gasket. That, in turn, enters the rear of the carb next to the air box. So, every time you rev just a little you get a squirt of gas. The more you rev the more you squirt.

Keep it up to just waste gas!

Also, be sure to clean the bottom of this bowl. The first time I took the carbs apart the bottom of mine were filled with fine rust. There was so much that the drain was completely clogged.
Image

While you're at it, remove the drain plug and totally clean it.
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You can see in this photo that mine had started to corrode.
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I replaced the philip screws with hex screws. It really makes it easy to remove the bowls while the carbs are still on the bike. Now that I have it working correctly it really doesn't matter. But, but having this I can quickly get the bowls off, pull the jets and reassemble.
Image

OK onto the Idle Set Screw and its assembly. The screw when it's originally inserted and adjusted has a cap that's glued on top of the screw. This cap has a tab that prevents the screw from turning past the bracket that holds the carbs together. In order to remove the screw you have to either break off the tabs on the cap or remove the bracket. Don't remove the bracket! It's already aligned for your bike. File, grind or use huge nippers (as was done on mine) to remove the tabs. If you use the nippers be sure you don't bend the screw as you fight to cut the tabs off.
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Note that it's best to hold the carb up in the correct orientation while inserting the screw. This will prevent the rubber o-ring from moving and getting out of alignment. Remember, when you screw this puppy in, just screw it in until it seats. The moment you feel resistance, STOP. From that poing you back it out to the recomended setting. Not sure but for the '86 450 I believe it's something like 2 1/2 turns. That's what I did. I'm going on the assumption that if the tabs were still there that they would be set so that they rub up against the carb mounting bracket. Since I don't have a tach yet I'm not sure at what rpm I'm idling at. With using the tabs as a guide my bike is idling nicely. After I get a tach I'll do the idle drop to set them correctly. But, I won't be surprised if they are really close already.
Image

A little about the slow jet and idle jet.
Here you see several holes on the bottom of the throttle body. The one in the middle on the bottom is the idle.

When the throttle plate is closed this is where the carb gets its fuel. In the middle of the photo you see 4 additional holes. These are the slow jets. As the throttle plate starts to open more and more of these holes start feeding fuel into the carb. They are there to keep the carb going until there is enough vacuum created to activate the piston thus letting in more fuel through the fast jet.

Also, in this pic you see another hole on the right side. This is the choke, more correctly called the fuel enricher. It feeds off the slow jet and provides lots more fuel. Keep your choke on and you're just dumping fuel into the carb!
Image


Here you can see what it looks like when the throttle plate is closed. Note that the first hole in the set of 4 is directly under the throttle plate. When you're "eyeball" syncing your carbs, both throttle plates should look about the same. That's a good place to start. Get a manometer if you want better syncing. (I got one for $30 off eBay!)
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Adding the Fuel Line. You can see the banjo just behind the fuel line. Notice my tiny fuel filter?
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Here's my vacuum lines that activate the air-cutoff. It attaches to each carb and the right cylinder vacuum nipple. The air-cutoff shuts off fuel when you release the throttle quickly. That causes a vacuum drop which causes a spring loaded spring to shut off the fuel. (not an exact description but good enough)
Image

Here you can see the vacuum pistons. At the bottom of the throttle body you can see the brass pipe which is where the accelerator pump injects fuel into the carb. The ovel hole at the top of the throttle body is where in-rushing air causes the piston to move up. The more air that enters the carb the more pressure forces the piston up. If you just blow into this hole you can see the piston rise. Remember, it's this that fuels the fast jet.
Image


Now, onto installation!
After removing the carb 3 times I've come to the conclusion that taking it on and off from the right side is best.

The first two times I took it out on the left side and that caused a lot of problems because of the black piece of plastic with the hole in it located just above the transmission. This thing stick out and catches on the accelerator pump.
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Going out on the right side, care has to be taken not to whack the Neutral switch.
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After working the carbs in a bit I attach the throttle cables. Be sure you know which is which! Because the Pull cable wraps around the cam it's a bit more curved than the push cable.
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Insert the pull cable first! Then, the push cable. To insert them you have to slide tabs in from the side. On my bike they don't fit through the big opening where you'd expect to just slip them in. So, slide them in from the side and put the cable through the big opening. I gave up trying it the other way a long time ago!
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If you know where the adjustment nuts go, you can snug those up at this point. It's much easier to do it now. Add loc-tite at this point if you want. Yellow loc-tite color is great as it's not too hard. Blue is fine, but never use red loc-tite for this - I belive it's perminate.
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I attach the choke cable only after I've attached the throttle cables. I just find it easier to do it this way.

When taking the carbs out I removed the right air cleaner boot. It came out easily by folding it as shown here.
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When I reinstalled it, I installed it from inside the air box.It took a little work to get it into the right position. Make sure the R and L of the boots are in the up-right position to ensure they are correctly installed.

Also, make sure that the boots are completely seated in the air box. It's a real pain but this is the easiest way I've found so far to remove and install the carbs.


Make certain that your boots completely seat the throttle body. Here, the boot is not on all the way!
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It needs to fit nice and snug like this
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After you get the air clearner boots installed in the right place and clampped down, bolt on the cylinder insulator

(front boot) and clamp it down too.
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Hook up your vacuum lines, fuel overflow and fuel line.
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Only thing left to do is connect the battery! Be sure to always remove negative first when taking the battery out.

And attach positive first when installing the battery. This way you won't short anything out if your wrench touches the frame while bolting the cables on.

Well, that's mostly it. It's not all the pics I took but enough to let you know what's going on!
I'm sooooooo happy it's finally working correctly now!

_________________
Do you know what it's like to fall in the mud and get kicked, in the head, by an iron boot? Of course you don't--no one does--that never happens. - Capt. Rex Kramer

1986 Honda CMX450C - Jola
1978 Honda GL1000 - Piper


Last edited by paultjack on Tue Jul 21, 2009 5:30 am, edited 1 time in total.

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 Post subject: excellent
PostPosted: Thu Mar 13, 2008 10:26 pm 
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State/Province: NH
City: Laconia
Nice job! All that because of a small burr in the metal sleeve of the needle. Carbs are so delicate that I don't think I'd trust them to a shop. Only the owner of the bike should deal with the carb because the smallest error will only cause the owner grief. The mechanic will not care at all and will still get paid. It's inconceivable that a mechanic would do the work you did on that carb. Every shop I know would just say "live with it" or "replace the carb" They would never hunt down and fix that burr. But that won't stop them from charging $450 to replace your charcoal canister on the off chance it'll fix the idle problem.
Your tutorial should help many 450cc owners in the future. You rock.


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 Post subject: california bike
PostPosted: Thu Mar 13, 2008 11:53 pm 
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That must be an East Coast Rebel because I now notice it doesn't have the emissions tubing that are stock on the '86 California model. The carb itself is the same but other users (like me) might wonder why you don't have all the hoses on the top. Because California required certain emissions recapture (blowby exhaust, fuel vapor). If I get a chance I'll post some pics of a Calif. model for comparison.


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PostPosted: Fri Mar 14, 2008 5:31 am 
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Thank you, thank you...

I think my write-up took longer than taking all the pictures, fixing the carb and reinstalling! I think it took me close to 3 hours to write all that and get it organized.

I've been thinking about it though and I never really explained why having the needle up was causing my carb to run lean.

Here's my understanding of why:
During idle the throttle plate is closed and the engine is struggling to suck fuel and air through the carb. This allows the air pressure behind the throttle plate to build and helps draw the fuel through the idle jet. It's the only opening available to feed fuel to the carb at this point. The needle valve could have been completely open and it would not make any difference because the fast jet is behind the throttle plate. Therefore it doesn't have any real air drawing fuel through it.

But, as I would start to accelerate the throttle plate starts to open allowing more of the tiny slow jets to start feeding fuel. At this point the needle does have an effect on the air pressure building in the carb. Because the valve was slightly open fuel was trying to be drawn from both the slow and fast jet. And because there wasn't enough to pull from the fast jet the engine is relying on the slow jet. But, because the fast was open there was not enough fuel being drawn through the slow jets. Only when the engine got reving enough to really start drawing the needle valve up could the fast jet start supplying fuel again.

It's a delicate balance of air pressure that causes the correct amount of fuel to be drawn up and out of the carb. You have two pressure points - air entering the carb (at the air cleaner) and exiting the carb (at the cylinder)

You want positive pressure at the air cleaner side and this is caused by the throttle plate - it blocks the flow of air into the carb. On the other side, because the engine is drawing the air into the cylinder there is a negative pressure. This allows the fuel to be pushed (or you could say drawn) from one side of the carb up and out the jets.

If the pressure on both sides of the throttle plate are equal you don't get any fuel movement. And this was the condition I was having. Only when the vacuum on the engine side got great enough did it start working again.
Well, I hope I haven't totally messed up on Carb theory! Anyway, I learned most of this from the FAQ I posted about "How Carbs Work" in the FAQ section. But, reading something and understanding how it work are two separate things. From reading the FAQ I figured out that the problem was in the slow jets. And that's what I kept focusing on when I was trying to clean them. I tried thin wires, solvents, air hose... on those slow jets thinking something must be blocking them.

When I would put the carbs back together I would never notice the needle was sticking because it's spring loaded in the piston. The piston was always sitting at the correct height and had good free movement. So it was not noticeable. It's the classic, "Nothing to see here! Move Along" story.

And, in honesty, I was about to give up. I'd been monitoring the carbs for sale on eBay along with the request for carb information on this site. Wow, there's been a lot lately! If I couldn't get it fixed this time I was going to call Jack and get a set of carbs from him. Especially after he just posted he had some ready to go! Sorry Jack, you lost a sale due to my perseverance. But, you'll always be on the Top of my To Call if I get stuck! And anytime someone asks me where I can get parts for my Rebel I always tell them, Call Jack!

OK, off to add features to the PhotoSizer program!
:cheers:

_________________
Do you know what it's like to fall in the mud and get kicked, in the head, by an iron boot? Of course you don't--no one does--that never happens. - Capt. Rex Kramer

1986 Honda CMX450C - Jola
1978 Honda GL1000 - Piper


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PostPosted: Fri Mar 14, 2008 8:41 am 
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Thank you for taking all of that time to post this tutorial! Well done and very much appreciated!

:cheers:

Allaina

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PostPosted: Fri Mar 14, 2008 10:51 am 
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yeah - what she said ... good post good pics :bikerthumb:

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PostPosted: Fri Mar 14, 2008 1:41 pm 
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That write up was fantastic! Amazing patience and persistance.

I will definatly use this info when I pull apart my bike next weekend.

:bikerthumb:


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PostPosted: Fri Mar 14, 2008 6:12 pm 
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Great job, lad.
I may just try the right-side install when I put my carbs back on. I've been doing the left-side install, mostly because I put the throttle and choke cables on before shoving them into place. Gotta give this a try.
brent


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PostPosted: Wed Mar 19, 2008 9:33 pm 
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Great write up :)

If I may interject a tip I picked up last season -

I was rebuilding a rack that had sat long enough to gum up the jets pretty bad. I had taken them apart and cleaned them with Mercury PowerTune and compressed air, but the jets plugged again within a month.

I took the carbs apart again and cleaned with PowerTune. Then I took an ultrasonic cleaner we had lying around the shop, filled it with some PPG DX579 Metal prep (like this) and tossed the jets in for a quick bath.

I couldn't believe the volume of garbage that came out after I had cleaned them by hand. Rinsed the jets out and put them back in the bike. It has ran flawlessly to this day (well it is still in storage now, but you get the idea) :)

You can usually pick up these smaller ultrasonic cleaners for a reasonable price at many hardware stores, pawn shops, etc... They also come in handy for cleaning up all sorts of other stuff, too!

I'm using this technique for all my carb rebuilds now.

Hope this helps someone out!
Tom O.

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PostPosted: Fri Mar 21, 2008 11:05 am 
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Quote:
A little about the slow jet and idle jet.
Here you see several holes on the bottom of the throttle body. The one in the middle on the bottom is the idle.

When the throttle plate is closed this is where the carb gets its fuel. In the middle of the photo you see 4 additional holes. These are the slow jets. As the throttle plate starts to open more and more of these holes start feeding fuel into the carb. They are there to keep the carb going until there is enough vacuum created to activate the piston thus letting in more fuel through the fast jet.

Also, in this pic you see another hole on the right side. This is the choke, more correctly called the fuel enricher. It feeds off the slow jet and provides lots more fuel. Keep your choke on and you're just dumping fuel into the carb!


How do you clean these jets? I tried sticking a needle in them but had a hard time keeping the throttle plate up. When I managed to get it into one of them it didn't go in very far. I don't have an air compressor so I can't blow any of them out. For the moment I have them soaking in SeaFoam. Any suggestions?

Thanks all!!! :D

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PostPosted: Fri Mar 21, 2008 12:36 pm 
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:twisted: Yeah, keepting that throttle open is a real bear!!!

I have a special tool that I made to keep that sucker open! I guess I should have shown my "Tool"!!! LOL but when you find out what it is you'll have a good laugh!!! :lol:

It's simply a thick piece of rubber! I'm surprised it didn't show up in any of the photos. I opened the throttle and shoved a piece of rubber cut to size between the cam that the throttle cables go on and the mounting bracket. So, it's not inside the carbs, but on the outside. It was really handy.


If you need thick rubber like this it's easy to get. The piece I have is 1/4 inch thick. I got this piece when I went to a hardware store. It's a coupling used to join two pipes together. They come in various sizes so get a large one and you won't have to deal too much with curved rubber when you cut it down. With it being this thick it's realy sturdy and it doesn't scratch anything. I used it shock mounting when mounting my new gas tank.

Another note, I would not hold open the throttle by using the throttle plate (I think this actually called a butterfly). It might be just me but I'd be worried that I would knock out of adjustment/bend it. It's fairly sturdy but it's just one of the things I wouldn't want to have messed up. Also, be careful when handling it. The edge is very sharp!

_________________
Do you know what it's like to fall in the mud and get kicked, in the head, by an iron boot? Of course you don't--no one does--that never happens. - Capt. Rex Kramer

1986 Honda CMX450C - Jola
1978 Honda GL1000 - Piper


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PostPosted: Fri Mar 21, 2008 12:46 pm 
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OK, that last post was only about keeping the throttle open...

Cleaning the jets.

The ones you remove from the bottom (fast jet, fast jet holder and slow jet), those you remove and soak in cleaner. I've tried various products, goof-off, denatured alcohol, carb-cleaner, sea-foam... What worked best was elbow grease!

Soaking them helped removed a lot of the gunk, but by using a magnifying glass and tooth picks I could target specific areas and scrub them throughly clean. Just keep soaking and scrubbing.

For the inside, I actually used trashbag ties! Those cardboard and wire things... They worked great when stuck inside and twisted around and around. It made a great little scrubber.

Note that the very tiny hole in the slow jet is still smaller than the tiny wire in the trashbag tie. So, don't try to shove it in side that hole.

Now, for the holes in the carb throttle body... That's another story. If you need to clean those, the best solution is going to be running your rebel with sea foam in the gas. It will, with time, remove all the varnish build-up on these parts. However, if you have something stuck in there like a HUGE piece of rust then you're going to have to blow it out with some good compressed air. Remove the jets from the bottom of the carb and then from inside the throttle body blow anything stuck in there back the way it came. Hopefully you'll get it out. I doubt that you'd have anything so perminate stuck in there, though.

The last method involves removing all rubber parts, even the banjo, and soaking the carbs in cleaner or an ultrasonic cleaner. That'll take a real commitment though.

And, that's how you clean the jets!

_________________
Do you know what it's like to fall in the mud and get kicked, in the head, by an iron boot? Of course you don't--no one does--that never happens. - Capt. Rex Kramer

1986 Honda CMX450C - Jola
1978 Honda GL1000 - Piper


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PostPosted: Fri Mar 21, 2008 1:32 pm 
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I don't know if anything is stuck in them or not. I took the lower parts apart and gently cleaned them as best I could using a needle to poke through the holes of the jets and soaking them in SeaFoam. My problem is that the bike will start and will idle just fine, but as soon as I throttle it at all it stalls. It's like the air is rushing into the engine without any gas. I was thinking as I read paultjack's post that maybe the accelerator pump is at fault or the ports feeding it are clogged. I think I missed that on my last cleaning attempt.

Thanks for your help!

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PostPosted: Fri Mar 21, 2008 5:36 pm 
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A bread-wrapper tie should fit through the slow jet holes.

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John, 2014 CB500XA (Daily Rider), 2009 CRF230L (L'il Red Piglet), 1989 NX250 - sold, 2001 Rebel - sold
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PostPosted: Fri Mar 21, 2008 6:35 pm 
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DRATS!!! I had a huge post of things to do and I pressed and that caused my web browser to go "Back" and I lost it all! :-( My Bad!

So, now you'll get the "Quick" Version...


I'm going to assume you have the 250 so be sure to check out the parts list for the 250 carb - Thanks MR for posting this!

Rebel 250 Carb


- I'm going to say it's not the accelerator pump. That only gives a squirt of fuel and after the squirt is gone it sounds like your engine is still running rough.

- Verify it's both cylinders. Have someone roll on the throttle while you hold your hands behind the mufflers. You'll be able to tell if it's one or both cylinders that's missing.

- Check to verify it's running lean. Squirt starter spray in the air box while rolling on the accelerator. If it's running lean the starter spray will cause it to run great for a moment. If it's running rich the starter spray isn't going to help...

- If you can remove the carb then you're in great shape! There's really only a few things that could be wrong.

- Make absolutly certain that the slow and fast jets are completely clean. Since even a dirty jet will allow your engine to run it sounds like you have another problem.

- Verify that the Needle for the Fast Jet is working properly. Remember, this is where I was having the real problem! You need to make sure that the needle is moving all the way down and closing off the fast jet. That's why I took the jet needle out of the vacuum cylinder and inserted it into the guide. That way I could see exactly what it was doing. Looking at the 250 parts list I don't know if you have a guide like I did. Anyway, you have to make certain that his is working smoothly! It has to move up and down without sticking anywhere, expecially sticking in the open position.

- I verified the slow jets were clear by sticking a very tiny copper wire into each hole. It was pretty small wire! But, I could confirm that each hole was open. If they are open then sea foam can clean any gunk that accumulates. Just add the sea foam to your gas and keep running the engine. (but this doesn't sound like your problem)

- Verify that the rubber part of the vacuum cylinder is not torn anywhere! Any tears and that thing is toast!

- Check that the float valve is working correctly, that the float moves freely and that the valve is not damaged. It's rubber tipped and needs to be in great shape.


That's the basics of what to check. Now, a quick re-cap on carb basics.

Air coming into the carb has Positive Pressure. Air exiting the carb has Negative pressure. If the pressure on both sides of the throttle plate are the same you will not get any fuel movement. This is caused by a vacuum leak (like what was wrong with mine). As you start to accelerate, the vacuum moves from the idle to the slow jets and then to the fast jet.

Since you are idling OK it sounds like the slow jet (item 23 on the parts list) is clean. Those small holes (slow jets)in the bottom of the throttle body and the idle are both feed from the slow jet (item 23) So, if it's idling OK then it seems that fuel is moving freely through the jet.

Carbs really are a Rube Goldberg type machine! But, having a solid understanding of what's going on will help you quickly understand why something doesn't work. There really isn't a lot to them so it's fairly simple to isolate the problem. And, these carbs are "almost" as basic as you can get. I actually think they are a work of beauty!

OK, I guess that's enough for the moment. Not sure if it will help or not. I hope I wasn't too technical. I know I didn't explain everything. It's a shame you don't live closer!

Keep asking questions if you can't get it working!

_________________
Do you know what it's like to fall in the mud and get kicked, in the head, by an iron boot? Of course you don't--no one does--that never happens. - Capt. Rex Kramer

1986 Honda CMX450C - Jola
1978 Honda GL1000 - Piper


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PostPosted: Thu Jul 10, 2008 4:47 pm 
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Joined: Oct 20, 2007
Rebel: 450
Country: USA
State/Province: WA
City: Sequim
Hey so new question - when I go to reconnect my choke cable, the metal band that should go in the clamp is too far down - when I raise it to tighten it up, it pulls the whoile cable up so the choke valves open. This is with the lever shut all the way off. I can't seem to buy any extra cable length on the inside and I don't see how to move the metal part it should clamp to - up. The part number on the entire cable is sahowing MM2-000.


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PostPosted: Thu Jul 10, 2008 7:34 pm 
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Joined: Sep 13, 2007
Country: USA
State/Province: MD
City: Woodsboro
Hi NAC,

Not possitive, but from what you've described it sounds like you've got something wrong with the routing of the choke cable. There's not much play with that thing and if it gets stuck on something or isn't in just the right possition it will appear to be too short. Is that what you are experiencing?

_________________
Do you know what it's like to fall in the mud and get kicked, in the head, by an iron boot? Of course you don't--no one does--that never happens. - Capt. Rex Kramer

1986 Honda CMX450C - Jola
1978 Honda GL1000 - Piper


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PostPosted: Thu Jul 10, 2008 11:03 pm 
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Joined: Oct 20, 2007
Rebel: 450
Country: USA
State/Province: WA
City: Sequim
Could be. I'm trying to go off the Honda service manual but even that isn't the best of pictures. Can you describe or show pictures of how you have yours routed? In fact, whoever owned this bike before me has re-routed all the cables and wiring wrong because he didn't have the Honda tri piece that covers the front forks. You would normally route the cables behind it and in front of the lower triple tree.


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PostPosted: Fri Jul 11, 2008 4:39 am 
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Joined: Sep 13, 2007
Country: USA
State/Province: MD
City: Woodsboro
My choke cable was originally routed from the handle bar to in front of the left fork. There's a wire bracket on the frame that holds all the wires and cables from the handle bar. The cable goes through that bracket and then under the gas tank, over the valve cover and back to the carb.

I had probelms when I routed my cable over top of my turn signal which I moved up, that caused the cable to be too short. To give just a tad additional length I've moved the cable out from between the fork and the frame. Now it just goes from the handle bar to the bracket on the frame. That gives a tad bit more cable lenght too.

_________________
Do you know what it's like to fall in the mud and get kicked, in the head, by an iron boot? Of course you don't--no one does--that never happens. - Capt. Rex Kramer

1986 Honda CMX450C - Jola
1978 Honda GL1000 - Piper


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PostPosted: Tue Jul 15, 2008 2:25 pm 
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Joined: Jul 15, 2008
I just pulled my carburator and cleaned it thoroughly and now am having trouble getting all the hoses where they were originally. Can you help me navigate this?? I saw on your pics that the air cutoff goes on the right side of the bike. But where does it go on the side of the bike with the fuel control valve? also the vacuum lines, fuel line, and fuel overflow what does that attach to? I have two nipples coming from the fuel control valve and cannot figure out where to attach them. I have a manual on order but it will take a while. Thanks, Jon


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