How to Clean Motorcycle Carburetors 

binlagin Glad to help. There is nothing complicating about fixing motorcycles. Its all just nuts and bolts going around and around.

JustFixIt99 I was able to get my bike running because of your video! Rode it to work today :) Thanks man

Awesome! Nothing better than riding on a machine that you fixed yourself. There's a certain sense of pride in it that doesn't come from anything else.

JustFixIt99 Especially when my girlfriends father GAVE me the motorcycle. Then said.. come back Wednesday and we'll get it running. He crapped his pants when I rode up on it today :)

lol, theres a good way to impress the father in law :)

+Deagle123 Glad you found it so helpful! Good luck getting yours running again, take it one step at a time and there's really nothing on a motorcycle thats complicated to fix.

Glad to help :) Be sure to like, share, and subscribe

same bike im watching this video for yamaha XJ 750 lol

Glad to hear. I hope to be able to return to these sorts of projects this winter.

Thanks, I'm glad to help. Be sure to like, share, and subscribe

Thanks, I try my best...Ahh Neverdull, up, spent many hours with a tin of that stuff and aluminum car rims.

So you no it works then, it's all so hard work. Everybody looking forward to your finish bike we are cheering you on, shows you what a following this bike has

I too usually use carburetor cleaner. However full disassembly is still the only way to do this properly with consistent results every time. Otherwise your just chasing your tail while your troubleshooting.

You’re welcome, be sure to like, share, and subscribe

HitaDrum19 Hey, First off, the whole WD-40 to check for vacuum leaks thing has never worked for me, even with propane I've never been able to find a leak with a flammable fluid\gas. So take a really good look for cracks etc. Since you say it ran well before I'll assume that the carb's are properly jetted for the pod filters that you have on them. Running well then getting worse after a few miles would point to an electric issue. Typically either the coil or the CDI boxes. Is your meter a digital multi meter? Lastly, it could still be the carbs. Sticking floats could restrict fuel flow into the carb bowls. This would cause the bike to run well, then start to sputter as the fuel is drawn down faster than the needle valves are letting it in. Since pods typically make it much easier to remove a bank of carbs I would start with them. Pull them out and give them a good cleaning. That way we know that fueling is good and you won't be chasing your tail. After that we'll move on to the ignition side.

Glad to help

Glad to have helped... I really have to get around to editing my new videos......

Mladen Saulić Glad to help

+sergio lomeli always glad to help :)

i got to cleaning mine today. i got a good deal on the for 40 from canada to build y project , thanks again .. do you have a vid on the wiring elect stuff ?

Not yet, but hopefully that will be coming this summer

Glad I could help. Be sure to like, share, and subscribe!

Glad you liked it, hopefully it helped you out. Be sure to share, like, and subscribe!

+Nicodemayo Glad it helped. The jets all go in snuggly. Only mixture screws get a certain number of turns out. Most emulsion tubes are keyed and will only fit in one way. I can't remember if the xj750 carbs were or not. Of there is no keyway then it shouldn't matter.

glad to help

Is this on a UK bike? Without knowing the make and model its really hard to say. Your best bet it probably to ask at the parts counter of your local dealer, or if you have a good local bike shop thats been around for a while. Just off hand though, if the intake size has been restricted by limiting the slide travel, I would bet that the jets were changed to reflect this as well.

I have only tried that once. I found it to be a bit of an annoyance as you needed a way to boil a pot of water on your workbench. The heat can also discolour the aluminum castings of the carbs. So I can't really say. If I tried it more than once and had good results then maybe I'd recommend it, but I don't have enough data to go either way. I've also heard of people boiling them in lemon juice..... Personally I've always had luck with solvent. So for me, if it aint broke....

@@JustFixIt99 OK thanks. Yeah I wondered about how to boil water in a garage setting!

@@mrp410 When I tried it I used an old propane camp stove. The issue I had was that it took forever to boil a pot of water big enough to cover the carbs in.... I'm just too impatient for it :)

@@JustFixIt99 me too! Cheers.

blewyourfaceup My first guess would be a dragging brake calliper with a slightly warped disk. Pull the calliper off and hand it out of the way and see if the wheel will spin freely. Does only happen in gear? or is it also repeatable when the bike is in neutral?

I never made one as assembly is the reverse of disassembly. However you are not the first to ask this. The next set of carbs I have in my garage I will make a complete tear down and reassemble video.

@@JustFixIt99 so did you not adjust the float level or just leave it?

@@mikekurtz627 I almost always (99% of the time) don't bother to set the float hight. Its never really an issue unless its been screwed with previously.

Warheroguy Been a while since I filmed this, but I seem to remember it wasn't particularly fun. I seem to remember I slid the carbs in with the engine side facing up and the air box side down. Then rotated the carbs into the engine side intake boots. Then using a flat bladed screwdriver (carefully so as not to poke holes in the boots) coaxed the air box boots around the carbs... Frankly it its pretty fiddly work. All I can say is what ever you do, DO NOT TAKE OFF THE ENGINE SIDE CARB BOOTS!!!! The bolts are almost guaranteed to snap off... then you will hate yourself... Good luck!

JustFixIt99 Thanks! :D And ya, that's just about exactly what I ended up doing. At first I put the carbs on then tried putting those air box side boots on but over the years they just became so stiff it was way to much of a pain, so I used the flat headed screw driver method haha.

Glad ya got it back together. Hows it running now?

Sounds better! Definitely an improvement, but it's running rich still. So have to figure that out. Good learning experience though :)

Could be, I think I made this video almost 10 years ago so I can’t really remember to be honest.

Well if it is completely stripped I’d 1) see if could find an extremely small easy out type extractor, 2) carefully begin drilling it out until I could use a pick or the like to coax out the remaining threads or fold it into the center to remove it in pieces. Failing all of that, finding a used carb body on eBay or Craigslist may be a path to keep in mind. Good luck!

No!!!! lol, the carb cleaner will attack the rubber parts. Which is why you disassemble and remove them all before cleaning. The diaphragms themselves should be wiped to remove any dirt if its present with a soft cloth, without any solvents.

JustFixIt99 awesome thanks I figured but wanted to know what to clean them with also so thanks. Great vid btw

No problem, glad to help. Be sure to share, like, and subscribe :)

I don’t have an ultrasonic cleaner.

I wasn't really planning on a part two. Is there a question you had that I left unanswered?

Yes. Some carburetors have an alignment pin so the emulsion tube (the thing your talking about) will only slide in in one orientation. Others don't care which way they go in.

@@JustFixIt99 alright thanks man, I'll message you if I run into any problems. I got a 82 maxim 550 and I got it running on starting fluid but need to get it running on gas.

Is the screw leaking fuel when the bike is running? If not then I wouldn't worry about it too much. I've never actually used a drain screw on any bike I've owned. I don't see any way to replace the bowl without removing the all the carbs though as the screws will require quite a bit of force to get out ofter all these years, and probably vice grips as I show in the video.

no it's seems to be sealed up just fine. that's good to know, a ease of mind haha. thank you! your video helped me out big time.

Glad to help

Its always good practice to check and set the float hight. That being said I almost never do and have never had any issue.

As in back into the bike? That is usually the tricky part. Usually I find a bank of carbs likes to go back into the side of the bike it came out of. I start by sliding the bank in with the side that faces the engine tilted up, placing the bottom edge of each carb on there respective boot. Then I rotate the bank up into position while at the same time pushing the carbs into their boots.

Never used triflow, but If I see it I'll pick up a can and see how it works. I've had pretty good luck with both PB blaster and Releasall, but am always willing to try new things.

It's work on chains to

Do they still make a product call chain lube a self drying chain lube

No idea, I've always used chain wax

Never heard of it, I hope it's great stuff for you. Now the new chain have one rings too. Wish we would have have them to, they were a pain to clean, now they have solvent instead of gas,, we use to heat up oil and kinda boil our clean chains. Shows how old I am, I was 21 when I bought my 750 and paid 1900.00 for it, I got one of first in southern California. 1970

I’m not a seca expert by any means, but I’d be glad to try and answer your questions.

Have you accurately set the float heights using the correct factory setting? Other first guess would be a leaky bowl drain screw, or if the o-rings that join the carb fuel supply lines in between the carbs.

@@JustFixIt99 thanks for the reply. No I haven't set the floats, the bike was running fine then this. It's ok some days and some days it's drip drip drip. I'll check the feed line, I guess I need to split the carbs to get at it? Just re-read an earlier reply off of you... I de- restricted the carbs last summer and you said they might have been re jetted for the restrictors.. could this be the problem? The problem seems to coincide with the removal of the top hats in the vacuum Chambers.

@@tamar5261 Can you tell me, or describe exactly what you did to derestrict the carbs? We didn't get restricted models here so I'm a little hazy on that. If you haven't done so yet, be sure to read your plugs to make sure you're not running lean. I would maybe compare the jets in your carb (should have a size stamped on them) to the size speced for markets that weren't restricted to see what the factory did. I can more or less say however that it very unlikely that derestricting it caused the leak. To change the o-rings you would indeed need to split the carbs. Perhaps when its dripping you could get in there with a mirror, or a borescope and see where it's coming from. It would make troubleshooting this easier.

@@JustFixIt99 in the vacuum Chambers were little plastic things that look like top hats, they stopped the sliders from opening up fully. They only opened up about 25pc. I will definitely pull the carbs apart soon, the mirror thing is a good idea as I suspect it's an o ring somewhere along the line hopefully.

@@tamar5261 I would strongly suggest checking your jetting. I would be shocked if it wasn't running lean. Be very careful as you can easily melt pistons that way... ask me how I know....

I didn't film the reassembly. As I mentioned its really just putting it all back together how it came apart. The only thing to watch is how many turns out you set all the mixture screws, which should be available in the service manual, or from a quick google search. If you think it would be useful, when I do the carbs on my current project I'll show the reassembly.

Hmmm, thats a new one. maybe try pushing down on the top of the emulsion tube with something like a pencil eraser that won't damage it to hold it in place while you turn it? You might need to get progressively more destructive with holding the tubes in place. If you do destroy them odds are you can still buy them in a carb kit. As a last resort I would try an impact gun on them.

A new one? Darn! I was hoping this was a common problem -my luck. I've left the carb rack in the freezer in the hopes of creating a tighter fit for the pressed in tubes and will apply a "gripper" to the tubes from inside the venturi in the hopes of breaking the jets loose. We'll see.

I'm afraid not, I've cleaned a lot of carbs and never had that issue.....

Well, I fixed it...I doubt few have ever heard the following sentence: "I rebuilt my carbs with a handheld high speed grinder". But it actually worked. I carefully ground the heads off each jet and the tubes simply dropped out. Then a little torch heat and some pliers and the leftover jet screwed out way too easily. So next time anyone posts a "how to rebuild carbs" video please add high speed grinder under the list of tools needed. On a more serious note, any advice when I reinstall the tubes once I get my new Jets. I am thinking they will just spin before I can get any serious tightening happening.

The vast majority or carbs I've seen have the emulsion tubes keyed so they can't rotate and only fit in one way. I wonder if yours are missing or sheered off.....

They remained stuck to the float bowls when I took them off. I didn't see a pint in damaging them by trying to remove them as in my experience if you don't disturb them they rarely leak when reused.

Dirty carburetors can cause both the problems you mention. It is also the first diagnostic step to getting a bike running correctly. Once the carbs are clean you can move on to other possibilities. Otherwise you'll more than likely be chasing your tail.

JustFixIt99 Yeah but it would be a bummer to remove, clean. reinstall the carbs just to find out that your rings or valves are causing a leak.

se7ensnakes Yes that is a possibility, but with old bikes that's just the way it goes. Carburetors are always the first port of call. Rings\valves probably wouldn't cause a low idle\stalling.....

sadly not

+Stephen Copeland I did end up paring it all out, Everything but the frame and the short block was sold off

on ebay there is one for 300 dollars

+Antonis E Sorry, sold them a long time ago. As for the other carbs, you'd have to look up the flow specs for them. I would suspect if the throat sizes are the same then they should be ok. I'm not familial off had with the carbs your using. Are they slide or CV? If you are converting to slide, usually you go a little smaller I believe.

Stan Rose as long as your careful you won't hurt anything