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Old 10-04-2009, 07:53 AM
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Wildkat Wildkat is offline
XS Special Gurette
Join Date: Apr 2004
Location: Location, Location
Posts: 3,406
Upon reassembly...

First, let's talk about cleaning. Number one, a compressed air source is mandatory for cleaning these. You have to be able to blow air through all the various passages to be sure they're clear or you'll likely be wasting your time. Second, you can't get these too clean; the slightest bit of crud left behind can come back and haunt you. Make sure every part, passage, opening, and hole is as clean as possible. There used to be a lot of talk about 'triple-cleaning' these carbs, that was simply because owners weren't getting them clean enough the first two times...

Next, what are you going to use to clean them? This can depend on so many factors; how much do you want to spend, how bad are your carbs, what is available to you? The best/strongest cleaners IMO are either the Yamaha carb dip cleaner (available through your local dealer) or Berrymans Chem-dip (available at most auto parts stores). Price-wise I believe they're about the same (about $25-30 for a gallon container), but there is one major difference. The Yamaha dip is safe on rubber parts, the Berrymans isn't; put rubber parts into that and it will destroy them. I (Crazy Steve) personally use the Berrymans as I haven't found any crud it won't remove. But if you find you need to dip the whole carb body in the Berrymans, you'll need to remove the throttle shafts to protect it's seals (for this, search the forum; it's been covered as to the best methods). From there, some have had success with Pine-sol, Simple Green, spray-can carb cleaner (also very damaging to rubber parts, so don't soak rubber in it) and maybe a few other cleaners, as well as ultrasonic cleaners and heating the cleaning solution. Again, there's been a lot of discussion in the forums as to different cleaning methods, pick one that you think will work for you. I'd highly recommend that you soak all the small metal parts (particularly the jets) in carb cleaner, at least the stuff you can buy in spray cans. You can use gas or thinner to clean the exterior of the carbs. Be safe whatever you use, wear eye protection, etc, etc...

Finally, parts. There's multiple suppliers, some will have everything you need, some will only have certain parts. Favorites on this forum are:,,, and last but not least, eBay seller 'georgefix' who probably has the best over-all selection of rebuild kits. Do verify that replacement parts are correct before installing (particularly the pilot jets) as there has been issues with incorrect parts being furnished. For best results, most owners report genuine Mikuni jets perform better, so don't be quick to throw away your undamaged stock jets. New Mikuni jets can be purchased at nearly any metric bike dealer as well as online and aren't that expensive.

OK, you've got everything clean enough to pass a white-glove inspection. Reassembly is pretty much just a matter of putting the carbs back together. We'll note the 'special' places that need particular attention, so let's go...

Make sure you take note of the notch and pin when putting the emulsion tube back into place... don't force this.

The tube does NOT go in from this side... It's sitting here for the picture ONLY... (Thank you Don)

The notch in the emulsion tube should fit on this pin.

Also.. make sure you clean this particular tunnel in the float bowl... and it WILL hit you in the eye as it goes through if you aren't careful... DAMHIKIJD

By the way... a MAJOR thanks to John for being so patient in teaching me all of this...

Of course, you'll have to set some stuff; the float levels and a rough 'set' on the idle screws; you should also check for 'bench sync' (making sure the throttle openings are equal), if you've disturbed the linkage or had the carb rack apart, you need to do this; look here:

For the floats, if you have brass units, set them to 1" (+/- .040") from the gasket surface to the top of the float with the carb upside down. The plastic floats should be set to .906" (+/- .020"). Note this isn't year-specific, but depends on the float type; if you install plastic floats in early carbs use this number. The '81-82 carbs have a rather involved setting process, you'll find that discussed in the forums as well as in the service manual, but this number will get you close on those. Make sure you check both sides, sometimes the float can be twisted; adjust as needed. In any case, I'd highly recommend referring to the repair manual for specific information and diagrams. You may need to adjust the floats up or down depending on your combination while you tune the bike. Use one of these: ... to get your float levels precise; your bike will thank you.

For the idle screws, about 1 1/2 turns out from lightly seated will be a good start for the early carbs, about 2 to 2 1/2 for the late carbs. This will just be a starting point, you'll still need to sync/adjust these for best performance on your bike.

Again, thanks to Wildkat and Maans Smit for the original posts, hope this is helpful!

Last edited by crazy steve; 04-01-2012 at 09:39 AM.