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Yamaha carb rebuild


beemerboy

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This obviously isn't about our beloved BMW brand but I'm hoping for feedback, advice, pitfalls, warm fuzzies, etc., as I begin to dig into rebuilding the carbs on a 1982 Yamaha XJ550 Maxim.

 

I've got a Clymer's shop manual on the way but while it may tell me how to go about a carb rebuild it's not like getting sage advice from someone whose BTDT. One thing I know is that one or more of the carbs has flooded and leaked fuel into the crankcase. That's because the new owner (that would be me) didn't shut off the petcock.

 

The local dealer doesn't list a rebuild kit which brings up my other question; Who, on the internet, offers such parts for older Japanese bikes?

 

TIA!

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grizzly660fan

there are several dealers online who should be able to help. Yamaha's web site itself has parts diagrams online.

 

http://www.starmotorcycles.com/star/parts/home.aspx

 

I buy yamaha parts from Lake Hill Motors in Mississippi. They are not sophisticated but able to get me all the parts I need at a very good price. you will have to phone them, they have an 800 number, shop around and then check them last to see if you get a good price or not.

 

http://www.yamahadiscountprices.com/

 

I have no affiliation with that dealer, just have ordered many parts from them over the years and had good service.

 

good luck,

Garry

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Having rebuilt only two carbs in my life (BSA's amal and whatever was on mid 60s chevy van's strait six), it sounds as if the float's needle valve isn't working. In carb's bottom/bowl is float (much like in some toilet tanks and/or swamp coolers) which pushes on plastic tipped brass fitting (float's needle valve) to stop the flow of gas into the carb's bowl. Sometimes solution is as easy as removing bowl and cleaning out crud which interfers with float's needle valve: other times (given age of the bike/carb this is probably it) plastic tip of float's needle valve has degraded and isn't doing its job.

So, on the up side, replacing float's needle valve maybe all that's needed. On the down side, where to buy float's needle valve for 24 year old model is a puzzel.

 

Good luck,

 

Wooster

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celebrationrev

I rebuilt the carbs on my XS1100. The second rebuild in the 5 years I owned the bike. And at that point I swore my next bike would be injected; no more carbs!!

I don't remember where I got my kit, but it was probably through the internet. If you haven't already been there check out XS1100.com. I know your bike isn't an 1100 but many of the resources will apply.

The most critical part of those carbs is the float level - getting them right and in synch with each other. I used a straight edge across the bowls for the latter and used the trial and error method for the former. It's just a matter of bending the tab to set the level but it's a bugger to do in tiny increments. And the tolerance is farily small.

If you do have a bad needle valve your best bet is eBay or that XS site. I got stuff there from guys who had parts bikes. Always found them eager and helpful.

But if you had fuel leaking another likely trouble spot is that petcock. Do you turn it off? Not necessary. Unlike all other bikes the XS series uses a vacuum valve and a 4-position petcock. "Off" means no fuel no-how. "On" means fuel when the vacuum of the engine calls for it. "Prime" means free-flowing fuel; basically a gravity feed. "Reserve" is self explanatory. Just put it on "On" and forget about it. I only turned mine to "off" for the winter, and to "prime" when spring arrived (to get it running that first time) or when I'd had the carbs out.

YMMV!! I'm assuming you've got the same set-up as the XS1100. If not, all bets are off and ignore ALL of the above.

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Thanks, Gents, this is the kind of info I'm looking for! More warm fuzzies, please!! Oh, and a bottle of vodka to help clean the carbs. tongue.gif

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