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Viking

1991 YFM 250- Carb Trouble?

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Guess I spoke to soon. Bragged on another thread about how well this bike ran. And it DID. But then I noticed gas leaking from the overflow tube on the carb. Bike still ran great though. Anyway figuring the floats were stuck I removed the carb checked the floats and put back together. Then it wouldn't start. Turn over but no go. But it didn't leak. When I finally got to start it ran like crap. So took carb back off, re checked floats and porting as best as I could.

Re-installed carb and now not only does it run like crap but its leaking fuel from over flow tube even worse.

I've ordered a new carb kit for it.

I'm not real well versed in carberation so I'm trying to proceed carefully.

Any tips tricks or general input is welcome.

Thanks, Mike

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the small twist ties for garbage bags stripped work great getting into the smaller passages. if you have an air compressor, that is a big bonus to get everything blown out. you'll be fine with a new carb kit, you'll find where everything goes. look at the specs for you float height when you get ready to install. if you run into any problems, cheriah is THE carb queen of QC !! pm her and she will help you out and talk you thru it. here's a good read in the meantime ...

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Thanks for the tips. I have an air comp. so I will blow everything out.

I picked up the carb kit and have the carb out.

Should I use any lubricant on the o rings as I put it back together?

Also Kinda unsure of setting float height?

Thanks Mike

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you don't need lube on the rings, with the bowl off the carb, tip the carb upside down and measure from the meeting surface of bowl to top of float. there is a little metal tab that is connected to the needle and should be around 1/2 an inch ...

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Got it all back together with no spare parts :laugh:.

Runs good but not real happy with the idle. Seems like the rpm is up and down. Not constantly but like its about to stall and then doesn't. Or sometimes does.

Big mistake I made was not keeping accurate track of where needles were sitting before taking them out.

I've been playing with the pilot screw to no avail.

I'm thinking the pilot jet, which is located in the float bowl should be tightened all the way. I think I bottomed it out then loosened it a couple of turns.

Also I'm getting white smoke from the exhaust. At least I think its smoke. Could be condensation? Cold and damp here.

Any ideas?

Thanks again for helping out, Mike

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Forgot to update. The plug was fouled. I assume from running with a fouled carb. Cleaned plug and a little more tweaking and it purrs like a kitten again.

Thanks for the help. Always been afraid to play with carbs because of a lack of understanding. I'm far from an expert but I learned alot.

Now I've pulled the carbs apart on my 2 outboards. One is 40 years old and never touched. Gummed up bad. The other had water in the gas a couple years ago and has rust.

Great site.

Mike

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