Carb replacement for an '83 ET300

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Paulver

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Jan 7, 2014
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What "new" carb will fit in an '83 Yammi Enticer 300? The carb that's in it appears to have a problem that isn't "fixable", and we're tired of the issue and trying to figure it out. It idles..... when it wants to, and it'll run like a top.... when it wants to, and it'll bog down on acceleration..... when it wants to!! Changing the pilot jet size up or down renders it useless! Won't start. No matter what, the plugs run black and wet. You can even smell the gas. Not sure, but I think a Kiehin is in it right now. The sled is in a friend's shop right now, so I can't look at it till Monday. The sled was given to me and I have no idea if someone fooled with the carb in the past or not. My instinct tells me that it's been altered in some way.

So......anyway, I think a new carb is in order.

Compression is 108 in one cylinder and 110 in the other. Don't know what the proper compression should be. If anyone can steer us in the right direction, I'd really appreciate it.

Thanks.
 
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Put the carb in an ultrasonic cleaner. The pilot circuit on these carbs is almost impossible to clean. I had this problem on my 440 exciter which also has a keihin carb. I bought an ultrasonic cleaner fro harbor freight. Ran it through for about a 1/2 hour and now it runs perfect. And trust me me I know how to clean carbs. I've owned vmax4's, lol.
Also, if the sled sat for a few years, the gas tank and fuel filter should be pulled cleaned and replaced. Might want to pull the oil tank too. My exciter had sludge in the bottom. But I think it sat for over 3 years.
 
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Guys have gone to new slide carbs on 250s, 300s, 340s. It's doable, but a fair bit of work.

Ultrasonic is probably the best way to go for rehabbing the old one. Those pilot circuits have eensy teensy plumbing that will be crippled by tiny specks of crud.
 
I'm curious why so many swap carbs on enticers. I have 5 of them all with different carbs. Even one with the goofy fuel pump instead of float bowl and they all run great.
 
300 have keihin butterfly, 250 has keihin butterfly with fuel pump, you are correct about the 340. The 440ex have keihin butterfly. They are all very simple to clean except the 250 is a pain with the fuel pump attached. I guess the reason to swap would be parts availability. Some gaskets are not available anymore.
 
I think the biggest stumbling block is the proper cleaning and fuel line restoration, based on the frequency of questions around carbs and related issues.

I haven't run across an unobtainable gasket yet on ETs.
 
Is there no replacement carb for this machine? Has anybody swapped out another carb for this machine? Also, I'm finding absolutely no manual for this particular year sled. What am I missing here?
 
ET 300 or 340 1984 and older are the same carb. Jetting was a little richer on the 340. 85 and up 300/340 carbs can also be used but are a little different because they had a throttle override switch on them which is not needed on 84 and down.

opsled

PS, Finding an off the shelf generic replacement just doesn't happen with Yamaha. You could put on other types of carbs but will need to make them work and will probably lose your oil injection.
 
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