I picked up my 90 EVO about a month ago, put like 300 or so miles on it, no problems. Its all stock, except S&S tear drop aircleaner, and drag pipes.

I went to start her up the other day, a day after I road quite a bit with no issues, and it fired right up like usual but it died on choke. Got it warmed up and it kept dying on me. Would fire right back up, and randomly cut out, no sputter just like hitting the killswitch while riding. Tried to mess with it yesterday, bike would only idle on choke while I held it up right, if on the kickstand it wouldnt. No choke wouldnt run. I drained the gas (looked yellow and nasty figured that may be it) Put in fresh gas, nothing. Cleaned out the carb today top to bottom, bike fires up and will purr at idle, but as soon as I touch the throttle it dies. Will fire back up and idle. I can get it to rev out sometimes and it feels strong but it backfires quite a bit.

My guess is the VOES switch could be bad? Sounds like it could be a timing issue, because I know the carb is clean now. Going to get plugs tomorrow even though I highly doubt thats the issue....

What else do you guys think this could be? Battery reads full voltage (not a harley/yuasa etc.. knockoff battery but seems to work and be fine)

 

You might check the EVO section. Lots of knowledgeable people there.

 

Did you take the carb apart??. My buddy had a similar problem when he rebuilt his carb. There was a needle he put in backwards or upside down. Can't remember. At idle it was fine. We took off the air cleaner. looked inside the carb, and noticed when giving throttle the carb stop delivering fuel and bike cut off. He sent the carb out to someone and got it rebuilt. The guy told him what it was. It's been fine ever since. I will try to get ahold of him and ask. Maybe it will help you.

 

Didn't even think of it.. think you could move the thread for me?

 

My buddy said there is a small 1/4 piece that goes between the jet it was upside down when he put it back together

 

Maybe check fuel filter screen. Have to drain tank though to get to it.

 

It sounds like your low speed jet is clogged.

 

Pull the the petcock and clean the filter screen. Someone mentioned low speed jet clogged... yeah that as well as float level. Stock carb or aftermarket?

Some are in the habit of adding an unneeded (IMO anyway) additional fuel filter between the hose that feeds the carb. If that goes south you will get the problem you described.

 

Also if you pulled the emulsion tube to clean it and also pulled the needle jet, double check that you put the needle jet in right or it will not run right.

http://www.cv-performance.com/harley...tuning-issues/

 

Needle jet. yes that is the name of the piece