BoCephas

Actually it’s a keihin which I think is Japanese. That’s why I was willing to pay what I did, because everyone, including two Honda dealers, told me to stay away from Chinese products. Accordingly to the dealers, that’s what they came out with in 86

Oh, ok then. Do you need the model number of my carb?

Ok will try the polish trick. Doesn’t seem to be hanging up but will try. Yes the fifty bucks plus shipping sounds good. Can you put me touch with this guy?

Well to give some background, I bought an oem identical carb off eBay. Actually talked on the phone. This guy had over 60,000 positives so I trusted him. Carb came in clean as a whistle, but I blew thru all the ports to be sure. Put in a shindy kit. I then ran a half gallon of gas thru the tank into a clear container. No rust or anything. Pulled petcock and screen Was perfectly clean. Got my nose, mirror and light down on the tank and searched For foreign objects stuck to the sides. Nothing. ran more gas thru it and then filled with ethonal-free gas. just spent 120 bucks on this carb. Probably be worth having a good spare but have my 420 in the shop getting starter replaced so money is short. What I can’t understand is the idle at both extremes. Pulled the top off the carb and made sure the slide was not hanging up. Also when driving it runs smooth, so ...?

Make that oem carb

Hope someone sees this and replies. My carb has gone south after running great since August. Extreme fast idle on start, and too low when warm (it dies) I can not find any leak at the boot when spraying. Only thing different is I filled the gas tank with ethonal-free and it has run great the first quarter tank or so. After pulling installing carb so many times that I can do it with my eyes closed, thought the problem was fixed. Ready to sell... hoping for suggestions...’86 250 FourTrax, replacement identical Orem keinlin carb

Kind of a late reply, but here it is. Years ago I bent my right thumb back further than it was designed to go. Could not touch anything with it. This was right before deer season. A friend gave me a twist throttle kit ( he wasn’t racing anymore) and I installed it. Having rode motorcycles for years, I had no problem with it, but then I was just riding back and forth to my stand (1/2 mile). As soon as deer season was over and my thumb healed, I went back to the thumb throttle, as my son rode this rancher too, and I can see how a twist throttle could be a problem, especially if you were to have a lead foot (or thumb). I agree with the above comments, stick with the thumb throttle, unless you mess up your right thumb right before deer season!

I will try to post a picture of this mess when I get it apart again. Maybe it’s not the cause of it not running.

I think this oem is beyond help

Oh I have, but the carb was previously mutilated in the area of the main jet needle, and the lower guide or jet was punched in (I guess) and then centerpunched to “lock” in place (I assume) and then some grinding was done, probably with a dremel, to supposedly clean up the mess,I suppose. The bore is not rough but very rough- looking as you can imagine. I put a shindy kit in because it was running, just not well. Whoever did this mutilation probably puts cam bearings in with hammer and punch. I just want to trash this and get another carb if that’s feasible

I have noticed there are many different Carbs on the market that claim to be replacement for an Oem carb. I have read in many places that most don’t actually fit without various modifications. Does anyone know of a particular carb that will replace a keihin on my 86 250 FourTrax with the least amount modification, that will be reliable? thanks in advance

Thanks for all the ideas. So far it’s ok...

Several things have happened since I posted the problem. It would start normally for a few times, then only with starter fluid. After going thru the carb again, 11th time, it would only start and run while choked. Went thru the carb for the 12th time, still found nothing wrong. Sprayed thru all jets again, blew thru all passages. Blew thru vent tubing, still nothing. I had already replaced plug and checked for air leaks. Reinstalled carb, making sure fit at intake boot was tight, as all the other times. This time it started immediately and idled a little rough. Tweaked the pilot screw ever so slightly and it smoothed out. Took it for a ride up over the hill in second gear and it ran like a new one. Back at the house I started and ran it a few minutes and shut it down. Did this several times and it appears to be fixed. I’ll see what tomorrow brings. To answer your question ,shadetree, I haven’t checked compression because it has so much power. Fuel is good, spark is good. If I’ve fixed it, I don’t know exactly what the problem was... thanks for answering my post.

1986 250 FourTrax. Will start 2 or 3 times, then nothing. Shindy carb kit installed, except for slow jet, which was noticeably smaller but stamped 38 like the old one. All jets, passages, bowl etc. cleaned enough to eat off of. Pilot screw (with all items) backed out 2-1/2 turns (not quite, tried for 2-3/8 like book says),new spark plug installed (.024” gap). will start with carb cleaner sprayed and then carb will pick up and keep running. question: why is this necessary after starting like its supposed to a few times?