79" Enticer 250 doing strange things. Picked it up as a project sled, excellant condition, low miles. Would not idle, without thumbing the throttle. Figured a carb rebuild was in order. Ordered a kit from GenuineNOS, cleaned carb, while reassembling noticed gaskets did not quite line up with ALL ports in various places. Re-used original gaskets, as they were OK. After getting the sled back together, gave it a pull or two, and it immediately went WOT, would not idle down at all. Shut it down, checked choke and throttle, all operable. Started it back up, immediately went WOT again. Began the tedious process of carb disassembley again. As I had an old original ET250 as a parts sled, I disassembled the carb on that sled, and proceeded to rebuild the new(to me) one while using the parts one as a pattern. Got it all back together again, started up, and immediately went WOT again! Took out the choke plunger, backed fuel level adjustment out to almost falling out, checked butterfly and throttle cable(OK). Started up again, same thing!!!!! I am totally confused, and am about ready to ditch the Keihin for a new Mikuni round slide. Hate to do it, as I would like to keep the sled original, as well as keeping the oil injection. Can't seem to find any expertise around with these old carbs, and cannot even find a manual that matches the Yamaha -specific Keihin that was used on this sled. Any one got an idea?????? Thanks in advance.......
Crazy Axe
New member
not sure but the crank seals could be bad.. if the engine is drawing air from anywhere other than the carburetor, where it is metered, it will allow it to idle up, given there is enough fuel there. Maybe also check your idle air screw. I saw the light and swapped to mikuni and have had no problems so far but have only had it together for a while. Tuning it is a b*(&ch and unless you are familiar with all of the mikuni parts and figuring where you need to go with them it's not easy at all to get tuned in. BUT once its tuned in, it runs way better.
Also if you need some parts for the carb check out http://www.babbittsonline.com/ they have lots of hard to find parts for these sleds just watch it cuz sometimes the prices are a little steep (like 60 bucks for ONE front shock)
edit: also check your carb flange and the spacer cuz if either are loose it might pull air from there also
Also if you need some parts for the carb check out http://www.babbittsonline.com/ they have lots of hard to find parts for these sleds just watch it cuz sometimes the prices are a little steep (like 60 bucks for ONE front shock)
edit: also check your carb flange and the spacer cuz if either are loose it might pull air from there also
x2 on what crazy axe said.