Gday all. I just rebuilt the top end on my 97 kx rebored to 265cc. When I first rode it about 5mins it cut out and stalled in 3rd gear. Lost all power and died. I kicked it over it started fine. The next time I rode it wouldnt start with choke on and took like 20 kicks to start it. When it did start if I pulled the choke on the revs increased. I rode it for about 10 minutes then all of a sudden 4th gear flat it died again. The wheel didnt lock up just lost all power I pulled in clutch and then released trying to bump start it but nothing. I checked plug it was fine then I kicked it over took 4 kicks and it fired. It has fuckloads of power revs untill the cows come home and is scary powerful. When I got home and shut it down smoke poured ftom the baffel for like 2mins. What could be wrong. Crankshaft seals???
250 what could be wrong 97 kx250
- Thread starter jimsowen
- Start date
If your crank seals were the problem for the smoke, your plug would be black and spooged, you stated it looked good though?.....you have fresh gas in the tank? Maybe clean carb and set float, but the way you describe the problem it almost sounds electrical, maybe two problems?.....inspect the plug again and go from there.
I was thinking a fresh rebuild, did you use a lot of oil in the cylinder and crank case when putting it back together? it could have pushed all the oil out into the pipe and it is just residual oil burning off.
fuel, air and spark at the right time to run. Compression, reeds, dirty air filter, kill button, wires pinched or burning on pipe, loose ground under the tank, bad plug cap, etc.
By the sounds its either fuel or electrical...DUH...but it is possible that it is a momentary seizure too. So, does it seem that the motor slows or bogs just a little before it quits? This could be a fuel flow problem or too lean on jetting due to plugged jets, gas cap vent, float level too low..............
By the sounds its either fuel or electrical...DUH...but it is possible that it is a momentary seizure too. So, does it seem that the motor slows or bogs just a little before it quits? This could be a fuel flow problem or too lean on jetting due to plugged jets, gas cap vent, float level too low..............
Its got mass compression, I cleaned carby after the rebuild before I started it. Air filter is fine. First start after rebuild it started on the 3rd kick. I did 2 heat cycles then the next day I took it for a 5 min slow ride it started on 3rd kick with choke on. After 4mins it bogged down in 3rd gear lost all power and stalled. Back wheel didnt lock up but had no engine noise/power. I kicked it over started back up first kick. I got it home and found that it it was weeping coolant from the outside of the head. I ripped off the head and found coolant on top of the piston. I cleaned it up and used the old reuseable head gasket and it wasnt leaking in or out side of the head after the ride. It took a bit to start and would not fire with the choke on. I took it for a easy ride that time. The next time I rode it it wouldnt start with choke on and took atleast 20 kicks to start with choke off. I warmed it up then went for a 15min ride at about 12mins it lost all power and bogged down then stalled. I pulled in clutch then released to try and bump start it but nothing. I pulled out plug and inspected it was on the lean side at a greyish colour but not fully white.
that plug doesnt look LEAN to me. Just the opposite, but not badly so and not for a breakin situation anyway. FYI lean jetting due to the jet size won't make a running and getting warmer by the second motor stop running unless it seized. if your flow level is too LOW it will feel like it ran out of fuel. which is what it is actually doing.
bad stators do crazy things and make you look and look and look at other things, so a multimeter test of yours may be a good idea, easy and cheap even if you have to buy said multi meter.
bad stators do crazy things and make you look and look and look at other things, so a multimeter test of yours may be a good idea, easy and cheap even if you have to buy said multi meter.
I think carb needs to be jetted for big bore kit not enough fuel is killing the bike and i would get a better spark plug made for your configuration
Welcome. This is a site where you can learn something about jetting for bigbore kits if you ask.
I already am a mechanic i was commenting on the topic