Starts on a backfire...

[Morvo]

My 1995 KX250 has been having serious problems the past few months and I just can't get my head around the problem. It all started with a faulty pickup coil which I replaced with an aftermarket one which I had to fiddle with to get it to fit, it worked fine but the bike kept on fouling plugs and got gradually worse. I changed the jets, leaned the mixture out, changed rings etc... and it was still fouling plugs. In the end I decided to buy a better pickup coil which is a direct replacement for the original kawasaki one.

After fitting this part the bike will only fire on a backfire, inbetween a few kicks where the kickstarter will kick back violently. Once the bike has started it won't rev up without popping and backfiring, if I release the throttle it will die, and if I hold on the throttle it will pop and die!

I asked someone about the pickup coil wiring as there are only two wires which I had to solder to hook it all up, he said if I wired it on wrong the plug wouldn't start at all, but it does, really big blue spark.

What things should I be looking at to resolve this tiresome, tedious, ass of a problem? New stator plate, new CDI unit? The flywheel wooddruff key is still in place and the flywheel is tight. :(

 

[Tdel]

How about a new bottom end or at least a new crank seals. I think you may have been pulling in oil from the crank hence the beginning of your post having to lean up the bike for no reason. This would lead to a rich situation when running unless there is no or low oil in the tranny, then the mixture would go lean and not idle, backfire...

 

[QKENUF4U]

the fouling i think could come from a bad seal at the crank
BUT
the backfireing sounds like it only started after you put the second or third pickup on it. put the other one back on and see if it still does it or just buy a STOCK pickup

 

[Morvo]

How about a new bottom end or at least a new crank seals. I think you may have been pulling in oil from the crank hence the beginning of your post having to lean up the bike for no reason. This would lead to a rich situation when running unless there is no or low oil in the tranny, then the mixture would go lean and not idle, backfire...

There has been no oil loss whatsoever, I should have mentioned that earlier. I think my plug fouling was down to the float heights, which have been adjusted prior to my first post. The thing is though is that this pickup coil should work fine, or so the guy said who supplied it to me. The only thing that I can see wrong with it that i didn't notice before is that where the pickup passes the flywheel raised bit, it isn't bang in the centre, more towards the edge. Would this make a huge difference? I cannot fit the old pickup on again as I binned it as soon as I fitted this latest one :ohmy:

 

[Morvo]

Right, I've just gone ahead and bought another pickup coil from here http://cgi.****.com/****motors/Kawa...cmdZViewItemQQcategoryZ43976QQitemZ4594331004

Apparently it comes with instructions and is the real deal for what I need. If this doesn't work I'm gonna shove my head up my ass and suffercate myself.

Here is the link to the other aftermarket one I bought a while back http://www.electrexworld.co.uk/ if you go to Mx/enduro in the left hand side of the main page and select kawasaki, then go down to KX250 92-97 and its in the column on the right marked 'P10'. As you can see, it looks nothing like the stock one and I had to grind it down to fit! Not very good really is it!?

 

[QKENUF4U]

not being in line with the knub on the flywheel was prob. your main problem. thats the whole reason i said buy a stock replacement.
good luck