I rebuilt my 1989 KX250 and it runs good except after each my spark plug is usually toast. I can ride all day long, but when I get the bike out next weekend it'll fire up and while running (choke on or off) it will start to go "Burb burb burb.." and die out only to have an oil fouled plug.
I have standard bore, fresh rings, crank seals, bottom + top end, but have some old reed valves, unknown carb jetting, and an old, but clean air filter. Oh, and I run Yamalube premix at 32:1.
The bike has always run good, but won't keep a plug in it.
Last week I changed to Klotz premix at 40:1 with a fresh B8ES and it ran good for about an hour before developing a stumble. When I get out on the straights I would nail it and the bike would drag like the plug was fouling.....blip the throttle a couple times and it clears out and pulls good. I rode like this for a couple hours with it wanting to foul (or so it felt) but it would clean back up?!?! Before...when it would start to act fouled...it would die soon with no restarting.
Does this sound like a familiar problem? I don't want to replace anything unnecessary.
The bike also had a weird surging problem where the idle would slowly raise up and if you blip the throttle it would go back down. I was told it was an airleak, so I tightened the carb boots and it seemed to take care of it only temporarily before acting up again. Could this be contributing to my plug issue?
Any suggestions would be welcomed.
Micah
I have standard bore, fresh rings, crank seals, bottom + top end, but have some old reed valves, unknown carb jetting, and an old, but clean air filter. Oh, and I run Yamalube premix at 32:1.
The bike has always run good, but won't keep a plug in it.
Last week I changed to Klotz premix at 40:1 with a fresh B8ES and it ran good for about an hour before developing a stumble. When I get out on the straights I would nail it and the bike would drag like the plug was fouling.....blip the throttle a couple times and it clears out and pulls good. I rode like this for a couple hours with it wanting to foul (or so it felt) but it would clean back up?!?! Before...when it would start to act fouled...it would die soon with no restarting.
Does this sound like a familiar problem? I don't want to replace anything unnecessary.
The bike also had a weird surging problem where the idle would slowly raise up and if you blip the throttle it would go back down. I was told it was an airleak, so I tightened the carb boots and it seemed to take care of it only temporarily before acting up again. Could this be contributing to my plug issue?
Any suggestions would be welcomed.
Micah