fouling plug

[Melons]

Hi everyone, maybe you can help. I went out riding trails saturday for about 4 hours, bike ran great. Before I went changed the oil, new plug, gas mixed at 32:1.

I went out again on sunday and I had to add some oil to the case, it was somewhat low. I fouled the plug in the first 5 minutes, this was the same plug from the day before. So I changed the plug and this one fouls in about an hour of riding.

The plugs are wet and black. It doesn't smoke that much, just normal light blue smoke. Do you think trans oil is going into the cylinder and fouling the plugs? maybe past the rings. Bike really pulls hard and seems to have plenty of power. Do I need new rings and piston? Do I need to change the gas to 40:1?

I would be grateful for any help or insight one of you guys might have on this

thanks

[sweetass300ex]

did u take off the stator cover to see if u have oil in there could have a leak in the counter balancer bearing holder by the pick up

also did u change ur oil type and mixture that could have done it



sweetass300ex

[Melons]

I didn't pull the stator cover, not sure where it is. It may sound stupid but I have not taken one of these things apart before.

As for the oil, I used honda trans oil and honda mix for the gas.

This thing has not been ridin for about 5 years up till christmas time when i got it going again. Before that my ridin buddy took my bike and his bike in to shop for a rebuild and I don't remember what they did to it. That was about 10-12 years ago.

I can tell you that when I got it started a couple weeks ago it didn't have much power at high rpms. I changed the main jet from 158 to 150 and moved the needle to 5 position and it run great.

I did a search and found some info that there is a wet side of the motor and a dry side and if the wet seal in the motor leaks the oil can go into the chamber and foul the plug.

man I don't know. :huh

[Dave83]

Stator cover is on left side of motor.Says 'HONDA".When you say 5th position on the clip,you mean top or bottom?

[Melons]

bottom

[250R_4_ever]

well if you are adding Transmission oil ,there only 2 possibility
It's leaking or it burning

check if it's leaking first
then if it's not
change your oil seal on the clutch side make sure the crank sleeve it not to badly groove
If it dosent solve the problem It's probly sucking oil thru the Cases

Time for a rebuilt :devil:

BTW going from 158 to 150 main jet is pretty radical better make sure it's not to lean

[Lonestar_R]

yeah really look at the plug......you may think its black but it may be gray...I'd say its gonna need rebuilt.....

[Melons]

You think that 150 is to lean. When it had the 158 in it it would bogg at half throttle

[ckasper18]

Make sure your air filter is also clean if your using the hp2 honda pre mix 4 gallons of fue; to one bottle is 32/1 ratio.Call me crazy but if you warm bike up good and hold throttle wide open if it boggs down your rich if it sing a song keep going up a jet size till it boggs and then drop one jet size.Depending on what gas you are using its tough to read spark plug colors do to the crappy quality of fuels you buy at the pumps.Good luck with your quad otherwise take it to someone who knows what there talking about to have it fixed properly.

[Googs]

Originally posted by Melons
You think that 150 is to lean. When it had the 158 in it it would bogg at half throttle
You maybe still to rich. What kind of mods have been done to the bike?
I had a simular problem on my '85 R. I put a pipe on it and rejetted it, went from the stock 142 to a 152 (several "experts" suggested this). The bike would fall flat on its face in 5th gear at wide open throttle. I chased my tail for like 4 trips trying to figure this out. Finally rejetted it down to a 145, and the bike has been running like a champ for the last 2yrs.
Hopefully this will help.

[slick250]

Try replacing the crankshaft seal on the "wet" side. That is the side with the clutch. It is behind the crank gear. When you are in there, make sure there is no play in the bearing, as that would indicate a need for rebuild of the bottom end.