1995 Yz 250

[mikechristine29]

i have a 95 yz 250 just had the top end bored .080 over my main jet was a 180 at .040 over what should i change my jet too? plugs a grey color when i pull it out and when it cools down it turns to a grayish-black. i was running it at 50:1 but changed to 40:1

 

[FNG]

I have a stock bore 1995 with a RAD valve and I run a 170 main in MN @ 900ft elevation. I run 32-1 mixing 30% 110 octane with 92 oxy.

Seems to like it, good plug color and wash on the dome.

.040 more will not require a change in jetting IMO.

 

[mikechristine29]

i also noticed that it runs pretty hot even if im only on it for a couple minutes. do these things run really hot. and how would i know if the water pump isnt working

 

[FNG]

Your water pump drive gear may be toast. It is not easy to see and harder to replace. Mine was veryworn out and missing many teeth.

Mine ran hot until I replaced it. Now it is much cooler running and seems to run like it should temp wise.