1995 Yz 250

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mikechristine29

Member

Jun 23, 2009

2

0

• Jun 24, 2009

• #1

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

 

F

FNG

Member

May 2, 2008

97

0

• Jun 24, 2009

• #2

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.

 

M

mikechristine29

Member

Jun 23, 2009

2

0

• Jun 24, 2009

• Thread starter
• #3

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

 

F

FNG

Member

May 2, 2008

97

0

• Jun 26, 2009

• #4

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.