2002 Suzuki RM 250

**Sebo** · 05-26-2008, 11:40 AM

This bike was bought used about two years ago. The top end wsa changed about 5 hours ago. However, the bike keeps fouling plugs. I am running the bike at 40:1 and i was previously running it at 32:1. The bike works fine on new plugs but once they get fouled with oil, it does not want to start up. So i have to use several new plugs each day i ride. Have you guys had any problems similar to this. Any help would be appreciated. I wanna get this bike running perfectly for the new season

23 · 05-26-2008, 11:43 AM

Originally Posted by Sebo

This bike was bought used about two years ago. The top end wsa changed about 5 hours ago. However, the bike keeps fouling plugs. I am running the bike at 40:1 and i was previously running it at 32:1. The bike works fine on new plugs but once they get fouled with oil, it does not want to start up. So i have to use several new plugs each day i ride. Have you guys had any problems similar to this. Any help would be appreciated. I wanna get this bike running perfectly for the new season

Why are you running the bike at 40:1 ?

**Sebo** · 05-26-2008, 11:44 AM

well it was fouling plugs at 32:1 so i figured i would make the ratio leaner. Clearly that did not help

23 · 05-26-2008, 11:46 AM

Originally Posted by Sebo

well it was fouling plugs at 32:1 so i figured i would make the ratio leaner. Clearly that did not help

Im no pro mechanic but im thinking your jetting is off, have you torn down the carb yet?

Do you know what needle is in it?

**Sebo** · 05-26-2008, 11:55 AM

i actually just recently spoke to a mechanic on another site and he told me its the jetting as well. Since i have two people thinking the same now, i guess im gonna have to go into the carbs now.
I gave him all my information such as altitude and temp in the area and he gave me the specs (jetting) that i should use :
run a 165 main, 48 pilot, and drop the needle from the 3rd clip to the 2nd clip.

I think the jetting is still the same way it came stock.

**sourandmouldy** · 07-31-2008, 03:29 PM

I had the exact same thing happening with my 97 RM250 after a new top end, it would run great until I had to re-start it. I switched to hotter spark plug (From a 9 to an

and it completely fixed the problem, never fouled another plug again.

Hope that helps

Sam

**sourandmouldy** · 07-31-2008, 03:30 PM

Sorry that smiley face is an eight...don't know where it came from!!!

8

**inreb** · 08-04-2008, 04:08 PM

Originally Posted by sourandmouldy

I had the exact same thing happening with my 97 RM250 after a new top end, it would run great until I had to re-start it. I switched to hotter spark plug (From a 9 to an

and it completely fixed the problem, never fouled another plug again.

Hope that helps

Sam

just be advised that not all plugs go to hotter on a lower #, of course I forgot which is which (it's been a while). check it out.