I Keep Fouling My Plugs???? - Snowmobile Forum: Your #1 Snowmobile Forum

RIPPER GMC · 11-20-2007, 12:35 AM

I have a 98 Polaris 680 ultra with PSI pipes and keep fouling plugs. I rode at Petersvile this sunday and I fouled 3 plugs...CAN ANYONE HELP!!!!

shift · 11-20-2007, 12:36 AM

Quote:

Originally Posted by RIPPER GMC

I have a 98 Polaris 680 ultra with PSI pipes and keep fouling plugs. I rode at Petersvile this sunday and I fouled 3 plugs...CAN ANYONE HELP!!!!

Sounds like your too rich. Either lean it up a bit or crack her wide open more, get that carbon out of her.

RIPPER GMC · 11-20-2007, 12:54 AM

Ohh she's wide open most of the time, when you say too rich do you mean too much oil and not enough gas or reverse. I actually seems to happen while I'm ripping up a powder field or right after

shift · 11-20-2007, 12:55 AM

Quote:

Originally Posted by RIPPER GMC

Ohh she's wide open most of the time, when you say too rich do you mean too much oil and not enough gas or reverse. I actually seems to happen while I'm ripping up a powder field or right after

yeah too much unburnt oil is covering your plug and its not getting enough spark. Your rich. Start leaning down your main jets and play with your air screw a little bit

RIPPER GMC · 11-20-2007, 01:00 AM

OK I'll give it a try, do you think a hotter plug would be better also..I;m running BR9ES's right now

shift · 11-20-2007, 01:02 AM

Quote:

Originally Posted by RIPPER GMC

OK I'll give it a try, do you think a hotter plug would be better also..I;m running BR9ES's right now

Doing that would be a band aid fix. You should really just take the time and find out the best jets and just expirement until you get whats right for your machine, its better in the long run.

WolfOne · 11-20-2007, 02:54 AM

I don't know if can help you but 2 years ago I had the same problem with my RMK 800 when I rode slow

the problem was a broken wire of the mix-pump cable that made unable the mix-pump to return in low position when I leave throttle

at low rpm I was always rich

**RJ Gleason** · 11-20-2007, 02:55 AM

Make sure that the chokes are not stuck partly open too.

**smallengineguy** · 11-20-2007, 06:53 AM

Go down no more thatn one size at a time on the main jets when you do change them.

RIPPER GMC · 11-21-2007, 05:35 AM

Alright thanks alot for all the info, I put the stock pipe back on and I'm going to try and find a place to test it tommorrow.

BC_Dan · 11-21-2007, 11:15 AM

There are two ways to foul a plug... you can be too rich on the jetting and foul a plug, or adding too much oil and foul a plug. If it's oil fouling, changing the jetting won't get rid of the fouling. If the plugs are wet/black when you are fouling, I would suspect oil fouling, and look at the oil pump. Make sure it's adjusted correctly and is not delivering too much oil. If the plugs are dry and black, then work on your jetting.

And like SEG said... only go one size in the jetting before you test, it doesn't take much to go from too rich to too lean, and too lean will burn hot enough to melt holes in your pistons...

RIPPER GMC · 11-22-2007, 03:43 PM

Thanks, it seems to be oil fouling but the pump is adjusted correctly, maybe I will make it premix, I also took off the PSI pipes and put the stock pipe back on, then downsized the jets 3 sizes total.