Noob with spark plug questions - Snowmobile Forum: Your #1 Snowmobile Forum

vdubplate · 11-19-2012, 04:51 PM

Hey guys, I bought my first snowmobile the other day. I got an 07 Skidoo Summit. I haven't been able to determine which version of the Summit I have but I know I have one. I got it home and started to inspect. I probably should have done this when I was buying but I didn't. In fact I wasn't sure what to look for. So I had a few questions. I did a compression test and bost sides are at 115. Is this considered decent? Also the plugs are fouled as seen in number 2 here: Spark Plugs
Since have no idea what caused this I wanted to put new plugs in and see if its a choking issue or something worse. Any ideas? The sled has less than 800 miles on it.

**BC_Dan** · 11-19-2012, 05:38 PM

Oil fouled spark plugs are pretty normal for 2-stroke engines, especially snowmobiles that get run for a bit then shut off during the summer months. You will find most guys change the plugs at least once a year, and always carry spares.

115 compression is not too bad, anything above 100 will run the engine. As long as the engine starts easily and has adequate power, I wouldn't be too concerned. With less than 120 compression, the rings may be showing a bit of wear, but not bad enough to require replacement.

vdubplate · 11-19-2012, 05:47 PM

Phewww, Thanks for the response BC_Dan, The engine starts on first or second pull. That lets me rest easy. After reading that chart I was thinking I was doomed to have to do some engine overhauling and I'm not ready to drop that loot just yet. I'll switch those plugs out and see how the sled runs this winter. It reads less than 800 miles. Hopefully thats correct.

**BC_Dan** · 11-19-2012, 09:57 PM

If it's 800 miles, you are at least a couple of thousand before you need to worry about new pistons/rings. Congrats on the new ride!