A Different Saga

[mswyka]

Good morning.  Yesterday I had the benefit of getting out with a friend who owns a pair of Skidoos - a 500 Blizzard and a 370 Saga.  He is telling me that the Saga keeps fouling plugs and, the couple of times that I have ridden with him support this contention.  The sled is good for an hour or so and then will quit.  A fresh set of plugs and it is on its way again.  I have no Skidoo knowledge and am hoping that someone here will have some suggestions.

[gixxer6]

I would start by checking the jetting and doing a compression test. 

[mswyka]

I would start by checking the jetting and doing a compression test.

When you say checking the jetting, my guess is that the sled likely has the original jets.  But we will need to pull the carburetor apart to be sure.  I will have to remember to take the compression tester the next time we head to the mountains.

[Boomologist]

Don't know much about sega but I would see if it's overheating.

[mswyka]

Don't know much about sega but I would see if it's overheating.

What temperature would you consider too hot and at what location?

My limited observations suggest it is not overheating, but I have not hit it with a thermometer.  Now I have two tools that i have to remember to take with me next trip.

[rminier]

Just suggestions of what I would try:
 Are the spark plug caps still the metal style that SkiDoo used for years? They have proven troublesome after many years....replacing with some new NGK caps has been a common practice for lots of us SkiDoo owners when encountering spark issues....plus you would trim the spark plug cables back 1/4" to get to fresh wire in the cable.
 Proper spark plug, with proper heat range, CHECK the gap, etc. ?
 Is it premix or injected? Using decent oil and injection set correctly?.....might try one heat range hotter plug.
 Probably running rich fuel/air mix....were outside air temps rather warm, or does it foul plugs on very cold days also?
 Probably jetted rich from the factory..??....try dropping the jet needle down one position....unless spark plugs look too light in color.
   How do plugs look when removed?? Really dark? always the same side?
Fresh gas in the tank? What are the chances there is some water in the gas tank?
 Does it have an enrichener (choke) on the carb? If so, that plunger has to fully seat in the carb body or it will run rich.
 Observe primer tubing.....can you see fuel being drawn through primer when engine is running?....if so, time for a new primer.

[Boomologist]

Just re-read your post and agree with "rminier". Probably not heating up.

[mswyka]

Good suggestions.  Thank you.

[mswyka]

Had a chance to spend a little time with the Saga today.  Compression 150 on each cylinder.  Spark Plug caps are NGK.  Plugs are BR9EYA.  Forgot to check the primer and enrichener.  Fouled two sets of plugs today dark black.  I don't think it is over oiling since it does not make much smoke.