Kind of an odd question - Snowmobile Forum: Your #1 Snowmobile Forum

illwerral · 01-23-2006, 04:03 PM

So today I went for a ride, rode kind of hard, had a good time. About half an hour or so after the ride I went out to start the sled up. It would fire a little bit and sputter a bit and die. So I changed one plug, which had a weaker spark than the other and it fired up and idled nice. I took it for a little spin and it accelerated really nice compared to before. Now I shouldn't be complaining about my sled running well, but it worries me because the last time I did a compression test both cylinders were around 100psi. It normally bogs. I have no clue why it would be so hard to start, and then it would start up and run better than before. My spark plugs are generally dark, and not really brown. This is what they look like now:

illwerral · 01-23-2006, 04:03 PM

Second

illwerral · 01-23-2006, 04:04 PM

And another, since I used three spark plugs (changed one out and left the other)

illwerral · 01-23-2006, 04:05 PM

The pictures aren't the best but they show the color reasonably well. Before I changed a plug and went for a second ride, both plugs looked more like the first, kind of a golden brown.

SnowRida · 01-23-2006, 04:14 PM

Did you really ask a question?

Goldeneyes · 01-23-2006, 04:16 PM

100PSI on both cylinders would most certainly contribute to hard starting and poor performance. You should have around 120PSI

illwerral · 01-23-2006, 04:42 PM

Quote:

Originally posted by SnowRida
Did you really ask a question?

Yeah I did. I was asking if anyone knows why it would all of sudden not want to start, and then when it did start run better than before. Like usually it starts one to two pulls, idles low and bogs until 5000-5500 rpm. After I got it started again it kept its idle at around 2000 instead of 1500, which was odd. When I started riding instead of bogging it just went. Best acceleration I can remember out of the thing. Putting in new plugs has never helped that much before. Instead of a dark color the plugs were more a golden brown.

SnowRida · 01-23-2006, 04:46 PM

Still, if it starts hard, I wonder if your compression is on the low end. Are you running iridium plugs now?

illwerral · 01-23-2006, 04:52 PM

I've tried the iridium plugs, and once I rebuild my engine I plan on using them again. When I said that there's 100 psi in each cylinder, I was saying that it worries me that it would run well. Because I know that's low compression. That's why I'm asking why it might all of a sudden start running significantly better. Sorry for not being more clear in the first place, long day today so I'm kinda tired and not thinking the best...

ITriumph · 01-23-2006, 04:55 PM

Judging by the color of the plugs, it looks like they're burning ok. 100psi isn't the best compression, but not the worst. What are the outside temps like? Your sled is jetted for a certain temp range, and it is possible that you were outside that range, but then again your plugs would show that. there's also the possiblity that there's water in your gas.

illwerral · 01-23-2006, 04:59 PM

It was kind of warm today, around -5*C. But my sled is fuel injected so it takes care of the jetting automatically as far as I know. Now that you mention it I've been forgetting to put gas line antifreeze in and it was sitting at around a quarter tank for a couple days until I filled up today. I guess the water could cause the hard start, but I don't get how that would make it run better than normal once I got it started?

letitsnow · 01-23-2006, 05:51 PM

it might have been the lack of drygas that made it run better.

ITriumph · 01-23-2006, 08:34 PM

what happens is condensation builds inside the tank, and drips down the edges of the tank causing water bubbles in the gas. I'm sure you ride your sled alot, so it won't beable to totally separate. Look at your fuel lines (if clear). See if there are bubbles in it.

illwerral · 01-23-2006, 09:11 PM

I'll check that out tommorrow. Thanks for the replies!