11 M8 Fouling Plugs

[estaked]

I have been having an issue on and off this season with the back plugs fouling. Took it into the shop and they are not sure why it keeps happening. Happens especially if the sled has sat overnight outside, fire it up in the morning it will back fire. Replace the back plugs and will fire right up. If it stays inside wont have an issue starting the next day.

It's a 11 M8 162 standard, has an SLP can, some clutching done, and Frog skin vents. Little over 1300 miles.

Thanks for reading and any help is appreciated!

 

[estaked]

Dang no one? Ran cleaner through it (seafoam) still did it on Friday, backfired. Back two plugs were dark and wet, replaced and fired right up. Sled runs great when those plugs don't foul. I have good compression.

 

[sledhead685]

What do the front two plugs look like? Are they soaked in gas or oil? The oil pump on my 09 was sticking open and really gumming up the plugs, but all 4 plugs looked the same.

 

[Hardass]

You say it's happening after it's left outside i wonder if it could be getting moisture some how. It's odd to me that both back plugs would do this at the same time. I would look for the common thing that those 2 plugs,plug wires or coils have in common

 

[Thunder101]

Well there is four coils and only the back plugs are wet. I would check oil consumption, but Im betting on high fuel pressure.

 

[estaked]

Oil consumption seems to be fine, I will pull the front plugs and give them a look. It didn't do it over the weekend after sitting out Friday and Saturday night so, the outside thing must of been a coincidence.