What does a very wet, very grey plug mean? not white or ash. Exactlymlike someone dipped the whole tip in primer paint and it is still wet. The top of the cylinder is very black and very shiny. I have been working on my 2001 mountain max700 Trying to jet it all season long. I have been having no luck at all. I am wondering what a coolant leak into a cylinder looks like? It is the center cylinder. The other two are jetted the same 132.3 they look normal. I ride at 10,000ft, I have tripple pipes. pilots are 62.5. needle 3rd e clip one up one down Stock. Compression 90 psi
I am looking for some outside opinions. I will try and post pics soon. So I made some mods. Handlebar riser,removed 1 head gasket layer. Drilled the air box. I jetted rich 138.? The machine has run poorly all season. Backfiring, ( not the loud violent kind, just like the engine sighs and coughs) the plugs have been difficult to read. For a while the machine would not run long enough to get a plug reading, or foul the plugs so bad they stopped working. I was running way rich, I have been leaning it up as I go, one size each trip, but still not right. The grey has me worried, but the cylinder being very wet and very black top throws me for a loop. Help would be appreciated. Thanks
I am looking for some outside opinions. I will try and post pics soon. So I made some mods. Handlebar riser,removed 1 head gasket layer. Drilled the air box. I jetted rich 138.? The machine has run poorly all season. Backfiring, ( not the loud violent kind, just like the engine sighs and coughs) the plugs have been difficult to read. For a while the machine would not run long enough to get a plug reading, or foul the plugs so bad they stopped working. I was running way rich, I have been leaning it up as I go, one size each trip, but still not right. The grey has me worried, but the cylinder being very wet and very black top throws me for a loop. Help would be appreciated. Thanks
A couple of bucks
VIP Member
You have a head gasket leak. No doubt about it.
A couple of bucks
VIP Member
When I did our head gasket mods, I High Tacked the center and the outsides. Then did a two stage torque on the head bolts/nuts.
Well, I could have had a coolant leak, but now I have a scored cylinder w a broken skirt. Mystery is the broken skirt is gone. Gone gone. No pieces I the case, small piece in the exhaust. It was one side of the skirt. Where did it go?
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I am trying to post pics
sleddineinar
VIP Member
That's what I think happened to my sled this year. I fouled my mag side plug, but when looked it also had a slight grey look to it. I thought maybe it was lean, so I jetted it up a size. Went for a ride, blew 3 holes in my case when rest of the piston let go. When I increased the jets I figured I was getting some material from the top edge of the piston, that's why there was some grey. I was also getting some backfiring like you described, not hard, but like it was sneezing.