Odd spark plug boot issue

[rbblrsn]

Great day of powder riding last week, for over 3 hours my 2006 M800bb ran perfect in a mix of hard and easy running, small jumps, tight turns and boondocking in awesome snow. Then while riding calmly and straight at only about 30 mph across a dead flat meadow the sled sputters and dies. Wont start, no firing at all. So I pop the hood to investigate and find that BOTH spark plug boots are off!

The only thing I could think of is that under-hood heat finally softened the rubber enough to let 'em loose, but there was no moguls or rough conditions to bounce 'em off, nothing but dead smooth powder. Maybe some vapors ignited under the boots, or ???

Popped boots back on the plugs, started on first pull, not another problem during the next 20 miles.

It was strange. I might zip tie 'em on for the next ride... or maybe shield with heat tape...Anyone else seen this?

(This on a 2006 with only one plug per cyl.)

 

[offroadmatt]

My 07 m8 was doing this last year couldn't tell till you stopped and let it idle. You could hear the plug wire arching out on the head making a ticking sound. Went to the dealer bought a new boot around $5 if I remember right haven't had a problem yet. Carry a spare boot now so I don't have to worry about it on the trail.

 

[rbblrsn]

The boots weren't just loose, they were both completely off the plugs and tucked into the gap behind the heads. THey had to have blown off. Maybe when the rubber softens it gives off volatile vapor that is ignited by the spark? Dont know for sure,sort of a mystery.

Zip ties from here on out.