Loss of compression

[barryh]

I can't remember whether it was here or else where but we talked of valve seat recession being temperature dependent which means higher ambient temperatures and sustained high speed running and exhaust valve more than inlet valve will be when it tends to occur the most.

Not to put a damper on your good experience so far but you might not expect to see any recession in cold weather and moderate use.

[Rob Frankham]

I don't think we'll ever know all of the pros and cons of VSR. Even at my most optimistic, I can't see a great deal of research being done into it. It is, virtually by definition, 'a disappearing problem'. As old 'lead dependant' engines (and now IC engines in general) become fewer in number, there is no will or profit to be made investigating it further. There is also so much contradictory and often ill informed information on the web that a definitive answer simply isn't available. My reading of the situation is that it is so variable, inconsistent and complex that the only ways forward are to:

A) get a newer engine (or bike)
B) Get the heads modified,
C) Use an additive (which seems to be effective but inconvenient)
D) Monitor the situation and if it doesn't happen, well and good... if it does then it's back to A,B and C.

Rob

[1991 R80RT]

Sounds obvious I know, but when you check your head torque, don't forget to loosen the nut an eighth of a turn before re-torquing as 'stiction' will fool you into thinking all is well when it isn't.