[michael4012]

A plug broke in my +3mm build I'm not sure why after 1500 miles if it was a million in one fault or heat damage (engine never registered above normal temps) but the puzzle is the head gasket (cometic 0.018 X 79me) has broken or burned through between the 4 (damaged piston) & 3 cylinders thankfully no head or valve damage but I'd like to know why it happened so hopefully I can prevent it happening again.

 

[gazx10]

plug appears burned off, headgasket is burned thru, that's exactley where most pistons burn away from detonation. dont see any signs of mechanical damage in pics. all 3 of these are strong indicators of detonation. get ur injectors flowed/tested. suspect a faulty injector/fueling problem on that cyl if running stk ignition timing. make sure tune spot on.

 

[badassjake]

yup^^^^

 

[Ryan66]

Would like to add some info but its already been said. Detonation for sure. Too much cylinder pressure and not enough octane broke the plug. What octane were u running?

 

[michael4012]

Thanks for the input Iv taken it onboard, the injector is most likely Iv got another set to put in ignition is at +2% & the pump fuel over here is 97 Ron. I wouldn't mind finding out about after market head bolts to get more torque down. So it's start RE-build time I'm hoping Wossner can match a piston otherwise it's a set off 4 ?

 

[gazx10]

nothing wrong with the hg u were running, pics clearley indicate adequate pth and compression not the issue with 97 ron. pull the timing, maybe even retard a degree. think u will find the bike even faster, been my experience. got to the point i have injectors professionally cleaned/flowed on all my builds along with a hi flow fuel pump after too many fueling issues on the dyno. good insurance, makes for solid hp and reliability. stk. head studs will hold all tuning factors corrected.

 

[SpazOnaZX]

YUP. That missing section of piston right there is the first thing to go if you detonate/melt a chamber.... it gets worse from left to right on these motors (as you get closer to the timing chain).... take a good hard look at the other pistons around the valve relief area; any deformation and/or lifting will show that it's an overall tune problem. If the rest are perfect you may have a bad single injector like Gaz stated. Have those guys cleaned/flow checked!

 

[michael4012]

Spot on guys three pistons are unmarked its just the 1 its defo an injector problem, the bummer is i just been told wossner dont have a match for that set i gotta buy 4 off em :angryfire: i just put the stock engine in her tonight so i can still ride while i re-build this fucker thanks all for your help :notworthy: