Hello, basically I did the 18cc hemi head mod, porting from KOR videos, airbox lid off, 1mm exhaust port raise mod on an otherwise stock blaster. I installed 260 main and did the break in but after opening throttle I think I can hear loud pinging on higher rpm's and on top of that after I come to stop and put into neutral, the blaster shoots up in rpms like its an airleak, strange thing is that when I panic and turn the ignition key off, it still revs up and take 2-3 seconds to shut off( this doesnt happen if I havent been in high rpm's prior to stopping) . I did take a look at piston through exhaust port and I believe I can see scoring on the brand new vertex piston.
Specs of the mods
squish distance set at 0.86mm or 33 thousands
18 cc volume
0.05mm piston to cyl clearance
260 main
gutted stock pipe
no lid
european 98 octane fuel wich in usa equals to 93 ? \
premix at 32:1
engine has all new gaskets and oil seals
200 feet elevation, outside temp minus 5 celsius or 23 farenheit
compression at 160 psi
If more info needed ill try my best
thanks in advance
Specs of the mods
squish distance set at 0.86mm or 33 thousands
18 cc volume
0.05mm piston to cyl clearance
260 main
gutted stock pipe
no lid
european 98 octane fuel wich in usa equals to 93 ? \
premix at 32:1
engine has all new gaskets and oil seals
200 feet elevation, outside temp minus 5 celsius or 23 farenheit
compression at 160 psi
If more info needed ill try my best
thanks in advance
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