Starts but immediately backfires and stalls

[speedyslyder]

looks like a vitos superstock piston.
make sure the ports on the cylinder have the proper chamfer to them next time also.
did you measure the bore before you bought piston?
you could get it bored ,honed/chamfered/oem base gasket/top end parts/torque it proper leaktest it,get a vacum plug on injecter nipple.not sure about your cases it will take awhile to get that rtv off lol

 

[jus_me]

I will add to above and to use only an oem cylinder also,, and not the Chinese crap on e bay/amazon.

 

[Awk08]

follow this for a perfect engine assembly............
http://www.blasterforum.com/threads/kor-engine-assembly-vids-no-crank-puller-needed.51169/

 

[speedyslyder]

if you want to take all the guessing out of it/and got the cash
ken will fix it the right way..he could also mod the head to for a huge jump in compression and hp...

http://www.kenoconnorracing.com/

 

[tbrooks]

There is no reason to go buy a cylinder, when you can get that one bored, and that piston looks way to loose in that bore, but maybe its just the light

 

[Blaaster]

I would be suspecting crap being forced back into the combustion chamber from the header pipe has scratched the piston.

 

[BlastrMastr240]

Is there any chance that piston would be usable in future builds or this build?

 

[Blaaster]

The piston would look good on the desk in the den as a pen holder!

 

[speedyslyder]

try selling that piston and see what happens

 

[Herpderplol]

i will pay shipping for it. my brother and i want to try some welding projects with them

 

[MercMenace]

The bike got messed up (broke a piston) when the crank seal failed (clutch side) and was exhausting through that case vent

Why did no one ask this?

When the last piston broke, did the bottom end get split and rebuilt? I bet you had garbage rattling in the bottom end that made it's way back up into the cylinder.

 

[BlastrMastr240]

Why did no one ask this?

When the last piston broke, did the bottom end get split and rebuilt? I bet you had garbage rattling in the bottom end that made it's way back up into the cylinder.

It did get rebuilt, once it blew the bike was IMMEDIATELY decommissioned and torn down. no bottom end damage was done. but as blaaster said... it may have come back in from the exhaust.

 

[MercMenace]

one tiny piece of a ring or a skirt can destroy a motor. there is no guarantee that metal doesn't make it into the bottom end. any time metal is broken free of the top end a bottom end rebuild is necessary IMO.