Two Stroke Question

[cello]

Following on from my previous threads - HAd my barrel re-plated as the machine was 6 years old , rebuilt with new piston , ran in fine for 2 hours - then motor seized .

Stripped down the motoer and it was obvious the plating had failed , big flakes of plating missing .

Plating company recoated the barrel @ no charge but on fitting the powervalve it is apparent that when they welded up the damage they had managed to weld up the groves where the powervalve sits . Having sat down for two hours with a file and recut the grooves the power valve fails to drop/close down completely - the Question is WHAT EFFECT WILL THIS HAVE TO THE MOTOR ?

I am concerned about overheating issues as I am aware that there may be slight loss of power at the bottom end with a step in the powerband rather then a nice linear curve of torque / power .

Anybody have any advice ?

 

[MX145]

SEND IT BACK !!

 

[marcusgunby]

I adgree with mx145, who did yours as im thinking of sending one out and dont want this kind of problem.

 

[cello]

A company in the UK called Aptec / Poeton , they have offered support since the plating failure but I have been off the dirt for two months and am currently rebuiling my bike for the secondtime with the original piston - the labour for all the work is cuurently @ 10 hrs - good job I,m not contracting this out out to someone . Oh yeah also down £130 as my new piston is completly U/S .

 

[penguin]

did you send along the piston when you had the cyclinder replated? If the piston and cylinder were not matched, the piston could expand faster than the cylinder and cause much grief. just wondering.

 

[Zenith]

Marcus,
Langcourt in Wales did a reweld and replate for me about a year ago. It seemed like a good neat job, certainly no problems like cello had with the valves. Of course the cylinder failed within about 2 hours of riding, another snagged ring. Could be we missed some dirt in the intake somewhere or bad job, who knows. We just bought a new cylinder after that, it was under twice the price but worth it for the peace of mind...

 

[marcusgunby]

problem is i have this ported EG133 kit that needs welding and plating and i dont want to send it to someone who will not do a good job.It seems a shame to waste such a work of art.

 

[cello]

New Piston was sent with the barrel - Having built the bike and having started it it is apparent that there is prenounced Tapping noise .

Believe this to be the old piston slapping round a bit in the bore or the little end ( new - but used @ the time of faliure ) .