TRFTIM

I have just ran my Nova Mega today and unfortunatley it blew 2 plugs and at the end I seem to not be able to turn the piston over at TDC, the piston runs cleanly in the sleeve, but at the top it is very dificult to turn over.

The piston has obviously had something tapping against it has pitting marks, which probably why the glowplugs went.

Not too sure if I need a new piston and liner though??

Anything else it could be??

Thanks

Tim

Jamie Corrado

iTrader: (17)

Tim,
Sounds like your high end needle was set extremely lean. Pitting on the top of the piston and bottom of head button with the loss of 2 plugs is usually a good sign of this.(detonation)
If the glow plug wire didn't score up the sleeve and sides of the piston you can just polish the metal smooth again with some JP polish.

Hope this helps.

TRFTIM

Hi Jamie

Thanks for the response!!

I think the piston is ok along with the sleeve its just the button and the top of the piston that pitted, I also think that the motor got too hot due to me not putting enough holes in the bodyshell

With regards to the tight fitting at TDC is this normal as it wasnt like this before.

I hope its an easy affair taking the engine out of a Serpent 705.

Thanks Again Jamie

Ps you wouldnt know per chance if I need Turbo plugs in it?
UPDATE

Just taken the rear cover off and it looks as if the brass bushing that is inserted into the conrod has broken into pieces!! Can I buy just this piece or do I need a new conrod??