I just obtained a new Rossi 45. It's extremely tight. So tight in fact that at TDC I need to use a wrench to get the piston down again (I haven't reamed a prop for this engine yet). And that's without the glow plug installed...

None of my other ABC engines have been this tight new. Is this normal?

Thanks!

Being an ABC engine it can be that tight. If you put a prop on it you'll notice it's easier to turn over.

Some ABC's can be really tight although my Rossi wasn't quite that tight. However you should never turn over a new ABC slowly especially if it's only got the storage oil in it and no plug. Having the plug in lets the compression load the con rod so the piston doesn't go quite so far up the liner and then helps push the piston back down. Turning them slow just squeegees the oil of the liner (dare I say that castor will stay there longer??)

yes rossi's are ext tight. plug out turn lots with after run oil. make sure that the copper gasket supplied with engine is fitted. run engine with no more than 5% nitro 18/20%oil defnit caster be patient . great engine with great life when run in properly and cared for with lots of after run when not in use. a3 os plug also works great . dont use to much nitro is the rossi way!!!

Adrian,
can you tell me the best way to break in and tune a rossi 91 duct fan engine.

Yes, the Rossi's are tight when new. After 2 years of hard use, it still has really good compression. I've had my Jett 50 for over a year now and my Torqmaster 90, which has no problem with my Saito 91, still has a hard time turning it over. The Jett is still super tight.