OutdoorKing Repair Forum Forums General Discussion Forum Off Topics Scott Bonnar 45

Hi guys. I have a 17inch Scott Bonnar with Briggs 2.5 hp original motor pushing oil into the air filter and out. Does it need a new head gasket?if so is it worth repairing? I think the model no is 450520. If you think it's worth repairing the ,cylinder and backing plate need sharpening Where can I get this done. I live in Mona vale NSW

I'm guessing rings are a problem as you most likely have excess blow by. You could check compression but I'm not sure what spec you require. Check to see if the breather is not blocked. If not I would assume you would be getting oil out the breather as well. Best bet is the take the head off and inspect the bore. Hopefully no scratches otherwise you may be able to hone it out. If your mechanically minded put new rings with maybe a hone.

In these side valve Briggs engines, the crankcase breather is vented to the carburettor.

The valve tappet cover has a one way valve and some baffles in it, and a hose that connects it to the carby. It would be worth pulling the tappet cover and giving it a cleanout, but as drew2229au says, the most common cause of this problem is combustion gas blowby past worn or stuck piston rings.

It is probably not worth paying a shop to repair it, if it needs rings.
Replacement with a new engine may be the best option, in that case. A new Briggs 550 series OHV 3.5hp will be in the $300 ballpark, plus fitting.

Thanks guys will talk to outdoor King shop at Chiswick