Scooterotica

Thought I'd float this baby !!

Just built a fresh engine. Its a GP 200 indian engine, so I have replaced with all new bearings and seals.....only difference being I have replaced the original 3 ringed piston with a new 2 ringed piston found sitting in me shed. The barrel is non standard, but is a steel barrel with with aluminium fins, (not sure what it is, but like a rapido I guess, although the steel inlet and outlet is poorly cut out to match the outer alloy lining but probably acceptable). Squish is 1.3mms and it has a Jetex 22mm carb.

Put engine back in scoot and it has a squeak a bit like you'd get if the head gasket had a slight leak and the engine is racing a little on idle and whatever I do to the carb to bring it down it has little effect (so thinking air leak). I changed the head gasket but this time added a little sealant to either sides of the head gasket faces. Put bike back together on scoot and it still does it. Wondering if it could be the mag side gasket or even base gasket but no obvious oil leakage.

Any ideas ?

Oh and it's not a mouse in there......I checked lol

Try spraying some wd40 round the inlet manifold, base and mag and see if it settles temporarily.

Or do a search for leak down test, lots of suggestions on how to do it.

Ross thanks read the leak down test posts. I will try that and also changing the piston back to the original, but I understand someone called Darryl on here sells leak down test kits ? or does anyone know where I can source one ?

I had an annoying squeak when I ran a Jetex some while back- same as you i couldn't find it. I then changed the slide to another one and noise disappeared- edge of old slide had an "edge".

Worth swapping before you do anything major.

Chris

Bristolmod, I did wonder if it was the Jetex but it still squeaks with the carb off....

Strummer10 wrote:Bristolmod, I did wonder if it was the Jetex but it still squeaks with the carb off....

probably goes better with the jetex off as well!

sounds like head leaking.

I leak tested 2 engines recently and found air leaks on both. both leaks were around the base of the barrel studs, between the stud and the spigot hole. It's only a thin area there so could be prone to leaks. The leaks showed up by travelling up the stud hole in the barrel and exiting out of and around the cylinder head nuts.

Cheers Guys........ha Bristolmod (man after meself) on the Jetex, I think there dodgy too lol. Mick I guess I could just whack some sealant on both faces of the base gasket and maybe a little on the bottom ends of the cylinder studs. I will also do the same to head gasket and maybe just rub the cylinder head and barrel down a little on some fine emery paper..........wouldn't mind but just built 2 other engines with no issues at all........