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New SIL GP200 motor question
Posted: Tue Apr 20, 2010 12:40 am
by lammie200
I am working on stuffing a stock off-the-shelf SIL GP200 motor into a Series III frame.
When checking the motor over before I install it I fond that the piston only has the top ring in place and the grooves for the lower two rings are very shallow. I haven't pulled the clylinder, so I was only looking through the exhaust port. Do these engines usually one come with one ring? The motor itself was probably manufactured 7-8 years ago. I bought it off someone that never used it. I am very sure that it has never been run or cracked open.
Re: New SIL GP200 motor question
Posted: Tue Apr 20, 2010 12:54 am
by shocky
lammie200 wrote:I am working on stuffing a stock off-the-shelf SIL GP200 motor into a Series III frame.
When checking the motor over before I install it I fond that the piston only has the top ring in place and the grooves for the lower two rings are very shallow. I haven't pulled the clylinder, so I was only looking through the exhaust port. Do these engines usually one come with one ring? The motor itself was probably manufactured 7-8 years ago. I bought it off someone that never used it. I am very sure that it has never been run or cracked open.
no ive run them with the top ring removed though as some pistons had a cast ring at the top and 2 chrome rings on the next two groves
Re: New SIL GP200 motor question
Posted: Tue Apr 20, 2010 10:14 am
by paul213
Steve I dont want to upset you but the info I found said 2 chrome rings in the top 2 grooves and the plain cast in the lower it is quite common to leave the plain one out on tuned motors .
from scooter restoration site
http://www.scooterrestorations.com/lamb ... 4mm-mahle/
did you have the piston upside down.
Paul
Re: New SIL GP200 motor question
Posted: Tue Apr 20, 2010 11:30 am
by shocky
sorry thats what i ment
Re: New SIL GP200 motor question
Posted: Tue Apr 20, 2010 3:38 pm
by corrado
lammie200 wrote: I am very sure that it has never been run or cracked open.
It will have been run as SIL bench test them. If there's no signs of it ever being run, ie marks on the piston and thick gunge that passes for gearbox oil in India, then it's possibly a back street Injun motor, so worth checking out all the internals too.
Re: New SIL GP200 motor question
Posted: Tue Apr 20, 2010 7:51 pm
by lammie200
I was planning on rebuilding everything except the top end for this first pass. Now it looks like I will need to do that as well.
I will know more about if it had been bench tested once I pull the head. It may not have been though because from what I can see of the piston it looks pretty clean.
It may be some backwoods build, but I don't think so. It had undisturbed SIL yellow tape on the intake and also on the stator wires that were taped to the flywheel shroud.
Bottom line is that it is just more work and money for me. Nothing that I haven't done before on these bloody machines.