How to replace rings on Linhai 257cc By jenningsjosh (Read 3,605 times)

[jenningsjosh]

here is rings again different view with them lined up



(under) here they are compressed

[jenningsjosh]

There is an air leak at exhaust.. 100% sure.. and its a lot of air... i hooked the exhaust back up.. tight as i could get it... blew into exhaust pipe with all other outlets closed off... and i can feel and hear air coming out around the exhaust

[Alleyoop]

Not a problem just get a new Exhaust gasket, lots of time the nuts come loose on them and when your riding them and you will notice the different sound due to it leaking. If it leaks bad enough it will backfire usually when you let go of the throttle.
Alleyoop

[vansmack2]

You check the ring gap by taking them off the piston, and push them down into the cylinder then measure the gap. The ring should be parallel to the top of the cylinder when you measure the gap. I have included a picture of someone checking the ring gap, and the specs for a Yamaha YP250.

[jenningsjosh]

i used the piston itself to push ring into correct position... .008 inches.. or .20 mm

both same

[jenningsjosh]

I am ordering rings..gaskets.. belt.. www.scooterparts4less.com/260cc_Motor_Parts.htm and exhaust gasket... www.scooterparts4less.com/web_gas/4Stroke_exhaust_gasket.htm

The majority of what i have found is 69mm rings... i will slap calipers on it tomm and post pic... gonna go with 856-23-30 belt.... not sure on size of exhaust gasket to order but gonna have it measured as well...

[Alleyoop]

Great, you know you where loosing compression due to the rings , they may be weak and not spreading out enough to seal since putting oil rose the compression back to 200 psi.
Alleyoop

[vansmack2]

Aug 31, 2013 22:07:22 GMT -6 jenningsjosh said:

i used the piston itself to push ring into correct position... .008 inches.. or .20 mm

both same

According to your measurements posted your ring end gap is well within specs. That looks like a .009 inch feeler gauge in the pic, but even at .009 that is just under 23 mm.

Did you check top ring, 2nd ring, and the oil ring? You also need to check the ring side clearance. That is the clearance between the ring when installed and the piston groove.

One thing you don't want is you ring gaps being close to each other like yours are in your picture. You should stagger them around the piston so as to reduce the chances of oil leaking by them.

[jenningsjosh]

It is .08.. but anyways.. I am gonna order new rings.. they are 20 bux.. might as well.. plus I destroyed the gaskets while takin it apart...

[jenningsjosh]

I have lost one of my clips during the process of taking the piston off... think i can pick one up at auto store? or anyone know where i can order one CHEAP... or maybe someone knows where I can order rings that contain the clips as a package... I wanna get this crap ordered and put it back together

[Alleyoop]

Come on Bro tell the truth How could you have lost a clip. You bent the heck out of it didn't you??
Alleyoop

Ever heard of google?
www.2wheelpros.com/oem-parts/honda-power-equipment-clip-piston-pin-13115-283-000-part.html?gclid=CL7uysHWsLkCFUhgMgodOUwAIg

[jenningsjosh]

When i pulled it out.. It shot like a bullet.. I think it might have went into the oil resivor.. there is the truth

[jct842]

Get your self one of them magnets on a stick. They telescope like an antenna.

[jenningsjosh]

I don't think it will hurt anything being in there...

[jenningsjosh]

What size of rings should i order? here is what piston measures at... same on top...



almost 70 mm... so is it 70 mm rings or 69mm? thanks