engine rebuild T350

[woertske]

I have bought a set of pistons and piston-rings(first oversized)
There is a L-ring and a normal piston-ring.



Can somebody tell me what the gap has to be when I put a ring in the cylinder.
On the wiseco paper they say that the L ring = 0.08".



What is this in millimeters?
And can someone tell me what the gap has to be from the normal ring??

Please help me out

[Alan H]

Read it again.
It is .008 inches, (not .08 - big difference), that is 8 thousandths of an inch.
There are just under 39 thousandths (thou) in a millimetre, so 8 thou is 0.2mm.
.08 inches is 2mm, far too large a gap.

You can use this to check if you wish http://www.convertunits.com/from/inches/to/mm" onclick="window.open(this.href);return false;

[woertske]

Alan H Thanks..
Good that you mentioned it(0.008")
So for the L it is 0.2mm.
For the good order: Also for the other ring?

[Alan H]

Both rings same.
Just remember that on a two stroke the piston ring grooves are 'pegged' so that the rings can't turn and the ends get trapped in a port. If you look at the position of the pegs when the pistons are fitted to the conrods, you'll notice that the pegs run a line between ports.
I've had different types of ring end on different bikes, so look at the shape of the ends before you try to alter the rings - they should fit the pegs and may be rounded or flat depending on type, manufacturer and use. Four stroke rings are usually flat end and can rotate in use (no cylinder ports).
So if you can't get the piston to enter the bore when the rings are on the piston, it may be that the gap is too small and the ring ends are butting up to the peg so the ring can't 'bottom' properly in the groove and that the rings appear too large to run in the bore.
Like the blurb says, a slightly bigger ring gap is less problem that a tight one.

[woertske]

Thanks Alan for your answer!!

Super