Do I need new piston and rings?

[Marylandrider15]

Last weekend after a few minutes of riding I came to a stop and at idling my engine rpm went sky high. I cut it off let it cool offfor a while. I kicked it over and it backfired one time! Kicked it again and it started fine and did the same thing with the idle so I took it home.

Checked reeds
Checked spark plug
Fuel is clean and mixed correctly

Did a leak down test and found I was loosing way to much pressure way too fast.
Sprayed the engine down and couldn't find a leak. Took the stator off and checked that seal no leaks.
Listened to the crank vent tube and didn't hear no air coming from there.
So I figured I'll take the jug off and inspect the piston and things and to see if I had oil setting in the bottom off it. This is what I saw

Should I be looking for a new piston and ring set?

 

[Awk08]

I see no scuffing on the piston
ring ends on the location pins ?
what is/was the compression ?

since you have it apart, measure piston to cylinder clearence like this with feeler gauges
http://www.blasterforum.com/threads/how-to-measure-your-cylinder-diy.25767/

compression and piston clearence will tell you if you need a new piston/bore.

you'll need at least a new base gasket now and clean off all of that old one from the cases/cylinder bottom
a new head gasket or anneal the one you have
new rings and a quick hone wouldn't hurt if all else checks out
upon reassembly, leakdown test again and find the leak if there is one.

 

[Marylandrider15]

I see no scuffing on the piston
ring ends on the location pins ?
what is/was the compression ?

since you have it apart, measure piston to cylinder clearence like this with feeler gauges
http://www.blasterforum.com/threads/how-to-measure-your-cylinder-diy.25767/

compression and piston clearence will tell you if you need a new piston/bore.

you'll need at least a new base gasket now and clean off all of that old one from the cases/cylinder bottom
a new head gasket or anneal the one you have
new rings and a quick hone wouldn't hurt if all else checks out
upon reassembly, leakdown test again and find the leak if there is one.

I already had a base gasket on hand. Didn't get a chance to use a feeler gauge but I got everything bolted up and I'm still having a air leak. So I'm going to take the clutch cover off and look for a leak on that side.

 

[bummer981]

Use soapy water in a spray bottle while you have the engine pressurized to find your leak.

 

[Marylandrider15]

Use soapy water in a spray bottle while you have the engine pressurized to find your leak.

Yea I did that before and couldn't find it so I'm guessing it's on the clutch side.

 

[Marylandrider15]

Well I got the clutch side off and was able to spray it down. I've done replaced all seals and that collar behind the gear last year for the same leak. sh*t sucks,

But I also have air coming from the trans side thru the oil holes. Thinking it's time for a rebuild and a big bore

 

[Awk08]

This should fix the crank collar leak.....

http://www.blasterforum.com/threads/crank-collar-seal-vid.50433/

 

[Marylandrider15]

This should fix the crank collar leak.....

http://www.blasterforum.com/threads/crank-collar-seal-vid.50433/

Did that on the last collar but it was still leaking. Had to get a new one.

 

[Awk08]

Did that on the last collar but it was still leaking. Had to get a new one.

Hmmmm, possibly wear on that crank then ?

 

[DUALSTROKE]

If you have leaks coming from the trans side oiling holes then your cases are not sealing correctly.

 

[Marylandrider15]

Hmmmm, possibly wear on that crank then ?

Yea probably so… that's why I want to go ahead and get a rebuild going