Hole in piston

thanks for the info, i guess thats one more thing I will be tearing into, the only reason I suspected the gas thing is because I smell the gas when I drained the oil.

So I checked the jets real quick today, main: 110, pilot jet 1: 20, pilot jet 2: 50. Does that sound right for the bike with a 4-1 baffled exhaust and pods?

anyone?

A 78 650 SR with carbs that has the additional 50 jet over the pilot jet. Sounds like a D1A that came with vm22ss carbs. Stock the vm22ss came with a 90 main, and a 15 pilot. I would think a 110 main and 20 pilot may be a little too large for the 22s.

On the other hand if the carbs are the vm24ss that came on the D1, but it is my understanding did not have the additional 50 jet over the pilot, came with 102.5 main and a 15 pilot and a 110 main would be a good starting point for pods and exhaust changes. Most of the time a 17.5 pilot is also required with pods and pipes. But a 20 may be too big.

A couple of ways to tell just which carbs you have are as follows:

There is an ID stamped on the flange just below the choke handle that will ID the carbs. If you post what is there I should be able to tell you what you have.

You can also look into the intake bell (pull a pod and look) and the 22s have an additional port at about 10 o'clock that the 24s do not have. See pics below - first shows where to look for carb ID stamp. The second is of a set of 24s on top and 22s on bottom - note the additional port on the 22s.

I looked and it has the extra port and the side it has "n8" and what looks to be "11".

Update, so I got the engine out and took off the oil sump and there is metal and what looks to be silicone everywhere. Doesnt look like I can just flush out the engine.