Hi, I got the engine running yesterday! I wanted to bleed the coolant with the bleeding hole near the pto cylinder, but no coolant coming from here, even with the engine running. Why?
I ran the engine with the back of the snowmobile on a stand and I was looking at throttle response. Seemed good except at idle. When at idle, giving full throttle very fast and I was able to make it die, like if it was cold but it was running for more than 10 minutes. Jetting from pto; 146-146-148 and 42.5 for the pilots. Fuel screw were 1 1/8 turns out. So I took the carbs and losen the pilots to 2 turns out. Seemed way better, but still I think it can be more responsive. Should I go with 3 turns? Idle is at 1800. Plus the temps are warm outside, so it should be running rich now, not lean.
Well then happened something scary...I was riding it around the house a little and it started to loss power and...backfiring. Go in the garage again. PTO cylinder not working. Removed the spark plug and there were unidentified chunks on it.

Pulled the powervalve to check the piston, looked good. Back to the spark plug, removed the little chunks...right stuff chunks, like silicone. Oufff...I really hope it's that, coming from the crankase, it should makes sense.
I'll put a new spark plug and see how it goes...stay tuned.