shaggyzr2
Active member
How long should you have to run the sled to get a good reading for piston wash?
YAMMIEGOD3:16
Active member
if jetted correctly, i believe afew good weeks of hard running. 3:16 (yammie tony)
shaggyzr2
Active member
Yeah...I was out riding it tonight for a while, checked the wash and didn't have a whole lot of carbon build up on it yet so I rode it some more and it was darker the second time I checked it. Plugs were a caramel color. I think I'm finally getting this thing figured out, looking like jetting was my problem. Rode it saturday in about 20 degees and seemed decent but would only get up to 8000 rpm, tonight it's in the single digits, got her up to about 8400 rpm and feels much quicker.
Missing a chunk out of the mag piston. Any opinions on the wash much appreciated. This cracked after running hard all day in powder at about 10 degrees. Cylinder might be salvageable. I suppose the crank has to come out and cleaned??
The reason the piston is missing the bottom skirt is because the piston is worn and the skirt to wall clearance is too big. Nobody put rings in the sled and the pistons wear the skirts, so it will eventually break them off from rocking back and forth in the bore. The other 2 will do the same thing also.
Theres no wash to read due to the detonation on the piston, take a picture of the other 2 that have not blown up (yet)
buy 3 new pistons and rings for that engine. wristpin bearing and circlips. you might be able to retrive the chunks if you shut if off right away, but the safest way would be to split the case and clean it out, throw in a set of crank seals while your there and it will run for a long time agin.
Devilin AblueDress!
New member
100% agree!
Thanks for the input - I've got a long history with this motor. Bought it blown up 2500 miles ago when it had just about 1,000 miles on it. That time, the center piston was shattered. Skirts on both sides cracked. Then rebuilt it with a new crankcase and crankshaft. Then goofed putting that back together and wrecked that mag piston and cylinder. Bought a used cylinder and matching piston set. So my hunch is that used set had more miles on it than advertised and I didn't know better. I'll take a picture of the other two. They are original with the motor. By my novice eye, those pistons look good.
The skirt got mashed. The right thing to do is to split the halves and clean it out.
Is the cylinder salvageable if it's not scored?
The skirt got mashed. The right thing to do is to split the halves and clean it out.
Is the cylinder salvageable if it's not scored?
Last edited: