piston wash?

[simofx-1]

i had my 701 rebuilt about 30hrs ago, and was wondering how long it should take to show a good collar on top of the piston? at the moment its not that dark at all

 

[wanderer1]

You have a pic, 30 hours should show piston wash unless you have water ingestion that would "steam" it off.

 

[simofx-1]

i have no pic, because im looking througth plug holes, the ski runs mint but i was wondering if im running a tad rich? as the piston is light brown .

the pistons ive seen are from 10 plus years use and they are black all over

 

[wanderer1]

Or overly rich, I forgot to mention that. Wow 10 year old 2 stroke pistons? That's luck lol. If its running great should be GTG, a little rich don't hurt.

 

[Quinc]

Or overly rich, I forgot to mention that. Wow 10 year old 2 stroke pistons? That's luck lol. If its running great should be GTG, a little rich don't hurt.

^This, the extra fuel could be keeping it clean.

 

[wanderer1]

Better than lean

 

[Harbor]

Reading piston wash thru the spark plug hole ?....

I have looked thru the plug hole while my plugs are out, for GP, see different things, sometimes it looks black and oily other times it's more dry and clean. When I remove the head though it can be clearly seen, neither was correct. It was a combination of both spread across the piston a distinctive pattern.

These pics are after 30 to 40 hours, race gas, .018 squish, lots of timing early. It looked real oily thru the spark plug hole, I was suprised when I got the head off, I wiped the loose oil off and this stained remained. Unfortunately I didnt take the pics before hand