"wash" means that they fuel is washing the carbon off of the top of the pistons. If the pistons are black, and dry all the way accross, you are actually getting lean. You should get a small area of wash by the intake ports, that will leave small "fangs" on the edges that are clean and wet.
If its a new MACH Z and hasn't been touched its
probably rich. All black and wet will be rich. Also
check your plugs along with the wash and usually
you can tell which way you are at. Black oily
plugs indicate rich. Brown and dry and you are heading
in the right direction.
Once you see the picture of the wash and you
get a bend-a-light and see it on the piston - you'll
get a better feeling.
This info on reading pistons is from a guy who has been building and racing 2-stroke outboards for over 30 years and winning.
Bright aluminium, wet or oily= very rich. fuel washing all the carbon off the piston top.
Hershey bar brown, semi dry and evenly coated with some wash at the tranfers is about right.
Light brown or tan , dry with small flake's of carbon standing up or missing is lean.
Doozer, I was having the same problem last year trying to read the wash on my 98 Mach Z. I don't know what's with these Zeds but I have yet to see any wash on mine either. I was running factory jetting and my piston tops were entirely black like yours. I installed a Tempa-flow last year and in the process of dialing it in tried to read the wash several times with no luck (the top of the pistons definately got browner the more I leaned it out but not once did I see any wash???). I had a few random looks down the cylinders of my dad's Indy 500 and a buds MXZ 700 and the wash was as plain as day (on my dad's sled even after putting around the yard slowly then having a peak, the wash was easy to see)??? I heard that flat top pistons show little or no wash but I'm not sure if thats what's in these things???
lets not forget one thing here guys. oil . the oil u run will play a big factor in reading wash. if u dont race and dont play with sleds that much dont pretend and dont bother trying to read your pistons. what colour are your plugs? black rich......... tan right..........light grey lean. keep it simple
machz69: Good point, If your not racing it,s best to be safe. Just look at the plug colouration for jetting information, to jet down looking for that last 2-3 hp most always has bad results spelled SEIZE. Dino
I find that the plugs are black even though my piston wash is spot on. The plugs are black but they don't foul anymore. I had to go to 45 pilots in a non-DPM sled. I would be VERY careful if you have DPM. I'm running 310 mains but they might be too rich, and with no snow, I can't ride it to find out. So, I would keep any eye on the wash and NOT the plugs, that will keep you from siezing. Good Luck!
Snow Tech had a really good article on plug reading and piston wash earlier this winter,Read it.
Oils play a very big roll as well as the type gasoline you use !
In the article it said to look at the bend of the electro as well as the positive ground and porcelain to read the plugs, If the plugs are white at the bend, positive ground and porcelain and white or gray on the piston top - YOUR TO LEAN.
look for brown, tan or a redish brown on your plugs and brown color on the piston tops, with only a few areas that have clear spots (transfer ports) Black piston tops could be either to rich (if wet) or to rich in some areas and to lean in another area and burning - or the oil just can't take the heat, period, or the oil is so tough it can't be burnt and should only be used on race engines.
I was running the regualr Doo oil when I was trying to read mine (and I usually buy my gas from Esso - 92 octane). I have since switched to the Shell Advance synthetic but haven't tried to read the wash again as I never realized that the type of oil you use had an effect on it (I ended up just going by the plug color to dial in my Tempa-flow). Has anyone had any luck reading the wash on the 809? I agree that one should not monkey around if they don't know what they're doing but there's nothing wrong with trying to learn if you have an interest in it. Everyone has to start somewhere!
yeah rockz your right .if it is to lern no rpob. i just dont want to see someone pop an engine trying to read the wash. if your running clotz its very very hard to read thats what i run. it does not leave a carbon . but if your trying to look at the wash it goes a little something like this. all wet and a clean looking piston (like brand new) well that would rich. but also will look like this way with some synthetics. lean would be all black even a little flaky. carbon.and dry looking. good will be black in the middle but the outer edge it will have a clean apperance at the point of the tranfer ports. again while your looking at the wash keep a close eye on your plugs. some synthetics u have to read the plug well good luck
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