robert0762 Posted May 14, 2010 Report Share Posted May 14, 2010 Can piston wash be used as a good indicator of needle jetting? I have read thet a lot of snomo guys practically live buy it. Just wondering how reliable it is for a banshee Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 14, 2010 Report Share Posted May 14, 2010 It is ultimately the best jetting tool there is. However, not many feel like taking a head off to check for jetting, it can be time consuming. You can use it to check for the needle...if you never really get past 3/4 throttle and ride it for a while like that. It takes a little time for piston wash to occur... Spark Plug heat/color is much easier to read, and if done right is just as effective. Piston wash can tell you more than just jetting... It can tell you burn pattern, for example as well... Quote Link to comment Share on other sites More sharing options...
robert0762 Posted May 14, 2010 Author Report Share Posted May 14, 2010 (edited) Good to hear. so by looking at these pistons i would say that I am safe to lean out one notch. I ride trails and dont hold it wide open for long if I ever get a chance to Edited May 14, 2010 by robert0762 Quote Link to comment Share on other sites More sharing options...
robert0762 Posted May 14, 2010 Author Report Share Posted May 14, 2010 Also it looks like the piston is hottest rite at the intake side . From most of the info I have found this is backwards correct??? Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 14, 2010 Report Share Posted May 14, 2010 You've got that backwards... It's burning off on the exhaust side...that's why you don't see a buildup. I'd say you're safely rich. That's some pretty even burning, as well... Quote Link to comment Share on other sites More sharing options...
robert0762 Posted May 14, 2010 Author Report Share Posted May 14, 2010 (edited) You've got that backwards... It's burning off on the exhaust side...that's why you don't see a buildup. I'd say you're safely rich. That's some pretty even burning, as well... Heat of the piston chars the oil as it comes into contact. Areas where piston is cooler i.e. intake areas the oil does not char. Thats what I thought happened. But you are telling me that the exhaust side will burn it off? Do you think i can lean out a little. I think I can but just want a second opinion. It feels good when i ride but I think it can go just a tad leaner to be perfect . Also plugs are black Edited May 14, 2010 by robert0762 Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 14, 2010 Report Share Posted May 14, 2010 Depends... If you spend most of your time wide open, lean out the main one to two sizes. If you don't, it could be fine on the main and rich/lean on the needle. The top of the piston is hot. It's hotter towards the exhaust side. The first air/fuel out of the cylinder is on the exhaust side...then the piston goes down further and gets a clean, cool/fresh charge of fuel. If there is a lot of left over fuel/oil that doesn't get burned it'll stick on the intake side since that's where the cooling is happening...the exhaust side is all business. Fresh fuel/oil charge is what cools the top of the piston...but it only needs so much to do so. Too much (rich) causes build up, too little...well, we know what happens to a lean motor. Quote Link to comment Share on other sites More sharing options...
Profilact Posted May 17, 2010 Report Share Posted May 17, 2010 How much runtime is on that motor? Reason I ask: Bigger Pics here: left right Quote Link to comment Share on other sites More sharing options...
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