Apr 13, 2009 · Each on these piston types have their own place in the world of efficient engine combustion and from what I read, the forged pistons are best used in modified engines. But the cast pistons seem to have a better life because their ability to disapate their heat over the entire surface is a lot better than a forged.

May 11, 2012 · As far as pistons my opinion from best to good: 1. OEM (best). 2. Pro-X (very good) 3. Wiseco (good but..) The wiseco are forged and are a fine piston but you have to have a machine shop know what they are doing and experienced with wiseco because you can not set the clearances the same as OEM specs.

Sep 19, 2019 · Deegand22 pistons were cold seized, engine wasn't warmed up and heavy throttle and likely fairly cold water. When you see majority of damage/scuffing on sides of piston adjacent to wrist pin boss, there is more aluminum there and aluminum transfers heat faster than the cast iron sleeve can expand and the piston distorts.

Oct 6, 2012 · well i rebuilt my 787 with wsm pistons, i had 150psi before the rebuild but due to a large water leak at the bottom of the jugs i decided to replace the pistons while i had the jugs off. using the lowest crank gasket, 0.3mm i still get 2.1mm of squish when i should have at most 1.7mm my pistons are to short!

May 18, 2016 · My $0.02 is to stay away from forged pistons on watercraft. Not only is the setup very important but you have to make sure you warm them up very easy and good before getting on the gas. They expand at a much different rate than a cast piston and have gotten a bad reputation on watercraft because of this.

Jan 22, 2011 · hey guys, going to have a summer project going on, I'm going to big-bore me sled (iknow i know wrong forum) but i need 83.5 mm pistons wiseco says that the 718 and 787 both use 83.5mm pistons when Over-bored

Jun 13, 2017 · We just built a tool for that, and we are the only ones to do it to my knowledge.. www.seadoowarehouse.com choose a year then next to the model click the link that says "Listing" from there choose the assembly and then click the part number.. our database does a cross refrence, then displays all applicable models.

Dec 3, 2021 · WSM pistons need .0045" to .005" clearance so 3.270" is pretty much spot on. Of course, that is minimum sizes so you can get away with bigger. Be sure to chamfer the cylinder ports while you have them removed.

May 19, 2016 · My favorite tool is the phone. For $99 Group K out of Arizona will bore both cylinders final fit the pistons and chamfer all ports. They have been building endurance race skis since the 90's and know what they are doing with 2-strokes. Also seadoo cylinders are not Nikasil, just standard iron sleeves in aluminum so you don't have to worry about ...

Sep 15, 2013 · The leaner you go with a 2 stroke, it tends to make more power to a point, till it hits that magic 14:1 ratio and it's gonna be real close to detonation, which when it does, if detonation does happen, and it will if it's lean enough or the fuel is crappy enough (Can you say Seafoam, LOL!), then 2 strokes are known for quickly roasting pistons ...