Banshee full rebuild

[James-26]

So I was fixing a blown head gasket on my shee and dictated to also replace the base gasket while I was in the engine. Good thing I did I found that the left side crank has pulled apart where the Big end of the rod meets the crank. It has pulled out an amazing .030 WTF.

 

So I have bought a new crank that has been welded and trued, I bought new OEM outside crank bearings and seals, Wiseco Pro Lite pistons to replace my Cast WSM pistons, All new gaskets, and I'll prob also have my head shaved .025. I was going to send my cylinders off to RB Racing to have the trail port done but I'm running low on cash now. Guess I'll do that later.

 

This will be my first time inside a banshee engine is there anything I need to watch for or do? Is there any other parts I should add, mod or replace while I'm inside the case? Will I need to rejet the carbs for the wiseco pistons?

 

Oh I have not bought wrist pin bearings for the wiseco pistons yet. Should I replace them or can I reuse the bearings from my WSM pistons? Or is there a certain wrist pin bearing wiseco has to use?

 

[TwistedSheeRida]

Good thing you caught that early or you'd be putting a little more dough in the build. Wrist pin bearings are about 10 bucks for the 2 of them so i would just replace them even if the other ones fit, which they should. While your in there i would go ahead and replace the tranny bearings, make sure your shift forks are still in good shape, might as well do the shift shaft and shift star mod also definitely a big difference in shifting. Measure your clutch springs if the clutch wasn't slipping before chances are your all set for now but doesn't hurt to check it out while your in there. And you shouldn't have to re-jet the bike since your not messing with any difference in air/fuel mixture. Hope this helps and have fun with it.

Tony

[James-26]

Alrite I'll go ahead and get the wrist pin bearings ordered. My banshee we rebuilt back in Feb of this year (i was told) and I can still see the bore/hone marks in the cylinder walls, will I need to hone before installing the new pistons? The guy at F.A.S.T. told me to just check clearance and install the pistons.

 

On one of the Cast WSM pistons the pin that holds the rings from moving around started to come out and put a minor mark maybe .003 deep in the cylinder wall. Is this going to hurt anything when I install the new Wiseco pistons?

[bansheesandrider]

Alrite I'll go ahead and get the wrist pin bearings ordered. My banshee we rebuilt back in Feb of this year (i was told) and I can still see the bore/hone marks in the cylinder walls, will I need to hone before installing the new pistons? The guy at F.A.S.T. told me to just check clearance and install the pistons.

 

On one of the Cast WSM pistons the pin that holds the rings from moving around started to come out and put a minor mark maybe .003 deep in the cylinder wall. Is this going to hurt anything when I install the new Wiseco pistons?

The mark is going to cause your rings to leak. The other problem I see here if you are not boring it to the new pistons is that cast pistons require more piston to cylinder clearance than a forged piston does. This means that the Wisecos will have too much clearance when you put it together and you will have piston slap. Anytime you replace cast pistons with forged pistons in a Banshee, you need to bore the cylinders to have proper clearance to the forged pistons.

[James-26]

Interesting I wonder why the guy at F.A.S.T didnt tell me this? He told me that there would be no reason to bore and to just drop the new pistons in a I'll be good. Guess he was more worried about getting a sale in. What should my piston to wall clearance be with the wiseco pistons?

[James-26]

okay so I got my wiseco pistons today. I checked my Piston To Wall Clearance and I'm around .001 to .002 P.T.W.C I think I'm good to go. The wiseco pistons feel tighter inside the cylinder then the Cast pistons do.

When I check my piston to wall clearance I flip the cylinder up-side-down and install the piston as it normally would be. I then force the piston all the way to one side of the cylinder and insert a feeler gauge between the cylinder wall and piston skirt. I know this is how to check 4 stroke P.T.W.C but not 100% 2 stroke is the same. Some one correct me if my method is wrong.

[James-26]

okay so I got my wiseco pistons today. I checked my Piston To Wall Clearance and I'm around .001 to .002 P.T.W.C I think I'm good to go. The wiseco pistons feel tighter inside the cylinder then the Cast pistons do.

When I check my piston to wall clearance I flip the cylinder up-side-down and install the piston as it normally would be. I then force the piston all the way to one side of the cylinder and insert a feeler gauge between the cylinder wall and piston skirt. I know this is how to check 4 stroke P.T.W.C but not 100% 2 stroke is the same. Some one correct me if my method is wrong.

 

Bump

[dirtydownunder]

yeh man, piston clearance is piston clearance, tho check it in two places, one inline with the wrist pin and 90 degrees to it.

 

.002 is a tad to tight for a forged piston, im not shaw what wiseco recommend. but forged pistons grow quite a bit when warm.

 

i ran a lil search and people are saying .002 is fine, but id double check that with wiseco...

 

wiseco reckon this...

 

03. What kind of piston-to-wall clearance can I run?

A.

The factors that affect this are cylinder wall thickness, whether the block is filled, the overall compression height of the piston, piston material and thickness, and whether a marine engine is to see fresh-water cooling. Most small blocks get .004 piston to wall clearance and most big blocks get .005 due to the use of our 2618 high-strength alloy. For heavy blower and nitrous applications, Wiseco recommends adding .001 to the standard clearance. Special note: Clearance numbers are obtained from measuring the largest diameter of the piston, typically at the bottom of the skirt. All measurements should be taken 90 degrees from the pin centerline.

[Larry's Shee]

Only accurate way to check clearance is with a micrometer.

[James-26]

Only accurate way to check clearance is with a micrometer.

 

How do I go about doing this.