Engine problems

[j440]

So i bought an 02 banshee, rode it 2 weeks no problems. Let a friend ride it and he held it WFO way to long and it locked up. Big deal shit happens. Well I pull this thing apart.. suprise fully built banshee. Chichis in miami apparently built it (engaved on the cylinders) It has porting, blaster pistons, a twister crankshaft, carbs, adjustable timing plate, jp clutch etc... Guy I bought it from had no idea lol.

 

Mind you I have done topends on 2 strokes but never really mess with them all that much.. So bear with my questions lol.

 

Anyways, the right cylinder is done.. The skirt broke off the piston and broke the sleeve. cylinder is cracked in the exhaust port. You can tell they were epoxied so im assuming the porting was pretty in depth.. Thinking buy used stock cylinder and have it matched? Peices everywhere on that side. Left side untouched. My question is, the bottom engine case is marked up from spinning with chunks of metal down there, how does this affect things? No cracks just scratched up in the center. The top is also marked up alittle worse, Sure I can have someone fix the porting but the rest of it Im not to sure... The crank seems fine, i cleaned it all up, bearings feel normal, no up and down play on the rod, nothing jammed in anywhere or marks. Its billet so im assuming it should be fine...

 

So my main question is, how critical is the engine cases being alittle torn up? I know the top is ported (or was). Ill have to have someone match the porting and clean it up.. or get new cases and have someone port it again correct?

 

What about twister cranks? Never heard of them untill today. If it does need a rebuild is it possible to get that done? And how do I identify if its a stroker crank or not? The number on it does not match up to the part numbers on the website..

 

Thanks. Heres some photos of the cases.

[j440]

 

 

 

 

[trickedcarbine]

You're not in to bad a shape. You have a lot of options.

 

To measure the stroke. You probably will have to mock the motor up real quick. Just toss the crank in the cases. Put a piston on with out clips and put a straight edge in the bore. Roll the crank over and mark on the straight edge at the highest point of the stroke and lowest. Measure it in millimeters. 54mm is stock stroke, 58mm is +4mm, and so on. Twister has some of the baddest cranks on the market! If it's in good shape hang on to it. Maybe change the bearings. If it needs a rebuild send it to Lew at twister.

 

Cases are fine. Clean them up nice and check the surfaces and threaded holes. From the pics they look ok. Nothing wrong with a little road rash in side. Clean any burrs up though.

 

Those cylinders are junk! Not much special work done in them at all. The transfers just barely got touched. No point in saving them and re sleeving them. The porting just isn't anything special enough to salvage. Figure out what stroke crank you have and maybe get lucky and buy something used here. If that crank is 58mm there is a nice brand new redline top end ready to go in the forsake section. Either way. Figure out that crank's stroke and go from there.