Super Jet first superjet build help?

[cbail]

hi im cody, 16 years old and im a diesel fitter apprentice this is my second ski,( first one that needs work) well i got this jetski for a carton of beer, pulled apart as the guy was going to put in a boat, i put the jetski together rode it a few times, it seemed to be low on power so i pulled it apart to find that the back cylinder and piston had heavy scoring, which i believe is to be caused from a leaking crank seal, because when i removed the inspection cover of the fly wheel fuel poured out. it has a 6m6 crank, 6m6 bottom half case, 62t top of case, hot rods conrods, 61x cylinders and a riva high compression head, also can anyone tell me if these are wiesco pistons, also front piston/ bore is almost perfect, also my impeller was grinding on some high spots in the jet unit, and the impeller has no identification letters/numbers, also can anyone tell me if it is possible i could have a 701 cdi with the 650 strator

 

[cbail]

more photos to come

 

[cbail]

more photos

 

[Buckwild12]

I'm not the best guy when it comes to fixing broken engines, but I'm sure some of the other members much more qualified than me will help you out.

 

[Sospikey]

That piston sure is toast! I'd check the crank for damage from the debris of that piston. What's with miscoloration of the cylinder on the outside? Been running hot? Dual or single carb? Is the carb/-s jetted for the b-pipe?

 

[surfjunkie]

you got a complete superjet with a b pipe for a carton of beer??

nice. beer sucks anyway

and you already know way more about engines at 16 than i do at 45.

 

[cbail]

there is light pitting on the crank weights, im going to soak it in petrol and see how smooth the bearings are, also its running a single mikuni 44 , and i believe with all the porting and stuff i would assume the guy that owned it before me new what he was doing, does anyone have the base jetting for a superjet so i can check

 

[cbail]

more pictures

 

[cbail]

Bump,help please, the cases are trenched is it worth stroking?

 

[cbail]

Bump,help please, the cases are trenched is it worth stroking?

 

[Schmidty721]

hi im cody, 16 years old and im a diesel fitter apprentice this is my second ski,( first one that needs work) well i got this jetski for a carton of beer, pulled apart as the guy was going to put in a boat, i put the jetski together rode it a few times, it seemed to be low on power so i pulled it apart to find that the back cylinder and piston had heavy scoring, which i believe is to be caused from a leaking crank seal, because when i removed the inspection cover of the fly wheel fuel poured out. it has a 6m6 crank, 6m6 bottom half case, 62t top of case, hot rods conrods, 61x cylinders and a riva high compression head, also can anyone tell me if these are wiesco pistons, also front piston/ bore is almost perfect, also my impeller was grinding on some high spots in the jet unit, and the impeller has no identification letters/numbers, also can anyone tell me if it is possible i could have a 701 cdi with the 650 strator

Per the part number on the piston, they are not Wiseco's. Either way, that cylinder will need an overbore and two new pistons will need to be purchased. Right now. your at .5mm over stock bore.

I would ditch that wear ring that has the high spots and either purchase a good use OEM piece or a new aftermarket. Can't help you with the impellor indentification.

650cc, 701 61x use the same flywheel stator combination. Everything in the electronics is the same between 650 & 701 61x with the exception of the CDI. 701 61x CDI has a higher rev limit than the 650. 701 62t CDI has a little different wiring and a different stator/flywheel combination.

I woudn't even consider stroking it. Trenching the cases is the cheapest component when it comes to building a stroker engine. Your talking minimum of a couple K to build a decent stroker engine... and thats doing everything on the cheap side. Your engine appears to have decent port work done, take it to an engine builder, have them look at your cylinders and get it bored and order the correct size piston. Rebuild it with new OEM crank seals, check your squish & cranking compression, do a leak down test and run it!

 

[cbail]

ok thanks, i took it too the shop and ill be running 82mm forge pistons