1994 GTS motor apart, with pictures

[blacksc]

Hey Guys, i just bought a 1994 Seadoo GTS 5 days ago, seller said he had it for 2 months, started it and then it stopped. He had the heads off it and told me the bottom end bearings were gone. Anyway fast forward to now i finally got a chance to look it over and got the pistons off the rods and tried spinning the crank, it spins perfectly fine and smooth. Shake each rod and doesn't seem to have much play at all. NICE! sounds like the seller didn't know what he was talking about (i bought the ski in the dark so couldn't see much of anything) On a side note on piston is pitted up pretty bad, along with the head above that piston and the top ring is seized also. What would have caused that? Over heat in the motor or wrong octane fuel? Also BOTH the heads are cracked on the bottoms (see pics) What would cause that, and would it be ok to weld those up? or will i need new cylinder heads? Thank you. Marked on the pistons is 75.95 Austria, so i'm guessing thats still the stock top end? Probably time for new pistons anyway after 15 years. Any insight is greatly appreciated. On a side note i picture it up for $300.cdn. hull is in near mint shape as is the impeller and wear ring, just very slight grooves. I'm guessing thats not 15 years old.

Can these pits in the head be fixed or just leave it or get a new head?

 

[mudpie]

for the easy stuff first, the cracked jugs are from freezing!
prolly a glogged engine drain line , this kept water in the jugs and it froze and cracked the jugs, seen it many a times.
never tried to weld these, wouldnt hurt to try i guess
as for fuel, most older seadoos run fine off of 87, think it is recommened
the damage to the head could be milled out or ground out, but got to make sure there are no sharp edges or high spots that would lead to a hot spot!
this will also change your combustion chamber volume and squish area.
should be ok if not much material is removed
as for the marks on piston and head, some debris got into this engine
look for any missing parts, piston ring, piston pin clip, rod or crank bearing coming apart, broken spark plug , ect.
keep in mind that with a two stroke engine, anything that can get into the top end can get into the bottom end.
inspect that bottom end carefully before you reuse it
good luck
mud

 

[blacksc]

Ok both the spark plugs looked good in it. But previous owner might have change them out, who knows. As for cleaning the bottom end will i have to pull the block apart? i was hoping not to take all the timing stuff off etc. The pitted head does have some deep pits, i'll just buy a good condition used one. Thanks

 

[blacksc]

Ok i took the pieces into a motor cylce dealership adn talked to their tech who worked on seadoos for many years, he says the bottom end is toast and the piston picked up some of the pieces ( keep in mind crank spins freely and fine) He says the sleeves are good, but recomends a new top end kit and new crank. Now i have a question, can i not just buy new bearings and seals and press them onto the crank, instead of shelling out $400+ for a new crank? Also if i can't i'm leaning towards a SBT motor. Also he checked the head and says all the pitting is from awhile ago, but there were a few shiney new ones he said the head was good just wear marks and just need to sand a few of the spots down but its good useable.

 

[kustomkarl]

It's a 1994 seadoo...you can spend a little now and run it for a short while...till it goes again, or spend a bit more and have run for a longer time. If you can do the crank and a rebuild your self, it could be cheaper. If you pay someone it will be almost as much as replacing it with a sbt rebuilt.

Karl

 

[blacksc]

yea i want it to run for awhile, everything i have read says that these 94 GTS are a blast to ride so i want to keep it for sometime. Thing is a new crank is $295, top end kit is $195, plus gaskets and no warranty, i can pick up the SBT motor for $745 and have 1 year a warranty. Hmm what to do what to do.

 

[kustomkarl]

Like it said, if you do the work it is cheaper...but its still a 1994 engine other wise.

Karl

 

[blacksc]

did you have MSN Karl? if so add me at driving_ferrari@hotmail.com What other motors could i put into this ski without major modification.

 

[kustomkarl]

Your best to keep with what you got and just install a rebuilt. The module and all the electrical will be different if you upgrade. If you change to an updated it is all different, and will cost you lots of money. You could get it going and sell it and upgrade. It would be cheaper in the long run if you want to go to a newer seadoo, then trying to get a newer power plant to work in your old one.

I'm not on my puter...so I can't get on to msn...

Karl

 

[blacksc]

Ok thanks for your help Karl.

 

[blacksc]

Ok so i started pulling this motor apart to rebuild it. i saw alot of brown milk shake looking stuff and lots of water behind the oil pump and carb plate that bolts onto the block. Next thing, how do i get the flywheels off and the PTO???