Top End Rebuild, Bottom End Also?

[Kovechkin450]

My 1997 Seadoo GS has recently started acting up and losing power so I did a compression test and the readings were 85 and 95 psi, put a little oil in the cylinders and both jumped to around 120 psi. This leads me to believe that the piston rings are in need of replacing. I took the head off and the pistons and cylinders look in great shape so I was thinking I could get away with just doing the piston rings, or at the very least rings and pistons. However, I'm not the original owner and I'm not sure if the bottom end has ever been rebuilt and my concern is that by greatly increasing the compression that the bottom end will fail soon after.

Any thoughts on what I should do? I'm mechanically inclined enough that i could rebuild the top end on my own but I don't feel confident enough to do the bottom end even with a shop manual at my side. Any idea on what it would cost to have a shop rebuild the bottom end? parts and labour? Also what is worst case scenario if I just to the top end?

Any help and/or advice would be greatly appreciated, thanks!

 

[LouDoo]

New rings will be a temporary fix at best, if this is the original engine to the ski I would buy a rebuilt engine as the crank is 15 years old. Or if the hours are low and you already have a replacement engine do at least a top end.

Lou

 

[Kovechkin450]

New rings will be a temporary fix at best, if this is the original engine to the ski I would buy a rebuilt engine as the crank is 15 years old. Or if the hours are low and you already have a replacement engine do at least a top end.

As far as I know it's the original engine, I have had owned it for 5 years so can't say for sure. How much does a rebuilt engine go for?

 

[LouDoo]

Looks like about $ 750.00.

http://www.shopsbt.com/jet-skis/seadoo-jet-ski-engine-standard.html

Lou

 

[Dr Honda]

The new found power from a set of rings could be the nail in the coffin for the lower-end. But... then, again... rings, base gasket, and exhaust gasket are only about $50, and an afternoon to install. Since you didn't have a melt-down... I'd chance it.

 

[Kovechkin450]

Ya that's what i was thinking. Then hopefully I can finish out the season and then sell it this fall or next spring and get myself onto a newer faster machine.

 

[Spimothy Leary]

Looks like about $ 750.00.

http://www.shopsbt.com/jet-skis/seadoo-jet-ski-engine-standard.html

Lou

plus shipping both ways...! your much closer to $1,000 with that, they don't give away their shipping at sbt.

i'd chance it if I were you, but i'm a little nuts. a 717 crank really isn't that expensive,
i'd personally gamble with your sub $100 fix first, see what happens, if you get lucky you get more time before the eventual rebuild, i certainly wouldn't spend $950 on an engine replacement, the worst that happens is that you spend less then $100 it blows, then you spend $950 on an engine, or do a complete rebuild.

edit.. just saw honda's response,,, i agree.

 

[Kovechkin450]

plus shipping both ways...! your much closer to $1,000 with that, they don't give away their shipping at sbt.

i'd chance it if I were you, but i'm a little nuts. a 717 crank really isn't that expensive,
i'd personally gamble with your sub $100 fix first, see what happens, if you get lucky you get more time before the eventual rebuild, i certainly wouldn't spend $950 on an engine replacement, the worst that happens is that you spend less then $100 it blows, then you spend $950 on an engine, or do a complete rebuild.

edit.. just saw honda's response,,, i agree.

Ya i'm in canada so i would have to pay the shipping and brokerage and duties and all that lame stuff so ya i could easily be at $1000 for a new motor. I'm gonna go with the cheap easy way first and see where that gets me. Thanks for the input guys, i won;t get around to doing it for a couple weeks but ill let ya's know how it is goes and if it;s working good after the break in period or if i ended up swimming back to shore :willy_nilly:

 

[Spimothy Leary]

lol, always remember never ride alone, ESPECIALLY on a test run.
i have a good friend thats a mechanic i go on test runs with him all the time,

 

[Kovechkin450]

haha ya no worries i have a few seadoo buddies at my trailer park plus there are lots of people in the park with boats and i wont venture to far from shore so people would see if i broke down and drive out to me.

 

[Kovechkin450]

hey guys i had another question, anyone know how much CC's are gained by boring the cylinders to the next size?

 

[Spimothy Leary]

hey guys i had another question, anyone know how much CC's are gained by boring the cylinders to the next size?

negligible, you're not going to notice anything IMO

 

[Kovechkin450]

ok thanks, another question, i see in the shop manual you need to apply Bombardier Lube to some things, is there another kind of grease/lube that you can buy rather then using the "seadoo stuff"? I have a feeling my local dealer will want me to give them my house for it like they do everything else.