Break-in with or w/o FPP?

[Larry B]

I am considering putting a FPP on my 675. I don't have an hour gage on my ski, but it is 6 years old and has been used every summer at least 3 or more weekends each year. It probably has in the area of 150 hrs + on the motor. It still runs good.

I had the head off at the start of this year and everything looked ok. Do I need to do a top-end rebuild before adding the new pipe? Also, if I rebuild, should I break-in with the FPP or the stocker?

[Bill O'Neal]

Larry,
Normally, I would never reccomend putting a FPP system on any motor that old without completely rebuilding the motor first, including the crankshaft and seals in the cases. You are asking for trouble.
Consider what you are trying to do. You are adding about 20-25% more power and a bunch of RPM to a very old motor, with very old seals and crankshaft bearings in it. Your motor does not have as powerful of an ignition as the 657x, so firing all that fuel after you rejet will present another set of problems. The crankshaft in the 93XP was completely inadquet(sp) for the XP, so what did SD do? They put it in the next years 94SPX and built a whole new crankshaft for the 94XP and all 657X motors. Your crank is not strong enough for any mods at all, in reality. No way would I modify a 93 or 94 657 motor, without replacing the crankshaft with a 657X crank.
Been there done that have the T shirt.....

[Larry B]

Bill,

Thanks for the advice. My ski does run great and I should probably stop trying to make this old boat go any faster before I get myself in trouble. Guess I am getting tired of going from one of the fastest skis on the lake (in 94) to one of the slowest. I should probably start looking for an 800 or something. Maybe a GSX or XP/SPX. There are a lot more parts available for those motors and they are getting a lot cheaper to obtain.

I have considered doing the 720 swap, but by the time I am done, it probably still wouldn't be what I really want or be as reliable at the 800, and I would have spent what it would have cost to sell mine and buy an 800. Guess I just needed to hear it from an expert who's been there.

[ December 12, 2001: Message edited by: Larry B ]</p>

[Bill O'Neal]

Larry,
Smart choice.