Tore apart my first 550 what can I do to make it faster?

[Sailin817]

:bigeyes: Hey all,
I have a 1987 550 that had a scored cylinder wall.
I plan on taking this to get honed (or bored over)
what options are there to get more power out of her?

My Uncle has an old 550 we are racing to see who gets theirs together first.
And of course, I would like mine to be faster than his.:sneaky:

I was thinking to get the head shaved down a bit to get higher compression?
(How much should I shave?)

Also since this is a first for me, anything I should look out for while rebuilding?

Thank you all,
Andre

 

[RiverRat]

Don't put any $$ in it, buy a SJ..............there I said it first :arms:

 

[LBE]

Well as a newbie you are going to hear a lot of comments like River Rat's. The reason is: Its true. Rebuild thet 550 as cheap as possible. Ride it, learn to ride and save your $$ for a Yamaha. Even a square nose Super will have more possibilities for modification and will be more reliable.

I'm not knocking your 550, I have had several. You just seem to have more optins and potential with a Yami. I was a die hard Kawi ridder for a long time, then I got a Yamaha, all down hill from there. No sence in putting $1000 in mods into a ski thats only worth $800.

 

[GDFL]

Just be mindful that a running 87 550 isn't going to be worth more than $600 in most markets. Before you pour much money into it, weigh your options and then realize that you need to buy a superjet. Just kidding about the superjet part, but don't dump too much money into an old 550.

 

[DBLOCK]

I have a 650 SJ and a JS550. I'm happy with both for playing around on. I think you can do lots to your ski without shelling out lots of $ and make it a better version of what it is - a lightweight relatively underpowered ski (based on everything else available now days).

Free mods assuming you have some basic shop equipment:
Pump blueprinting - remove the casting mismatches using a dremmel tool
Cylinder port clean up or mild port job.
Cylinder hone - if the walls aren't scorred too bad
Disable the rev limiter
Port the case for better air flow (basically, knock down all the sharp corners as the air flows between the case and transfer ports)
Clean or rebuild your carb.

Reasonable mods - relatively low cost:
Replace the oil seals. I'm sure it hasn't been done since new.
Check your crank bearings while you have everything apart.
Aftermarket head or shave some off yours. Another trick is to use copper base and head gaskets to increase compression. Thickness of the gasket will depend on compression desired. Beware of going too high of compression - this will result in detonation (if it affects your squish area).
Lower pitched SS impeller.
Bore the pump nozzle out to 68mm. (this will result in faster off the line acceleration).
Newer style exhaust (and/or 1/2 pipe).
Upgrade pistons to SX style - longevity and cooling reasons.
Mod the waterbox.
Lighten the flywheel.

Read the 440/550 Bible thread over on PWCToday.com for most of these mods... Also read GroupK.com writeups on the 550's.

I'd say this would get you close in performance to my stock 650 SJ... there are handling issues that make the SJ a much better ski though.

Good luck!

 

[kawirider00]

put a 650 in it

 

[jeepmark4x4]

dude he's not kidding..I'm having a hard time selling an old 550 for 150 bucks that even runs! As I said before. I would rather not ride than ride a 550

 

[LBE]

I would rather not ride than ride a 550

Thats harsh. I'd rater ride a js300 than nothing. If I'm on the water, thats a good day.

 

[djyox]

I rode my 550 for a long while, and still will ride it. I ended up dumping loads of cash into it for little gains. I just wanted to keep up with the rest of the group that was newer SJ and SXRs....

I also didn't jump on the SJ bandwagon for ever because they are hard to find in my area. But I have a basket case now, and I am going to do my best to never look back at the old 550s... They are great fun but just watch out, they are money pits...


Shave the head at a shop ($25) find a pipe off of ebay ($100) get a 15.5 prop ($75) call it good there, or get quick steer too.. I really like that, oh and new bars.. but bars and quick steer are just like another $20... AND keep your stock parts because selling a stock ski vs a built one doesn't seem to bring in much more cash, much better to part out the aftermarket stuff, and sell the ski stock for a little less...

IMO.. But others have been down the road too and can tell you too..