300/440/550 newby 87 JS-550 owner

[skigolfnut]

I just bought a vintage 550 for my 11 year old son to ride here in region 5 in Texas,
what is the air intake set up? someone put an extra air intake up front, and the previous owner plugged it up,
The ski came with a few mods-1987 kawasaki js550 bored .30 over, wiseco pistons, high compression head, 44 mil mikuni carb, all new red silicoln water and fuel lines, west coast alluminum water box, muffler removed, primer kit, alluminum nose hull rienforcment, quik steer, aftermarket handle bars, jetsport ride plate with r&d 17 degree stainless solas impeller.

Sould I convert the thumb throttle to a finger pull type?

any other pointers?
thanks,

 

[skigolfnut]

here are some pics of the engine, it came with another exhaust manifold and another pipe,

 

[Elevation]

Nice deal. A set of straight bars, and a finger throttle insted of the thumb one would make a huge difference.
And maybee even a spring for the pole.

 

[special fx]

Couple things to take care of promptly.......

- get a coupler cover
- get rid of the pre-'86 exhaust that someone put on there and replace with a '86 or newer.
- get a flame arrester of some sort

 

[skigolfnut]

See attaced picture of the new exhaust that came with it, it has a K&N flame arrestor, it is just taken off for the picture,
Someone had put an extra vent hole in the cover but the last owner blocked it off, he said that water poured in, see picture,
Here is a better picture of the exhaust that is installed,
Should I put the Exhaust on that came with it, or upgrade all together?
thanks,

 

[Polish jet pilot]

I'd put everything as it was - in this case you get some possibility that it was a full tuned package. KN cotton filters are not good as they soak water in and restric airflow (when wet).

 

[skigolfnut]

The picture of the Exhaust was made by Orange County Jet Ski, is it worth putting on??
My funds are kinda strapped having children 16-11 and 8 and being Christmas time, if you know what I mean,
I fired it up on the hose the other day and it seemed OK, it just had a hard time running at idle speed,
It seemed to be a fuel issue, when it would start to die, I would prime it with a little more fuel in it and it would stay running, runs fine at 1200 prms and up, but just wont idle??
any ideas?
thanks,

 

[skigolfnut]

Thanks for everyone help, the Low and High carb adjustment screw were way out of wack,
I adjusted them accordingly and it purrs like a kitten now,

 

[restosud]

if the pipe is the short version don't install it.the long pipes are more desirable especially on a 550.
you could try to bring the air pipe up into the hood to limit the water intake but still not ideal.it's true that the oem hoods are restrictive if boat is modified though.

 

[skigolfnut]

Yes it is the short version, I have to have a stock exhaust for my son to ride in the Jr. division, so I am going back with a 97 stock bread box exhaust, John Zig said it will be a lot better than that 94 exhaust that is on there now,

 

[hillbilly550]

if you still need it, i probably have a post 87 exhaust you can have if you want to pay for the shipping.

BE CAREFULL adjusting the carb "to spec" as this is not a spec boat anymore. if you lean the engine out to much (by turning the screws in) and it is not jetted properly it will hurt the pistons. if you can find someone to tune the engine properly it will be to your benifit in the long run