300/440/550 Questions after first ride

I had my 1987 js550 out on the water for the first time tonight and have a few questions. I was wonder what people set the jets at, i found by changing them the engine ran alright or crappy i couldn't find a good spot. It ran alright for a few minutes than would tend to just lose power and die, any thoughts? also I found it was over heating after taking it home i found the lines full of sand, i presume this is just from being to close to the beach when starting it. Also i was wondering how powerful these engines are supposed to be like will they pull you up good or are they kinda pitiful. I tested the compression and i had just over 120 psi in both cylinders so i don't think thats my problem. next time i think i will lean out the gas a bit and see if that helps as well. Any help getting the ski into tip-top shape would be much appreciated.
 

Hilli

S'Koolin'Em!;{-
Location
S.MI. / FL.
I don't know what your engine set-up is(pipe,carb,etc.)and I can't remember seeing a thread on that topic lately, if no one else posts you can always go to "Search" and punch in "jetting".I'm sure most of the threads will be on SJ's, hope this helps. T.
 
Backflush the cooling lines to get the sand out. Your performance problems sound like they're related to overheating, but they could be related to other things as well. There are some good carb tuning tutorials floating around if you search here or pwctoday. You'll have to read the plugs to tell if you're tuned right.
 

professor961

Selling all X2 and 650 parts - message me!
120 sounds like an old tired engine, and may be time for a rebuild. I also agree that you need to disconnect the lines from the exhaust manifold and blow out the sand from the lines. You probably have a blockage somewhere. As for jetting, you'd have to let us know what low and high jets you are running. If you are talking about the high and low screw adjustments, well, let us know where your screws are. Also tell us the type of carburetor.
120 PSI is gonna take a bit to get you up, but alot of the riding on JS hulls is finesse anyway.
Let us know more information. Best wishes.

Prof
 
120 sounds like an old tired engine, and may be time for a rebuild. I also agree that you need to disconnect the lines from the exhaust manifold and blow out the sand from the lines. You probably have a blockage somewhere. As for jetting, you'd have to let us know what low and high jets you are running. If you are talking about the high and low screw adjustments, well, let us know where your screws are. Also tell us the type of carburetor.
120 PSI is gonna take a bit to get you up, but alot of the riding on JS hulls is finesse anyway.
Let us know more information. Best wishes.

Prof

I am unsure of what the carb is and the jets that are in it, i just bought the ski and am kind of stumped on what it has in it. it seems like it was pieced together at somepoint as parts don't seem to match up with the year that i have been told that it is.
 
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