Post by thehag71 on Apr 28, 2011 4:26:25 GMT -5
I bought this Jet ski about 3 years ago. I bought it because the price was right. Really right. It was built by a company out of miami through the 80's. Not a regular V hull, it has a catamaran hull. See pics below. When I got it home, I could get it to fire with starting fluid, but that was it. I checked the fuel tank first, and yep, it was about a third full of nasty stinky old fuel. Ok, no big deal, I put about a gallon of lacquer thinner in the tank and let it sit for a few weeks. That got rid of most of the really funky stuff. Well, it got rid of some of the funk, but really softened the rest, and then I made some scrapers out of wooden paint stirrers and got most of the rest out. I had an access hole about 1 1/2" diameter where the fuel level sending unit goes into the top of tank. So there wasn't a lot of room to work, but it actually worked out ok. Thank God the tank is only about 18" long and 12" deep.
While I was waiting for the lacquer thinner to do its thing and soften up the crud in the tank, I pulled the carb and rebuilt it, put in a new battery, replaced the spark plug wires, put in new spark plugs, replaced all of the fuel lines, and put in a fuel filter. Fired it up and runs great. Woo Hoo! I am going out on the jetski this weekend! NOT! Got to the water, started jetski, runs good on trailer, put it in water and still running great, get about 300 ft. from shore and when I try to give it any amount of gas, it starts to run awful. So it runs great at all speeds on trailer, but as soon as engine has load on it from being in water, it runs awful at anything more than idle. WTF? Of course, I have my girlfriend on the back cuz I thought we were going to have a blast.
We still did have a blast, but it wasn't because of the Jet ski. 
Next week, I am double checking everything , and it all looks ok. Hmmm, Whats going on? Spark? Nope, nice and strong looking and nice and blue. Fuel? Nope, while cranking, fuel filter is full and doesn't seem to be any problem there, and when engine fires the filter is nice and full. (fuel filter is a clear one with replaceable filter elements) Compression? Nope. 141 psi on front cylinder, 142 on rear. Marine mechanic tells me to buy some stuff to de-carbon cylinders, heads, and exhausts, so I do. Runs great on trailer, get to water and same scenario. Runs great for a few minutes, but then starts bogging down, surging, almost not idling. I park it in my backyard, and kinda forget about it.
Fast forward about a year. Let's go out on the Jetski! Woo Hoo! Again, I pull the fuel tank, drain it and check if it is cruddy inside. It looks as new, so back in it goes, replace fuel filter element, make sure battery is charged and fire it up. Runs fantastic on trailer. Get to water, put it in, runs great, as soon as I give it gas, is running like crap again. Again, WTF?? Park it in backyard again for about another year.
Decide to sell it. Get a call from an interested party, wants to make sure it turns over. Ok, no problem, it turned over fine last time. Hook up battery and hit switch. CLICK. Won't turn over. Hook jumper cables up, still CLICK. I figure it is the starter. Call buyer back and explain. He is cool about it, says let him know if I get it running. Pull the starter out and dis-assemble. Looks great inside. Lube up shafts/bearing and re-assemble. Hook up battery on bench and starter is spinning great. Install starter into engine, hit key and just CLICK. NO SPIN. OK, rings stuck to cylinders from sitting, no problem, Pull the plugs, put some liquid wrench into cylinders, pull front cover off of engine, put socket and breaker bar on crank nut and try to turn. NOPE!! Well looks like I am not selling it just yet, might as well pull engine and fix it.
While getting ready to pull engine, I start doing some research on the engine and what kinds of replacement parts are available for it. Everything I might need is available. I also do some research on the carb that is on it. Turns out that the carb has a fuel pump built into it that runs off engine vacuum. When I originally rebuilt the carb and replaced fuel lines, I had put all of the fuel lines and vacuum lines back in their original locations. I know I did because I took a bunch of pictures of them and labeled everything before I removed it. While doing the research on the carb, I start really looking at the cutaways and how the fuel pump works and the fuel flows. YEP, someone before me had reversed the fuel inlet hose and the fuel pump vacuum hose, which means that the carb wasn't working correctly from the time I got it, which was probably the cause of my poor running under load problem. Maybe not though.
I pulled the flywheel off while dis-assembling the engine and I found the magnets inside of it were not attached to the flywheel anymore, they were all bunched up together with no space between them. (the engine doesn't have points, it is c.d.i.) So, I am at the point of not knowing whether it was the spark plugs not getting spark at the correct time, or if it was that the fuel pump vacuum and the fuel inlet lines were switched as to what was causing the problem with the engine running poorly under load, or if it was both of those problems causing the engine to not run properly. Either way, it is gonna be right when I am done in about 2 weeks and if I still cant get it to run right, I am scrapping the jetski and making a small utility trailer out of the jetski trailer.
While I was waiting for the lacquer thinner to do its thing and soften up the crud in the tank, I pulled the carb and rebuilt it, put in a new battery, replaced the spark plug wires, put in new spark plugs, replaced all of the fuel lines, and put in a fuel filter. Fired it up and runs great. Woo Hoo! I am going out on the jetski this weekend! NOT! Got to the water, started jetski, runs good on trailer, put it in water and still running great, get about 300 ft. from shore and when I try to give it any amount of gas, it starts to run awful. So it runs great at all speeds on trailer, but as soon as engine has load on it from being in water, it runs awful at anything more than idle. WTF? Of course, I have my girlfriend on the back cuz I thought we were going to have a blast.
We still did have a blast, but it wasn't because of the Jet ski. 
Next week, I am double checking everything , and it all looks ok. Hmmm, Whats going on? Spark? Nope, nice and strong looking and nice and blue. Fuel? Nope, while cranking, fuel filter is full and doesn't seem to be any problem there, and when engine fires the filter is nice and full. (fuel filter is a clear one with replaceable filter elements) Compression? Nope. 141 psi on front cylinder, 142 on rear. Marine mechanic tells me to buy some stuff to de-carbon cylinders, heads, and exhausts, so I do. Runs great on trailer, get to water and same scenario. Runs great for a few minutes, but then starts bogging down, surging, almost not idling. I park it in my backyard, and kinda forget about it.
Fast forward about a year. Let's go out on the Jetski! Woo Hoo! Again, I pull the fuel tank, drain it and check if it is cruddy inside. It looks as new, so back in it goes, replace fuel filter element, make sure battery is charged and fire it up. Runs fantastic on trailer. Get to water, put it in, runs great, as soon as I give it gas, is running like crap again. Again, WTF?? Park it in backyard again for about another year.
Decide to sell it. Get a call from an interested party, wants to make sure it turns over. Ok, no problem, it turned over fine last time. Hook up battery and hit switch. CLICK. Won't turn over. Hook jumper cables up, still CLICK. I figure it is the starter. Call buyer back and explain. He is cool about it, says let him know if I get it running. Pull the starter out and dis-assemble. Looks great inside. Lube up shafts/bearing and re-assemble. Hook up battery on bench and starter is spinning great. Install starter into engine, hit key and just CLICK. NO SPIN. OK, rings stuck to cylinders from sitting, no problem, Pull the plugs, put some liquid wrench into cylinders, pull front cover off of engine, put socket and breaker bar on crank nut and try to turn. NOPE!! Well looks like I am not selling it just yet, might as well pull engine and fix it.
While getting ready to pull engine, I start doing some research on the engine and what kinds of replacement parts are available for it. Everything I might need is available. I also do some research on the carb that is on it. Turns out that the carb has a fuel pump built into it that runs off engine vacuum. When I originally rebuilt the carb and replaced fuel lines, I had put all of the fuel lines and vacuum lines back in their original locations. I know I did because I took a bunch of pictures of them and labeled everything before I removed it. While doing the research on the carb, I start really looking at the cutaways and how the fuel pump works and the fuel flows. YEP, someone before me had reversed the fuel inlet hose and the fuel pump vacuum hose, which means that the carb wasn't working correctly from the time I got it, which was probably the cause of my poor running under load problem. Maybe not though.
I pulled the flywheel off while dis-assembling the engine and I found the magnets inside of it were not attached to the flywheel anymore, they were all bunched up together with no space between them. (the engine doesn't have points, it is c.d.i.) So, I am at the point of not knowing whether it was the spark plugs not getting spark at the correct time, or if it was that the fuel pump vacuum and the fuel inlet lines were switched as to what was causing the problem with the engine running poorly under load, or if it was both of those problems causing the engine to not run properly. Either way, it is gonna be right when I am done in about 2 weeks and if I still cant get it to run right, I am scrapping the jetski and making a small utility trailer out of the jetski trailer.
