Engine not running right

[kyle frantti]

So i recently purchased a 1987 kawasaki 650sx. I put it on the water and it runs fine until i jump on it, and start riding it. Then it bogs right down and acts like its running on one cylinder. I have no idea where to even start since this is my first jet ski. Any ideas??

 

[Mdavies_02]

Have you checked the compression?

 

[Mike W]

Sounds like a fuel issue and could be several things. Check the fuel selector for any obstructions, fuel filter, water in fuel tank, and the carb internal filter. How long has it been sitting? The carb may need to be rebuilt as well.

 

[Pro-pulsion]

CDI, if it idles fine and then sounds like it drops a cylinder when you put it to work, or if it runs or has ran fine very recently but stalls after about 30 seconds of run time then the CDI is toast. It was the last thing I finally installed before I sold my 650sx after a full summer of chasing those issues mentioned. I checked everything other than the CDI, changed carbs, both freshly rebuilt, trimmed high tension lead ends, new plugs, new caps, cleaned every electrical connector and gave them dielectric grease...only to find out the CDI failed. If for some reason it ends up not being the CDI, having a back up in your parts inventory is always a very good idea. Also remember, when testing compression both plug boots should be grounded. The easiest way to do that is to just have a plug in each boot and decently secured to the engine...do this when checking the plugs for spark as well. Both plugs need to be grounded to the head or block. The reason being that the capacitors inside the CDI will swell and eventually burst if they can not discharge, the end result will be a failed CDI.

 

[kyle frantti]

Have you checked the compression?

I have not, but I start it up outside of water very briefly and it sounds like it's running on two, then I bring it to the lake and it sounds great right until I jump on and give it some gas, loads right up and barely moves, until I build some momentum then it seems like just one cylinder is firing because it just pours out white smoke

 

[kyle frantti]

CDI, if it idles fine and then sounds like it drops a cylinder when you put it to work, or if it runs or has ran fine very recently but stalls after about 30 seconds of run time then the CDI is toast. It was the last thing I finally installed before I sold my 650sx after a full summer of chasing those issues mentioned. I checked everything other than the CDI, changed carbs, both freshly rebuilt, trimmed high tension lead ends, new plugs, new caps, cleaned every electrical connector and gave them dielectric grease...only to find out the CDI failed. If for some reason it ends up not being the CDI, having a back up in your parts inventory is always a very good idea. Also remember, when testing compression both plug boots should be grounded. The easiest way to do that is to just have a plug in each boot and decently secured to the engine...do this when checking the plugs for spark as well. Both plugs need to be grounded to the head or block. The reason being that the capacitors inside the CDI will swell and eventually burst if they can not discharge, the end result will be a failed CDI.

Well It sounds perfect right until I put it to work yeah, then it loads up and will slowly gain speed and it's just pouring out white smoke

 

[Half flip95]

Check your starter. One time I got a starter that was wound the wrong direction. It ran left instead of right

 

[Pro-pulsion]

Well It sounds perfect right until I put it to work yeah, then it loads up and will slowly gain speed and it's just pouring out white smoke

You didn't mention that before, white smoke is water being boiled and leaving in vapor form. It now sounds to be either a head gasket leak or base gasket. Once you pressurize the cooling system the leaks if any will surface.