yamaha jet ski (I know its a ski but please help) - The Hull Truth

Striper Hunter 1979 · 08-07-2007, 10:49 AM

well i have a 2000 yamaha gp 1200r 3 cyl. jet ski that i use around the dock a lot when we are just hangin out there.i used it yesterday and it lossed a lot of power, when i take off it sounds like it is running on 2 cyl. it will only go about 35,if i hold it full throttle after about a 1/4 mile it will then kick in and take off to 60 mph.i idled by a long set of docks went to take off and it was running perfect but then i let off and it goes right back to the same symptoms.also when the problem occurs the warning light comes on for a hot catylitic converter.i would not ask for jet ski help on here but these things are so dam expensive to fix.please any help would be great,Randy

jeffro22 · 08-07-2007, 11:51 AM

would start with the simple things first. Change the spark plugs and fuel filter/ water serperator. if taht doesn't fix the problem you could try draining the fue

HardLivin · 08-07-2007, 12:06 PM

Had similar symptoms on a Yamaha Wave Raider minus the warning light. Changed the plugs and back in business.

Rude1 · 08-07-2007, 12:22 PM

The catalyst is most likely becoming hot due to excess unburned fuel in the exhaust creating an excessive amount of afterburn. So that being said you are probably losing ignition to one cylinder thus richening the exhaust. I would bet one of the coil's is bad. They are probably off the shelf automotive coils and you could have them tested at an Advance, Autozone type place to determine the bad one. Spark plugs rarely fail intermittenly as you are describing, but it wouldn't be a bad idea to replace them as well.

Striper Hunter 1979 · 08-07-2007, 02:56 PM

i did change the plugs,rude i think that is what it is i know one of the spark plug boots is electrical taped but i didn't think that was it.it was like that when i bought it.

paulyjsob · 08-07-2007, 05:12 PM

I had a 2001 GP1200R. They were notorious for cat problems. they would break apart and clog the exhaust. It seems like that's your problem.
Look around for a D plate. Its made to replace the cat while creating the same amount of back pressure.
You'll also need a chip into fooling the computer that the cat is still there. Otherwise you'll get warnings. Total cost around $70.