2000 yamaha GP1200r need help - PWC Forum: The best hang-out for Personal WaterCraft enthusiasts

yamaha1200 · 08-28-2011, 08:13 PM

just got a 2000 1200r this week and took it to the lake, it bogs down if you give it throttle from an idle speed if you bring it up to speed slowly until it is on top of the water it is fine and it works perfectly. then had trouble starting it and found two parts off laying in the hull and put them back on ( not sure what they were at the time but now know they were the power valve couplers) got it running for a quick spin and it still was bogging down at takeoff, so replaced the plugs and not starting again! so frustrated just started the sport this year and already have 2 skis with problems!

Ernest T · 08-29-2011, 05:03 PM

There are a number of possibilities from dirty carbs, to power valve failure (which was common on the 2000 model 1200 skis). I'd look at the carb problem for bogging. You may need to clean/rebuild them. I would also recommend a compression check to see if you have any piston/cylinder damage, before you try to run the engine much more.

yamaha1200 · 08-29-2011, 06:13 PM

are the carbs some thing that requires a lot of experience to check out im new at this, and if they are clogged will it be obvious, no worries on running it i cant get it to start. can any damage be done by running the ski with the power valve couplings off not sure how long they were off.

Ernest T · 08-30-2011, 06:42 PM

here is a carb. rebuild guide to give you an idea of the level of difficulity: http://www.shopsbt.com/pdfs/mikunisbn.pdf You can get the rebuild kit for around $50 or less, but you need one for each carb. You can have a dealer do the carb rebuild, but as you can see from the guide it can be a little labor intensive, so most dealers will charge $100-$150 per carb. for labor..........it can get expensive unless you do it yourself. This really needs to be done every 3 or 4 years or your going to have trouble (probably more often if you run ethanol containing fuel).

The engine will run without the power valves working, but you loose a fair amount of top end power. The problem on the pre-2003 1200 series skis is that the valve could drop into a cylinder and do significant damage = need to rebuild the top end or the entire motor. The solution is called a wave-eater clip: WaveEater Products So you need to find out if these or something similar has been installed on your power valves or not, and do the upgrade if needed.

I hate to add more bad news, but if that ski still has the catalytic converter, I'd look at getting rid of it as well and add a "D" plate. The cat/con is famous for failing after 10 years and causing more damage. Here is a site that has the clips and "D" plate: http://www.islandracing.net/gp1200r.html

Unfortunately, you could be the poster child for "New Owner of a 2 Stroke Ski". I wish I had a dime for every post about someone that had just bought a 2 stroke ski, and was now having problems with it............I'd be rich.

I'd advise all new potential ski owners to only look at 4 stroke models............2 strokes are yesterdays technology, and buying a used one is a crap shoot.

yamaha1200 · 08-30-2011, 08:30 PM

thanks for the info, im going to barrow a compression test tool from the local garage to check compression tomorrow, charging the battery tonight, also found today that the air intake hoses came off and were just laying in the hull not sure if that maybe causing some problems or not. The ski does have the "D" plate and chip

(one thing off the to do list) and it also has the oil block off kit. Did look into the wave eaters and will order them this week! hoping it will start tomorrow.

yamaha1200 · 08-31-2011, 01:04 PM

charged batery still wont start

did the compression test and the 3rd cylinder only has 45psi. i saw alot of posts stating that they had 0 pressure is there a different set of issues if you have low pressure vs no pressure?

Ernest T · 08-31-2011, 01:21 PM

Its always the 3rd cylinder. My guess is that either a power valve fell and messed it up. It is also very common to see an oil line come off this cylinder, but that is not a factor if you since you are running premix.

Best case would be that there is no damage to the crank or bearings, then you would just need to rebuild that top end or just that cylinder depending on the amount of damage. You will need to pull the head off and have a look to see what you have.