99 yamaha gp 1200 stalls.Advice?

[Zeebo]

Last year I took my 99 gp1200 out and it wouldnt reach full speed and it would just die.The engine wouldnt even turn over at all for about 30 seconds after it died,then it would start up and run but again once I got to half throttle it died the same as before.Since it wouldnt even turn over for several seconds makes me think its something electrical.Any suggestions?


Thanks,

 

[Jeff Walkowiak]

Re: 99 yamaha gp 1200 stalls.Advice?

check the ground strap from the battery to the engine block,, be sure it is a clean conection and the cable is in good condition

 

[Zeebo]

Re: 99 yamaha gp 1200 stalls.Advice?

I havent checked that yet.Thanks.It happened late last season and I didnt get a chance to go through it yet.Im planning on new spark plugs,fuel filter,etc before I take it out for a test run.

 

[twista]

Re: 99 yamaha gp 1200 stalls.Advice?

you can check the connection,, but the fact that it starts 30 seconds later tells me that is not the case!,, you stuck the motor,, meaning that it welded its rings to the wall BECAUSE,, either you have an air leak somewhere or lack of oiling ie. dirt in the oil pump lines etc.. i always do away with the pump and pre mix thats the only way to go,, time for a rebuild sorry,, probably be able to just do the one piston.. make sure to use 1211 3 bond on the rebuild so it is air tight and you wont have the problem again for a while!

 

[Zeebo]

Re: 99 yamaha gp 1200 stalls.Advice?

Im afraid you are right.After taking it for a quick test run during which it stalled.I discovered that one of the motor mounts is bad.This caused excessive engine vibration and the oil line feeding the #3 cylinder came off.Of course it was in an area that isnt easy to see.I ran a compression check and had 120psi in #1 and #2 cylinders,but only 35psi in cylinder #3. So it has a bad cylinder.

Now the question is will I just be able to replace the piston and rings or is the case damaged? Since I didnt run it for very long hopefully the damage isnt too bad.Further inspection will tell all.

If the case is damaged I can do an exchange with sbt for a new case and pistons for $700.I dont know if this option makes much sense because for another $300 I can get a rebuilt engine with a one year guarantee.

Has anyone out there done a top end rebuild or engine swap? If so how difficult was it and what advice can you give?

Thanks!!!