GP1200 run with no plug wires?

[Chris2]

Hi guys I need some help with my 1998 Yamaha GP 1200. I had it out the other day and everything was fine until a small hose that goes from the exhaust to the back of the cylinder head (on top) came off and filled the hull half full of water, it would still run after that but with little power. Got it home and found the hose, put it back on and it runs fine on the water hose but when I revved it up to 2500 to 3500 rpm (no tach) it wouldn?t idle back down, hit the stop button and it wouldn?t stop, pulled the safety lanyard and it still ran so then I pulled off all 3 spark plug wires and it still ran didn?t even slow down I had to turn off the gas to shut it down.
I?m assuming I got water in the carbs and that?s why it started running bad, that part seems to be fixed but I?ll have to put it in the water to find out for sure my big question is How did this thing run at speed with no spark plug wires?

 

[bigdaddypt]

Re: GP1200 run with no plug wires?

It's called glowplugging or diesiling. Basically, it got so hot that somethign in the cylinder was still giving off enough heat to ignite gas. Were you running water through it when this happened? An leak on the intake can cause this condition as well.

The way to get it stopped is to pull the choke and give it full throttle at the same time.

 

[Chris2]

Re: GP1200 run with no plug wires?

Yes I was running water through it when it wouldn't die and I had just started it cold when it did that.
I put it back in the water and it will not rev and runs better when choked, I pulled the fuel filter and got clean gas out of it but when spinning it over it will only put a very small amount of fuel back in the filter. I've always had to pore gas in the carb to get it started the first time and that seems to have gotten worse over the last two years if it sits for 20 min i have to pore more gas in the carb to get it to crank again. How do i test the fuel pump? I did check compression and got 121,124,122.

Oh and I'm not sure what turns on the fuel pump because most of the electrical dose not work, none of the dash instruments work the starter is just a button wired from the battery and the oil injection is also out have to pre mix the gas.
Thanks