Bike stays running

[clayton00grand]

Got a bike in the shop to put in new pistons and rings. cylinder bored just a touch over to clean up, new gaskets. Anyway finally had time to finish it up tonight, I started it up and was tinkering around with the carb making sure they were tight and all before the ride. It still has factory TORS installed.. Anyway I started it up and put seat back on and , sat on it cracked the throttle a bit and then it kept running without me touching throttle. So I decided to turn off key switch, factory slide on the bars, and still running. Then I turned the gas valve off , and had some insulated pliers handy, so I yanked plug caps off and damn thing still running. So at that point I;m like well hmmmm. Finally it ran out of fuel and then died. What would cause this problem?

 

Thanks

Clayton

 

The reason for new rings and pistons to start off with was blow by ring was stuck in piston only like 50 psi.

 

 

So any thoughts anyone has please chime in. They want to pick up this weekend.

[278]

Let me get this right you pulled the plug caps and it still ran? The only thing i can think of like that would be its acting like a diesel engine and your compressionn is so high your spark plugs are acting like glow plugs... Id do a compression test, but if your compression is that high I dont think it would even start without high octane fuel

[350BANSHEE350]

well at first i thought maybe your compression was low, but i read on and obviously i have changed that first guess to the compression being to high, you must be preigniting, so the spark plugs are useless because the compression is high enough to combust the fuel before it needs a kick in the ass by the spark plug, did you give the machine shop your pistons that are going in it before they did the bore job, most places will match the pistons slightly to the bore job being done. my guess is that its to tight of a fit in the cylinders and compression is too high and youll need to have the machine shop bore i out a little more

[clayton00grand]

well at first i thought maybe your compression was low, but i read on and obviously i have changed that first guess to the compression being to high, you must be preigniting, so the spark plugs are useless because the compression is high enough to combust the fuel before it needs a kick in the ass by the spark plug, did you give the machine shop your pistons that are going in it before they did the bore job, most places will match the pistons slightly to the bore job being done. my guess is that its to tight of a fit in the cylinders and compression is too high and youll need to have the machine shop bore i out a little more

 

Yes who we have bore our cylinders we send them the jugs they send us cylinder and pistons back bore to match supposedly never ran into problem with them before. Could there be anything else. What I dont understand i started it up the first time tonight and it started very hard the carb tops were loose, after i got it running rode it around yard 2 times then noticed it kind sticking a bit. Shut off took off seat and looked on cap was completely loose/off i tightened it very tight prior to this. By no means am I second questing anyone just trying to figure this damn thing out. I myself have a shee and it has tors removed and different carbs and mine was rebuilt some years ago. mine still runs great..

 

Thanks again

[Bansh-eman]

you could have a carbon deposit that is creating a hot spot that is igniting the fuel, you could have a spot on the piston that has be getting burnt from running lean that is thin and getting hot causing fuel to ignite. there are a few things. i doubt the compression is that high that your motor is dieseling. you wouldnt be able to kick it over very easy if that were the case

[bansheesmoke]

The only time this happend to me is when I forgot to put my crossover tube back on.... And the lean condition caused it to keep running. Is your crossover tube on your carbs on with no airleaks?

[clayton00grand]

yES IT IS i TOOK OFF THE CARB BOOTS WITH THE BOOST BOOTLE LEFT ON IT NEVER DISASSEMBLED IT.