engine dies at speed

[Anonymous]

1983 gs750 e engine revs (wot) through gears 1-4very well, no problems at all .get into 5th still accelerating still wot then just slows way down, not a miss, no chugging just feels like i let off the gas.slow back down and bike feels fine.i know it could be quite a few things.the feeling i get is that it could be a piston trying to stick but then i`m not a bike mechanic (this all happens on my personal test track and not on any city,county or state roads ok )your input is greatly appreciated.thank`s Mark 8)

[Anonymous]

Dies at speed

Odd..... maybe you have run out of power! How much will it slow down if you hold it there? Does it slow down or just stop pulling hard? Sounds like you may be running lean. I mean the frist 4 gears go quickly so you aren't using so much fuel from the bowls. Are your floats set correctly? Maybe you need to raise them a pinch. Bob

[moto_dan]

Re: Dies at speed

Sounds like you may be running lean. I mean the frist 4 gears go quickly so you aren't using so much fuel from the bowls. Are your floats set correctly? Maybe you need to raise them a pinch. Bob

Good point. On the last Texas Hill country ride I had a similiar situation on my '83. The bowls were running out of fuel due to a partial clog in my petcock(fuel valve). Once I removed the obstruction the bike has run fine. You might try switching your petcock to prime to see if things change.

[Anonymous]

Will it hurt the bike to ride it with the petcock on prime? or is it only bad leaving it on prime when the bike is not running?
Tom

[moto_dan]

Will it hurt the bike to ride it with the pet#### on prime? or is it only bad leaving it on prime when the bike is not running?
Tom

Running it on prime will not hurt anything, but leaving it on prime while engine is stopped can cause problems.... example: if your needle seat valves(internal to your carb.) don't properly seal you can fill your crankcase full of fuel. Not good.

[SqDancerLynn1]

I wouldn't think it is the floats, the fuel system is not supplying enough fuel to the carbs, Make sure that you are using 3/8 fuel line
Check and clean the tank, petcock and the vent in the gas cap

[Anonymous]

Re: Dies at speed

Odd..... maybe you have run out of power! How much will it slow down if you hold it there? Does it slow down or just stop pulling hard? Sounds like you may be running lean. I mean the frist 4 gears go quickly so you aren't using so much fuel from the bowls. Are your floats set correctly? Maybe you need to raise them a pinch. Bob

the feeling is that i just lost 2 cylinders when the motor starts to die it is quite noticable.it`s not that it starts to run rough it just loses power the fuel starvation sounds reasonable and i will check into it i do appreciate yours and every one elses input on this matter.it`s not that it sees that speed very often but when ya want to go ya want to go.thank`s Mark 8)