Stumbling at 5000 rpm petcock question

[grytvikken]

Hi all I have an old 97 model vtr1000 thats been sitting a bit over the last few years
It idles ok but when you ride it , it stumbles badly around 5000 rpm. At first I thought it might be a carb issue but as I have already pulled them out and cleaned them as a precaution against old varnished fuel I feel it may be something else.
At the moment I am looking at the petcock with some suspicion.....I have the tank and fitted a hose to the vacuum and sucked .....hazaar fuel flows out of the petcock.....I stop sucking and the fuel more often than not continues to flow. I pulled the petcock apart and had a look and found nothing too bad it all seems ok. Should the fuel stop immediately from flowing once you stop applying vacuum? I am wondering if at 5000 the bike is getting too much fuel and is struggling because of that
Any ideas as to my theory would be gratefully received. Cheers

[tony.mon]

What are the plugs like?
When the vac stops the fuel should cut off, so something wrong with the tap, but the float needles in the carbs should prevent excessive overfilling, so I don't think that's your problem.

[sirch345]

What are the plugs like?
When the vac stops the fuel should cut off, so something wrong with the tap, but the float needles in the carbs should prevent excessive overfilling, so I don't think that's your problem.

I agree with Tony, something not right with the tap, but it shouldn't be overfilling at the carbs.

Are you sure the carbs are re-seated properly on the inlet stubs, and have you checked the hoses for splits or holes causing a vacuum leak

Chris.

PS. Welcome aboard by the way

[StuartWags]

have you had the cct done and accidently timed it out by 180 degrees?

[grytvikken]

have you had the cct done and accidently timed it out by 180 degrees?

Thanks for responses spark plugs are new I considered that. the cct IS cam chain tensioner? no its not been touched just had the bike sitting for awhile will check the carbs are seated correctly

[sirch345]

have you had the cct done and accidently timed it out by 180 degrees?

Thanks for responses spark plugs are new I considered that. the cct IS cam chain tensioner? no its not been touched just had the bike sitting for awhile will check the carbs are seated correctly

On the odd occasion it has been known for a new spark plug to be faulty,

Chris.

[grytvikken]

have you had the cct done and accidently timed it out by 180 degrees?

Thanks for responses spark plugs are new I considered that. the cct IS cam chain tensioner? no its not been touched just had the bike sitting for awhile will check the carbs are seated correctly

On the odd occasion it has been known for a new spark plug to be faulty,

Chris.

No mate it was doing it before I put new plugs in.

[Wicky]

Are you sure the carb isn't still gummed up from storage?

[tony.mon]

It's an easy check, swap carbs with a nearby owner to check it.

[grytvikken]

I guess its always a possibility that they are still gummed up up i was pretty sure i cleaned them well.....I dont have another set of carbs to swap them over ....

[Pezed]

Hi. Have you sorted this yet? I hope so, and if yes, then it would be good to hear what it was. If not, it does sound like a blocked or gummed up jet to me. I have known on another bike of mine, where removing the brass jet is not actually the jet at all, but merely an elongated cover, which, when removed, allows the jet proper to be removed by applying pressure from above. Caught me out first time because I don't have the manuals! Anyway, just sayin that's what happened to me.