Pissing fuel after standing for nearly 2 years

[Mike TW9]

Hi folks, any advice please?

Having been off the road since Dec 2020 & only started a few times during that period, the bike starts & can run normally for minutes, but pisses the contents of the tank onto the floor & conks out (I think when it runs out of petrol). The leak is a proper flow & comes not directly from the tank or petcock, but from below the airbox, approx. midway between the two cylinders & carbs when you look from the side.

I'm no real mechanic but the fact that it runs ok for a bit suggests to me that it isn't a stuck carb float or split/disconnected fuel pipe (I tried tapping them with a hammer at one point just in case)? I'm wondering if it could be a petcock issue with the leak coming from an overflow pipe? Or something else entirely? I did take the tank & airbox off to get a better look but TBH I didn't gain anything from it.

Grateful for any advice on what to do/try next!

With thanks in advance,

Mike

[sirch345]

It's possible that one of the needle-valves that regulates the flow of fuel is not closing off completely as the float rises with the carb filling with petrol hence it spilling out. The over filling of petrol in that carb could be choking that cylinder causing it to stall. Check first though all fuel lines for splits etc before delving into the carbs,

Chris

[Pete.L]

My thoughts exactly.
If the petcock was gone it would be leaking all the time or not flowing at all.

Pete.l

[Mike TW9]

Thanks Chris & Pete!

Guess I'll work on that basis then, will update when I get round to it.

Cheers,

Mike

[sirch345]

Thanks Chris & Pete!

Guess I'll work on that basis then, will update when I get round to it.

Cheers,

Mike

Good luck with it,

Chris.

[Mike TW9]

So I got round to removing the carbs yesterday and am pretty damn sure that the fuel was pouring out of one of the two short air vent tubes that come from each carb and end in between them. I think that means Chris's theory about one of the needle-valves not closing off completely is probably the problem. So I've done a bit more research...

Looking at the service manual (http://www.mediafire.com/?5u5qsfqgh9f9ejg, p80-83), the needle valves are accessed via the vacuum chambers and you don't need to separate the carbs to get to them. Replacement parts (Honda VTR1000F Firestorm SC36A UK/EUR '97-03 Needle valve Float Valve) are £12 each here: https://nrp-carbs.co.uk/shop/index.php? ... ct_id=3581. So if I order two of these follow the service manual and manage to put it all back together, fingers crossed I should be all right, right?

I'd really appreciate a bit more comment from anyone with a bit more experience of these things before I steam ahead. Are there other possibilities I should be looking at while I've got the carbs off? And should they be cleaned? (Freeride Nick said yes in a separate recent chain so I guess that's the answer: https://www.vtr1000.org/phpBB3/viewtopic.php?t=45549). I haven't got vacuum kit and if the work needed is much more involved than replacing the needle valves I may be looking at taking them to a shop. Maybe that's the more sensible option? I don't think it can be petcock issues judging by earlier comments, but could that cause an excess flow of petrol into the carbs, leading to it flowing out of the air vent tubes?

With thanks in advance for any semi-intelligent feedback!

[tony.mon]

Given your honest response and the amount of time it's taken so far it might be best if you get a shop to sort it for you.
It sounds to me like a diaphragm problem but could easily be a stuck float, either one is easily diagnosed by pulling the carbs off and having a visual inspection.
You should balance the carbs afterwards, any disturbance requires this, on these bikes, anyway.

[sirch345]

Given your honest response and the amount of time it's taken so far it might be best if you get a shop to sort it for you.
It sounds to me like a diaphragm problem but could easily be a stuck float, either one is easily diagnosed by pulling the carbs off and having a visual inspection.
You should balance the carbs afterwards, any disturbance requires this, on these bikes, anyway.

I'm inclined to think Tony's suggestion could be the best option.
My way of thinking is, the carbs really do need pulling apart to find out what the problem is before you go investing in parts,

Chris.

[Mike TW9]

Given your honest response and the amount of time it's taken so far it might be best if you get a shop to sort it for you.
It sounds to me like a diaphragm problem but could easily be a stuck float, either one is easily diagnosed by pulling the carbs off and having a visual inspection.
You should balance the carbs afterwards, any disturbance requires this, on these bikes, anyway.

Thanks Tony, I'll follow your good advice here, I learned the related carb balancing issue from the barber when getting my hair cut yesterday!

[Mike TW9]

Given your honest response and the amount of time it's taken so far it might be best if you get a shop to sort it for you.
It sounds to me like a diaphragm problem but could easily be a stuck float, either one is easily diagnosed by pulling the carbs off and having a visual inspection.
You should balance the carbs afterwards, any disturbance requires this, on these bikes, anyway.

I'm inclined to think Tony's suggestion could be the best option.
My way of thinking is, the carbs really do need pulling apart to find out what the problem is before you go investing in parts,

Chris.

Thanks again Chris!

[gavc]

Did you work out the issue? I have a similar thing with mine, also have petcock issues, so need to find one of them as well.

[Mike TW9]

Not yet I'm afraid, I've had the carbs cleaned & serviced but am now waiting for some better weather before reassembling the bike.

[purgeraptor]

Sometimes it's just debris under a carb float valve.
Gentle tapping of the carb body sometimes clears it.

If not, it's a carbs out job and clean up, or new float seats and valves.

[Mike TW9]

I got the bike back together last Sunday and was fairly confident it would fire up without leaking, but no sign of starting at all, then I saw a drip of petrol, despair! But I hadn't been sure whether the petcock was in the on position & after playing with that, success and no leaks! Idling very nicely but sounding a bit rough when revved, probably just needs carbs balancing.

So now I think it's a new rear light (Only 2/3rds of the LED working currently, I'll be in touch Mac), front tire, oil & filter change, carb balance & then MOT.

Thanks again for all the advice!

[sirch345]

I got the bike back together last Sunday and was fairly confident it would fire up without leaking, but no sign of starting at all, then I saw a drip of petrol, despair! But I hadn't been sure whether the petcock was in the on position & after playing with that, success and no leaks! Idling very nicely but sounding a bit rough when revved, probably just needs carbs balancing.

So now I think it's a new rear light (Only 2/3rds of the LED working currently, I'll be in touch Mac), front tire, oil & filter change, carb balance & then MOT.

Thanks again for all the advice!

At least you have it back together and running, well done

Chris.