Loosing Power

[SouL]

Not bends in fuel lines, bends in the road (the lean angle of the bike)

Wondering if removing the rubber diaphram from the fuel tap completely and blocking up the suction nozzles on the valve may just solve the problem

[Neosophist]

Ye I saw that but I never had this problem before and it's only recently I take it you talking about the bends in the fuel line?

Not bends in fuel lines, bends in the road (the lean angle of the bike) . Because you've done the HRC fuel tap mod, it is no longer a vacuum fed fuel system - it is now gravity fed from the tank to the carbs. If you haven't had the problem before, it's logical that it's most likely the modified fuel tap causing the issue

I was under the impression their all gravity fed?

All the vaccum from the engine does is keep the diaphram open to allow the fuel to gravity feed into the carbs. i.e. it 'sucks' the fuel tap switch open.

As far as I was aware the HRC mod was done because the diaphram partially restricts the fuel output, so removing it all together allows a higher degree of fuel flow.

I don't see how it could vaccum feed?

[skinnydog0_0]

I was under the impression their all gravity fed?

All the vaccum from the engine does is keep the diaphram open to allow the fuel to gravity feed into the carbs. i.e. it 'sucks' the fuel tap switch open.

As far as I was aware the HRC mod was done because the diaphram partially restricts the fuel output, so removing it all together allows a higher degree of fuel flow.

I don't see how it could vaccum feed?[/quote]

As far as i am aware, they are gravity fed.
It might be worth taking the tap apart to check that everything is as it should be.
Also have you blocked the vacume point on the intake on the head, as this will affect the running of that cylinder if it's open.

[superlite]

I was under the impression their all gravity fed? I don't see how it could vaccum feed?

You're right. What I was attempting to say is that the fuel tap is either vacuum operated (vacuum operated diaphragm with gravity feed - stock) or gravity fed alone (diaphragm removed - HRC mod). Sounds simple enough, but for some reason the vacuum has more of an effect than just opening the diaphragm - an HRC'd tap does not like running on a low tank (reserve). I can't say why, but all racer's I know running big jets (140+) have the same issue - which doesn't agree with the laws of physics if both tap configs are essentially the same, but passing slightly different volumes/velocities. Not a huge problem unless you're trying to run a light tank though proabably.

Personally, I wouldn't bother with the HRC mod on the road unless you're running some seriously big jets and need the extra fuel. Otherwise it's probably just a stop gap solution to another problem.

[vfrman]

Ye I saw that but I never had this problem before and it's only recently I take it you talking about the bends in the fuel line?

Not bends in fuel lines, bends in the road (the lean angle of the bike) . Because you've done the HRC fuel tap mod, it is no longer a vacuum fed fuel system - it is now gravity fed from the tank to the carbs. If you haven't had the problem before, it's logical that it's most likely the modified fuel tap causing the issue

I was under the impression their all gravity fed?

All the vaccum from the engine does is keep the diaphram open to allow the fuel to gravity feed into the carbs. i.e. it 'sucks' the fuel tap switch open.

As far as I was aware the HRC mod was done because the diaphram partially restricts the fuel output, so removing it all together allows a higher degree of fuel flow.

I don't see how it could vaccum feed?

That is correct. The only thing the vacuum from the motor does is open the fuel tap to allow fuel to flow from the tank to the carbs, using gravity.

I am wondering if that fuel filter you put inline is causing enough resistence to keep the fuel from reaching the carbs when the level drops.

[spooky]

Yep you could do with it, it stops rust / sandy crap getting in the carbs and blocking the pilot jets up.

If you take the hose off and put it in an empty container and turn the tap on does the fuel flow freely? .

Yup...Yesterday I rode the bike for over 10km's and then it started dying on me, I then stop the bike (on the motorway!) blow down the breather nozzle and bike rides as if nothing had happened

You could have a blocked tank breather pipe which is causing vaccumn lock on the petrol.. try unscrewing the little breather off the top of the tank and riding see how it goes.

I took the breather pipe of yesterday and blew through it fine same with the valve. I've taken the breather valve apart and all seems fine. But will take your advice and leave the hose off. I've also fitted a smaller fuel filter as I was previously I was using a car filter and it was slightly too big causing the fuel hose to bunch up beneath the tank.

Like bunch up and kink the hose maybe.

[SouL]

I am wondering if that fuel filter you put inline is causing enough resistence to keep the fuel from reaching the carbs when the level drops.

I would really like to keep the filter on...none the less if it keeps on with this problem the next move would be to remove the filter. After all why put one on if the bike was never manufactured with the need of one?

[vfrman]

After all why put one on if the bike was never manufactured with the need of one?

Exactly.

[SouL]

Fuel problem came back again so have no popped off the fuel filter and removed the plastic inners from the air inlet valve on top of the tank lets see what happens...stand bye

[SouL]

Ok guys well looks like I have done every thinkable thing to solve my problem and trust it that the last idea I had of resolving the problem worked (so far) Basically I removed the entire inners in the fuel tank valve and seal it back up to insure no petrol leaks out and then removed the fuel filter which I installed and shortened the fuel hose in the carbs so that it had no loops in it. My guess is that the fuel filter causes the problem none the less two tank of petrol later and bike hasn't cut out on me