feels like fuel starvation ?

[AMCQ46]

OK, I have got a problem with my bike that can be best described as feeling like fuel stavation when it is running at higher throttle openings for longish periods of time ... looking for some suggestions as to where to look next.

the bike goes fine through the gears and pulls as hard as it ever did all the way up to the redline, but if I am sitting at 80+ for more than a minute or two, it feels like it is running out of petrol, loses power and feels flat. if I shut the throttle & pull in the clutch it drops to idle and still runs fine, and when I wind the throttle back on, for a moment it is OK, then it goes flat again. In the twisty bits is never shows its self as you are on and off the throttle.

So when I got home I pulled it apart expecting to find the tank vent pipe trapped or something like that, but they were all fine.

What I did find was the sub filters for the diaphragms were disintegrated and the plug closing off the front Vac pipe had fallen out ... everything else looked normal!

for me, I don't see how either of those could cause the problem, so what else could be ????? Petrol tap diaphragm was my next thought, so can somebody advise where to get a good quality service kit?

[Pete.L]

OK, I have got a problem with my bike that can be best described as feeling like fuel stavation when it is running at higher throttle openings for longish periods of time ... looking for some suggestions as to where to look next.

the bike goes fine through the gears and pulls as hard as it ever did all the way up to the redline, but if I am sitting at 80+ for more than a minute or two, it feels like it is running out of petrol, loses power and feels flat. if I shut the throttle & pull in the clutch it drops to idle and still runs fine, and when I wind the throttle back on, for a moment it is OK, then it goes flat again. In the twisty bits is never shows its self as you are on and off the throttle.

So when I got home I pulled it apart expecting to find the tank vent pipe trapped or something like that, but they were all fine.

What I did find was the sub filters for the diaphragms were disintegrated and the plug closing off the front Vac pipe had fallen out ... everything else looked normal!

for me, I don't see how either of those could cause the problem, so what else could be ????? Petrol tap diaphragm was my next thought, so can somebody advise where to get a good quality service kit?

I was thinking fuel tap too as my first thought. But what colour are the plugs? A rich problem could give you the same symptoms. Possible diaphragms or a hole in you vacuum pipes???


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[popkat]

The fuel cap vent is a tiny hole in the cap, try opening the cap so it rests but doesn't close and go for a ride to see if it's better*, I've had customers with the same problem on other Honda's and it's been the cap vent.


*obviously not with a full tank of juice


.

[AMCQ46]

cheers Malc, I will go look at the cap now

[bazza696]

you know this is an upgrade opportunity, to get a aprilia tuono

[Steve97]

Al.....its the Diaphragm, i had exact same problem same symptoms.

[AMCQ46]

Al.....its the Diaphragm, i had exact same problem same symptoms.

thanks Steve, that a great confirmation.........any recommendations where to get the best service kit?

[Steve97]

Al.....its the Diaphragm, i had exact same problem same symptoms.

thanks Steve, that a great confirmation.........any recommendations where to get the best service kit?

pop round ,erm, and ill give you one .........cough

[kevg]

when did the problem start? have you had the tank off?

i've not been near a firestorm in 8 years but if i remember rightly the rubber hose from the bottom of the tank has a tendency to kink slightly and could also cause starvation. worth a look when your doing the diaphragm.

[AMCQ46]

Kev,
the bike was fine on the Yorkshire run, and the only thing I did to the bike after that was wash it, and i did check that the ends of all the vent pipes were all clear after the symptoms started showing, and that made no improvement.

Steve, I only read your kind offer last night, but I already put an order in for a new one... but thanks for the offer

[lloydie]

Tank breather clogged be my first guess (give it a good blow job )
Have you still got the air deflector tray fitted under the air box ?
I found with it removed too much air was forced into the box and upset air flow .

[AMCQ46]

breather has been checked now and the under tray is still there.

diaphragm kit arrived now, so will fit that and retest

[sirch345]

breather has been checked now and the under tray is still there.

diaphragm kit arrived now, so will fit that and retest

Fingers crossed that does the trick,

Chris.

[Steve97]

Kev,
the bike was fine on the Yorkshire run, and the only thing I did to the bike after that was wash it, and i did check that the ends of all the vent pipes were all clear after the symptoms started showing, and that made no improvement.

Steve, I only read your kind offer last night, but I already put an order in for a new one... but thanks for the offer

no worries mate you know where i am if you need anything else

[fabiostar]

Al my yellow one done that for a while a month or so ago. started just after i filled it up at tescos... shity fuel so i drained it, cleaned the carbs and away it went fine ..