a bit of spondoness.

[fabiostar]

this thing of mine when you get off a constant throttle is flying high up but roll of a little and it starts popping and banging and feels like its running outa petrol. whack the throttle and its a bit slow to respond then away it goes fine again. il have a look tho just incase.

i had it ticking over and sprayed easy start all round the carb stubs and didnt change revs so iv no air leaks .

[8541Hawk]

The running well at full throttle does make things a bit odd.
The rest of the symptoms kind of point to the pulse generator dying at an inappropriate moment just to cause you grief but shouldn't clear up at high revs.
Though you might want to run through the tests if you can....

[Stephan]

Isnt there any mechanical problem between buterflies and throttle? Seems strange and unlikely, but it is one of few things staying untouched when changing tank and carbs.

[Pete.L]

Well the pilot jets look after the bottom end and the main jet looks after the top end.
Could there be a leak in the vacuum circuit to the carb diaphragms???

Pete.l

[tony.mon]

It's sounding more like the vacuum not opening the fuel tap properly.
Check that there's no blockage in the vac spigot coming off the heads.

[8541Hawk]

Personally I do believe you have covered everything in the fuel system\carbs multiple times and might be time to focus on electrical\ignition issues at this point.

[fabiostar]

i changed coils,plugs ecu, pulled every singe electrical connection apart and checked and cleaned them..

i then tonight had a doner bike that arrived and i took carbs,tank etc of it, put them on the blue one, put all my blue stuff onto the yellow bike, the yellow one is flying and the blue useless piece of sh1t didnt run further than the end of the street before stopping this time. .

im afraid atm it wins, thats 3 sets of carbs,3 ecu units,coils. petrol tanks.anything i can remove from a bike to another bike has been done 3 times and its none the better. pretty it may be but its of no use to me im afraid..

now to decide what to do with it?

[freeridenick]

Have you given Roger a call? Worth a chat before you decide to dive into the engine. I can't see how it's not something it's ingested since before the new tank went on it was all good. Have you got a borescope?

[fabiostar]

Have you given Roger a call? Worth a chat before you decide to dive into the engine. I can't see how it's not something it's ingested since before the new tank went on it was all good. Have you got a borescope?

il maybe get around to it nick but at the min if i even look at it il take a gallon of petrol to it so its made its way to the garden shed were i cant see it for its own safety

[sirch345]

iv checked everything on the bike for the last 5 days. changed carbs,tanks. petcocks, coils,ecu leads,rec unit,battery. i mean everything that makes an engine run iv changed at least twice ,,,iv run outa ideas lads...

i changed coils,plugs ecu, pulled every singe electrical connection apart and checked and cleaned them..

i then tonight had a doner bike that arrived and i took carbs,tank etc of it, put them on the blue one, put all my blue stuff onto the yellow bike, the yellow one is flying and the blue useless piece of sh1t didnt run further than the end of the street before stopping this time. .

im afraid atm it wins, thats 3 sets of carbs,3 ecu units,coils. petrol tanks.anything i can remove from a bike to another bike has been done 3 times and its none the better. pretty it may be but its of no use to me im afraid..

now to decide what to do with it?

What about the Pulse Generator, have you checked it with a multi-meter or swapped this

I thought someone else mentioned the Pulse Generator, but I haven't found that post after a very quick look,

Chris.

[AMCQ46]

Compression test as it’s easy to do and eliminates something in the valves

[8541Hawk]

What about the Pulse Generator, have you checked it with a multi-meter or swapped this

I thought someone else mentioned the Pulse Generator, but I haven't found that post after a very quick look,

Chris.

[fabiostar]

as yet i havnt changed the pulse unit.. i went as far as checking the valve clearances and got the lend of a comp tester and alls good at the big lumpy engine end..

the only thing thats good if you can call it good is since using the yellow bikes carbs its got worse,which kinda points to fuel again..

one other thing it wont start on choke, if you pull the choke its slows the turnover of the engine.. but two choke cables on 3 sets of carbs cant all be broken? iv checked many times, not liking choke you would think would point to to a rich condtion yet it takes the choke once the engines warm and running bad which points to a lean condition


can you see why this is driving me nuts

[fabiostar]

i dont want to count my chickens but see my other thread

[sirch345]

What about the Pulse Generator, have you checked it with a multi-meter or swapped this

I thought someone else mentioned the Pulse Generator, but I haven't found that post after a very quick look,

Chris.

I thought it was you, but could I spot it, no . I have just gone straight to it now

Chris.