The cover over the actual valve has a bolt in it instead of the valve pulley.
If I blocked up the exhaust and just pulled away a few hundred yards might it behave?
The thing I don't get is when I last went out the bike slowed down to zero and would not rev above a lumpy tickover on full throttle and cut out when throttle was slightly shut? Can't see that happening just cos no exup?

Hi mate
I don't think a stuck or removed exup would cause all of this to happen,
Have you checked the fuel pump is pushing petrol out at a good rate? The pump has to stop after a few seconds after the carbs fill or it will be flooding the engine, maybe down to crap in the float valves.
Check that the tank cap air vent is not blocked,
You say the carbs have been cleaned out but how? I have set of what were very good carbs that blocked up over winter due to shit fuel left in them. They would not work properly even after many attempts with cleaner & air lines etc, you need to have them put in an ultrasonic cleaner if the tiny idle passage ways are blocked.

Also it's worth looking at the carb diaphrams to see if they are split and that the sliders are lifting when you rev the bike. If they are split the won't open up and will not let in enough air!
Hope this helps a bit.
Dobbs

Thanks very much! As I say fuel pump is fine going fast is no prob and I can say the carbs are clean
Cheers for your time!
Mark

Has it got fresh fuel in it? There might be some crud or water in the carbs.

Have you cleaned the carbs or are taking somebodies word for it ???

have you cleaned out the tank?

you can change filters and clean the carbs, flush the fuel pump etc but if the tank is full of sh*t then this will just keep happening

drain the tank completely and have a good butchers with a torch, if it's showing signs of rust or accumulated sh*t then remove the tap and fuel sender, make some plates to fit the fixings for both then seal with a bit of rubber and fill 2 to 1 with hot water and "B&Q no nonsense metal cleaner / restorer" it's a mild acid and bloody marvelous, leave for about 24hrs and rinse out well, (you dont need to fill the tank right up, about half way will do, then just give it a shake every now and again.) the rust is generally in the bottom and is caused by condensation forming above the fuel and then settling under it as it runs down the inside of the tank, another good reason to drain the tank if the bike is gonna be stood for any length of time

just as an after thought, once treated, if it's gonna be left empty for any length of time the tank will get a film of surface rust in it, so give it a rinse with the old 2stroke petrol mix, you don't need allot, 1/2 pint'll do, it just coat's it with oil and stops the rust

Thanks for advice, I think the tank is ok as after 5K it runs great and pulls like a good one!
Thanks again something else to add to the list!
Regards Mark

MarkT wrote:Thanks for advice, I think the tank is ok as after 5K it runs great and pulls like a good one!
Thanks again something else to add to the list!
Regards Mark

Thinking isn't the same as knowing

Actually, thinking about it, did the expert you bought it off mess around with the needle heights? You could try lowering them one clip to lean it out, and it's a cheap thing (free!) to try and easily reversible if it's wrong, or take the air filter out and try it with no filter.

Good points that's why I wanted to know standard settings as owner has altered the settings jets but assured me he had put it back standard
Mark

MarkT wrote:Good points that's why I wanted to know standard settings as owner has altered the settings jets but assured me he had put it back standard
Mark

I think we can both assume the previous owner is a bit of a fibber

I think what might have happened is that Jerry Burgess has removed the exup valve and changed the main jets, and possibly raised the needles as well 'for more power'. I can't remember off the top of my head what size the mains are as standard (but 100-ish rings a bell).

For a quick and dirty test to see if it is running a little rich, take the air filter out and see if that makes a difference.

Stick with it, we'll get this bike up and running as it should be