Running issues when warm

[Dannyk]

Ok, here goes.
Recently, bike keeps running rough as soon as it gets warm, almost as if firing on 3 cylinders.
Steps taken to try cure this as below

New plugs - Nice bright spark
Carb off, cleaned, reset
airfilter cleaned
Coil tested
HT Leads replaced

Now, anyone got any ideas? Only seems to be when warm, under about 4k revs. If i let it die, will not start until it cools down, then as if nothing has happened.

Currently got redex in tank as well, to see if that could solve anything, but no joy as yet

Any help appreciated

Regards

[cargo]

To be honest that could be almost anything.............................

I had something similiar and it turned out to be the wires from the ignition pick up breaking down.................the insulation had become hard and brittle and the wire was partially broken. But it only caused a problem when it was warm/hot.

[Dannyk]

Tried all the electrics i forgot to mention, also removed the plug (and put it back) to remove water from airfilter box

[cargo]

The broken wire I mention was inside the cover.........it wasn't imediately obvious

[Dannyk]

Ok, will check that one then

Anyone anymore ideas?

[Dannyk]

Any ideas guys?

[lewisdale]

choke sticking? dodgy coils? just one of them things where you will have to just try and test one thing at a time till the prob is cured

[Dannyk]

Borrwed my mates bike now, so decieded on some TLC, head off, shimming, cam chain job lot, also going to carbtune it, anyone any experiance with the Gunson carbtune?

[zimm]

sounds like tight valve clearances tbh ..

do you mean "morgan carbtune" or "gunson colourtune" ?

the carbtune is ok, colourtune isnt much cop imho

[extonyg]

ye i would agree with zimm as i had this on my bike and because it was left too long it damaged a couple of rocker arms so i had to replace them so i would get checking those valve clearances but a engine rebuild is a good idea with new cam chain etc

[Dannyk]

Mean both, am going to balance and check mixture while i at it, carbtune for mixture got to be better than the try and see method??

[zimm]

carbtune is for balancing .. set the mixture by engine response