@MIGHTYMAN couldn't comment other than its a round slide carb which is a no no for performance.

try adjusting air/fuel mixture this should help mate i had a similar problem with mine so got it cheap he thought it had bad problem. i will probably get around to buying after market crab as mine has a small crack on the carburettor body i have my tick over screw screwed in all the way

@MIGHTYMAN said in Is upsetting necessary?: 4FU from Germany. Not talking about the cylinder pal. Was talking about the Chassis/Engine code. Not that it makes too much difference but the 4DL's are ever so slightly different internally compared to the 3BN. Finding out it's a 4GW model will tell you what spec the engine was, I.E 4DL ran VHSA carbs over the 3BNs Mikuni TMX28. Stuff like that just tells you a bit more about the problem.

Yea tried the needle position when all was standard but the leaner I put it the worse it ran the richer the better but still didn't cure the hesitation. Thanks for the help.

Ah - thanks, now it starts to make sense. Been fiddling with it this afternoon and it seems to run great with a 260 main jet and 30 pilot jet - the only thing I wanted to achieve is reliabilty, making sure it not runs to lean, not to maximize performance..

Respect!

thanks callum the carbs all working fine now but cant seem to get the powervalve set right now...