Hi Gunk ,What size main jets is it carrying, maybe go 1 size bigger might help ,

 

They were rebuilt with standard Honda jets, can they be replaced without removing the carbs?

 

Sorry matey, the carbs would have to come off, the main jets should be 115 , but maybe a 120 jet could work, what was the exhaust you have on, does the stutter happen at WOT

 

Thought so

It’s running a standard air box and oem filter but has a full Micron system with removable baffle.

Don’t the two centre carbs have a different sized jet?

I’m now wondering if it could be an electrical problem, before I pull the carbs off I’ll check all the plugs and leads

 

Hi Gunk ,sorry matey the jet sizes are 135 1&4 and 138 2&3 , the idea being to cool down the centre cylinders with more fuel, but I'll bet the jets are all the same size, the telling truth would be at wide open throttle through the 5000 to 6000 rpm if you get that stutter at WOT then its jet size, any stutter before that will be jet needle taper. although expensive, to get it right, have you thought about getting it Dyno'd, that will show where the problem is

 

I’ve now gone as far as I can go with it, you’re right next stage is to get it on a rolling road and Dynojet it properly

 

Hi Gunk, it would be a shame not to , after all you've done to the bike, this would be the crowning point, and a great stable mate for your other bike, tis a dark art getting the carbs right and having the equipment and time to do it makes it tough to get right, whereas the Dyno lads can sort it no problem and hand you back an even better bike

 

Even Mrs Gunk agrees that I should get it sorted out, the bike is now in such good original condition and there are so few good bikes left on the road, it would be a sin to just give it away.

 

Your missus is a very wise woman indeed, I think you know what you have to do.Bill

 

I had an interesting chat with a Dynojet dealer yesterday, he thinks it’s the full Micron system which is causing the problem and rejetting could help but is unlikely to solve it.

Ive got the original silencer in the garage, I just need a good used set of down pipes. I think that is the direction I’ll go in next. I hate the Micron pipe anyway!