Topic: Mikuni VM29 adapted to CB750 OEM inlet rubbers

[PeWe]

Good updates here
Don, how are your VM29's jetted now?
If you know:
# Needle jet size. (O-6 or O-8)
# Pilot
# Needle and clip setting
# Main jet

My set had needle jet O-6 when delivered 1983.

I saw many years later (29) reading Sudco catalog that CB750 should have O-8 so I changed.
That can explain the need of bigger pilot. I finally used pilot 25 back in 1984 due to the smaller O-6.

But the plugs sooted quickly. Only NGK D8EA that did not sooted to death very quick.

So bigger needle jet O-8 and smaller pilot 17.5 worked better 2014 when I used them again.
A bad ign wire tricked my jetting tests. Intermittent issues on one cylinder.

I have learned when jetting my TMR carbs that needle taper and needle jet are the most important part of jetting. If not matching, the jetting will never be correct, always wrong somewhere.

Good that the Sudco/UPP urethane carb adapters seems to work.

I remember mine delivered with carbs were very soft, pulsating when idling. Lots of visible cracks on outside within a few thousands km. Next rubber boots setup a few years later not better.

I updated my old post with VM29 jetting examples and parts list.

I plan to use my old VM29 carbs again on my slow ongoing CB750 build. Engine will get JE 890cc.

Case is opened to handle my billet block with JE 71.25 mm pistons, now updated with horisontal gas ports. I wonder how the top rings will wear...

Here the page 166 from latest Sudco catalog again.

[Don R]

 I didn't write down my jets because they matched the chart for cb750 with 29 smoothbores at the top of the other bikes section where it says Mikuni info from Z1. I've referred to that whenever I'd involved with Mikuni carbs.
 It helped me identify my brothers 26mm Kawasaki carbs, his friend was going to install them on a cb750 until he decided that his Honda carbs were bigger.