Carbs

[DougErickson]

Working on the sprint again, the old carb was a lost cause so I got a mikuni for it, made a little adapter ring and put it on. It started right up and ran great. But... my concern is that the carbs on these things sit at about 30 degrees off horizontal. Is this a problem? should I change the float height? It would be pretty challenging to get the carb near horizontal and be able to fit in an air cleaner too but I could probably do that if necessary. Any input? Thanks, Doug

[ATinkerer]

Doug:

If it runs, and doesn't overflow fuel from the bowl vent, I think I'd leave work on tuning it as is.

Quite a few MC carbs are symetrical with jet and needle positions on the centerline of flow through the carb. That makes them relatively tolerant to mounting angles.

If you have to make an angular correction, I'd try tapering your adapter ring into a pie shape.

Gordon

[salt-racer]

Hi Doug, I agree 100% with Gordon. I would try and tune it as 'it is' before anything else.

George

[DougErickson]

yeah thanks fellas, that saves me a lot of agony

[John H]

Doug,
Which Mikuni are you using? I would guess that the float level change from 0º to 30º could change the fuel level by
as much as 1/16 or more. Maybe no effect at all. The Amal GP's and Dellorto SS1's with remote floats are touchy about
getting the float level just right. I like to use a clear vinyl tube that's connected to the bottom of the bowl to hold up
for fuel level inspection.

[John H]

Here's some old racing carbs I'm restoring for my next project. They were originally set up for alcohol but will be set up
for gas. So new slides, needles and jets are on the way.

Amal TTs.jpg (218.87 KiB) Viewed 7763 times

[DougErickson]

30 mm mikuni, I like the clear tube idea and will have a dig thru the GPP (giant pile of parts) and see if If can make up the necessary pieces