By joining you will help ensure that we can continue to provide this service
JOIN HERE!
Rebuilding an F750
- Ericandchi
- Posts: 57
- Joined: Sun Oct 09, 2016 10:11 pm
- Been thanked: 3 times
Re: Rebuilding an F750
-
- Posts: 1
- Joined: Wed Dec 29, 2021 11:14 am
Re: Rebuilding an F750
Looks great! I've been following this build with your Dad since it started. We've had many hours of conversations about fine details. I'm pleased that the Wedgetail Ignition worked well for you. I was confident that it would, as it makes mondo bright spark, a real necessity when the long intake runners are taken off. I think a lot of custom builders will discover this going forward.
Please post some video with sound now that it runs! I can't wait. I was going to ride down to hear it start up, but with Hurricane Ian tearing up the Atlantic coast right now I figured that the riding might not be too pleasant. I hope to get down there before the bike leaves for TX, though. I'd prefer to see you when I get there but Ma Nature has a different idea.

Tom Cutter
Yardley, PA, USA
RubberChickenRacingGarage.com
WedgetailUSA.com
- Ericandchi
- Posts: 57
- Joined: Sun Oct 09, 2016 10:11 pm
- Been thanked: 3 times
- Ericandchi
- Posts: 57
- Joined: Sun Oct 09, 2016 10:11 pm
- Been thanked: 3 times
Re: Rebuilding an F750
https://youtu.be/cQNCT-ZnQiA
Ps, it's much quieter than the open pipes of past.
- Ericandchi
- Posts: 57
- Joined: Sun Oct 09, 2016 10:11 pm
- Been thanked: 3 times
Re: Rebuilding an F750
- Ericandchi
- Posts: 57
- Joined: Sun Oct 09, 2016 10:11 pm
- Been thanked: 3 times
Re: Rebuilding an F750
- Ericandchi
- Posts: 57
- Joined: Sun Oct 09, 2016 10:11 pm
- Been thanked: 3 times
Re: Rebuilding an F750
Turns out the Mikuni TM38 carbs were just too big and there was no way I was going to get them dialed in. The issue is the valves in the R65LS heads are too small resulting in too little airflow to get things moving. Even though the bike is an 860cc, the smaller valves proved too limiting. I went ahead and bought a pair of Mikuni VM34s which was on the original bikes which had R75 heads with 750cc displacement.
The result is everything worked right out of the box with just a little adjustment to the mixture screws. I haven't ridden the bike so some further adjustments may be needed but at least I know i can get there.
We have a set of R100 heads that might go on the bike someday, but for now i think it will be just fine for its intended usage.
I did move the chokes over from the TM carbs. I think the knobs look better than the stamped metal levers that come on the VMs. Luckily the internals are same on both carbs.
-
- Posts: 19
- Joined: Tue May 26, 2020 9:24 am
Re: Rebuilding an F750
I've run VM34's on our 750 racing sidecar for years they work well once
we got the jetting dialled in.
Mathew
- Ericandchi
- Posts: 57
- Joined: Sun Oct 09, 2016 10:11 pm
- Been thanked: 3 times
Re: Rebuilding an F750
https://speedmotoco.com/mikuni-stacks-e ... ity-stack/