Won’t rev past 7000 rpm

[Buffalo Bill]

Maybe the valve springs are worn out, so the valves are floating already at 7000?

[Nessism]

The compression is fine. And valve springs don't cause problems like this. New carb diaphragms throws a red flag. Where did you get them, and how did you go about the process of changing them. Mind you, changing diaphragms is doable, but it's not an easy task.

[gustovh]

Just a thought that ou may have 1 pin too many between the cam chain. Ie 21 instead of 20 pins between cam marks. This would delay intake and limit rpm. Worth a check, yes happened to me and 7000 seemed to pretty much be the limit until I corrected the issue, ran flawless after that.

V

[xxenzor]

Nessism I got the diaphragms from JBM, and I also have spares from eBay. The bike was having the same issue before I replaced them. The old diaphragms were in good shape with no holes, but I must have pinched one during reassembly because the left diaphragm blew up as soon as I started the bike.

[Nessism]

Put your finger inside the carb throat and lift the slide up to the top of its travel, then let go. The slide should move up smoothly, then when you release, it should move down with a damped motion, and clunk as it reaches the bottom.

[xxenzor]

Nessism Yes they both go up and come down smooth. Same as if i blow air in the port they go up smooth and come down all the way good

[xxenzor]

Anyone got any ideas?

[tom203]

I’d replace the condensers..in case they’re breaking down

[gustovh]

Check your cam chain links.

[dgates1]

With how far you need the pilot screws out to run best.. I'd check your petcock and vacuum hose. May be losing vacuum and not supplying enough fuel.

Does it run fine with a remote tank and no petcock (with vacuum line plugged)?