Are you fitting your PWK's with the stock intakes? Or what intakes do you have on there now? Could you post a pic? Curious to see how you have it set up.
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Makuni VM34 Carbs = Backfire / Throttle Hang
- Thread starter MadMax1996
- Start date
Are you fitting your PWK's with the stock intakes? Or what intakes do you have on there now? Could you post a pic? Curious to see how you have it set up.
MadMax1996
XS650 Member
There is a rib inside the tube that slides into a rib on the carb. Cutting would miss align the rubber features on the inside. If that wasn't the case I'd be cutting some tube right about now. But you're saying any radiator tubing would work?
P.S. don't use the VM34's for aircraft!
I'm not familiar with those intakes...on mine, their just aluminum intakes with some thick hose (similar if not radiator hose) that slips over both the intake and the carb outlet. So the key is to get the carbs outlet to butt up against the intake as tight as possible, and then clamp down on the hose so the carb can't move. That way, the carb doesn't have any space between the intake, and therefore can't really flex up/down much. If there's a gap, the carb can/will flex especially with vibration. Since there's not an airbox to support it from the air inlet side, your relying on the intake to support the carb.
MadMax1996
XS650 Member
That's what has been causing my throttle to hang. Which is why I made a bracket that goes around the air filter clamp
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I've never seen anything like that before, Max. I've used aluminum mounts from both Shell Thuet and Michael Morse, and radiator hose was what they supplied. You could probably get the spigot to contact the mount if you trimmed the forward end of the sleeve.
That's an interesting mount Bosco, looks like the carbs are hanging more than being in a straight line from the intake (But could be the picture angle)... but that could be why you too are having your slides hang up as well. I don't know much about the PWK, but I like Keihin's PE carbs...I run them on my honda race bikes....they're solid. Same mount situation as the VM's though... need a tight fit against the intake so there's no flex/hang.
Thx brass. It must be camera angle because the carbs are pretty much in line with the head and spacer. The rubber adaptor is angled a bit to point the carbs out a bit on both sides.
Gentlemen not pretending I know anything or understand it
I don't use these carburetors
Please disregard if this is obviously impossible.
The problem seems to be to much movement of the carb
On the picture the frame tube is visible .I wonder if not a Pipe clamp can be put there.
With a hanger downwards .. Or to the sides.
As a " Brainstorming " suggestion a clamp and
? hose clamp around the carburetor.
? Flatbar under ?
? Angle bar under ?
would restrict the moving around.
MadMax1996
XS650 Member
You could use either of these. I simply typed in hose clamp bracket in Google and found these. The second one is closest to what I'm using. Mine is just a half inch wide piece of thin gauge steel that I milled out slots on both ends to slide a hose clamp through. I then wrapped it around the frame under the seat to hold the hose clamp around the air filter to the frame to prevent bending of the intake hose.
Great idea. I’ll have to look into this tomorrow.
