Mikuni carb
- Thread starter FastFred
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Is this a new Mikuni? If so, the slide is unlikely to be sticking, however remove the carb, and take off the cap and spring(s). Gently push the slide up and down in the body. It should rise and fall smoothly. If yours does that, the "sticking" is most likely to be in the cable or twistgrip. There should be no need to have a 2nd spring in a Mikuni.
Mick
Mick
Fred,
I made the same double-spring mistake with my Mikuni last year; turned out to be a slighty bent cable. As Mick said, the original spring is more than adequate to snap the throttle back when released. When you are about to remove the extra spring and test the slide, remove the fuel tank as well. Test the slide, then replace the original spring and test the throttle response with the cable unconstrained. If the response is still mushy, the problem is in the cable or throttle. If the response is crisp, the cable had been bent under the tank. Carefully replace the tank while continuing to test the throttle to insure a smooth cable path; it doesn't take much of a bend to affect the throttle feel. There is enough room above my Mikuni to bring the cable in vertically, and to avoid an angled entry.
I made the same double-spring mistake with my Mikuni last year; turned out to be a slighty bent cable. As Mick said, the original spring is more than adequate to snap the throttle back when released. When you are about to remove the extra spring and test the slide, remove the fuel tank as well. Test the slide, then replace the original spring and test the throttle response with the cable unconstrained. If the response is still mushy, the problem is in the cable or throttle. If the response is crisp, the cable had been bent under the tank. Carefully replace the tank while continuing to test the throttle to insure a smooth cable path; it doesn't take much of a bend to affect the throttle feel. There is enough room above my Mikuni to bring the cable in vertically, and to avoid an angled entry.
FastFred said:
I put a 34mm Mikuni on my 72 750 and I didn't need to bend the cable 90 degrees. It has a MAP manifold.
I did put an Amal spring inside the Mikuni's however as the throttle stuck open once while at full throttle. Only went down after I used kill switch to slow her down
http://i924.photobucket.com/albums/ad82 ... CF8671.jpg
splatt said:
The only time mine will stick, or seems to, is when it is wet or damp. The first time it happened was in August going on holiday in the pouring rain, I had only gone 3/4 miles when I noticed there seemed to be a reluctance for the revs to drop when I shut the throttle. Rather than take the chance, as I was going to be riding on single track roads, I turned back and changed bikes. Has anybody an idea why it does it in the wet and damp?
Is it strange that Mikunis work perfectly well on millions and millions of Japanese and other bikes yet when used on Nortons all kind of skullduggery arises to thwart their performance and to force one to consider switching back to the Amals? Is it like a human transplant recipient's body rejecting a newer, much healthier organ because it does not come from a related compatible source? :twisted:
dorteerts said:
agree!
Personally, I am a huge fan of properly set up Mikunis. I've never had a problem with the slides or springs in any of them - ever.
I have a couple of sets of Amals in a box under my workbench. I'm pretty sure I won't put them back on any of my bikes.
(not one that I would want to ride regularly anyways).
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