Hi I recently fitted a VM36 carb I have one problem, when the bike has been left to stand overnight or for a few hours starting is fine but irrespective of how long I leave the choke on for when I take the choke off the engine runs like it is suffering from slight fuel starvation for about a mile, have currently got a 35 pilot jet but have had same problem with the next 2 sizes up. With the 35 the idle after this initial period is rock solid at 800 rpm and no other problems.Any ideas..?
Mikuni VM36 Advice
- Thread starter plj850
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splatt said:
Hi I have tried it with running with the choke on for anything from say 30 seconds to 3 to 4 minutes then choke off, same thing happens.( I am used to the Amal Carbs and basically I never had a choke just the right amount of tickle fire her up and away
never really needed any warm up time then just would take a couple of minutes before the idle settled then no probs.
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I recently went from a 40 pilot to a 45 on my VM36. With the 40, my pilot air screw was all the way in. With the 45 I am about 2.5 turns out on the air screw. I generally start from cold with the enrichener circuit on and then turn it off after about 20-30 seconds. There are cable attachments available which allow you to control the enrichener circuit from the handlebars like the Amal air levers. These should allow you to control the enrichener circuit in finer increments but I have neever fitted one so don't really know. It sounds to me like your pilot circuits may need a cleaning.
tpeever said:
Hi thanks for the advice cleaned the carb obessively
then I tried switching the enricher circuit off after like 10-15 seconds and seems better no faltering I guess I only need the enricher circuit on for starting and then just knock it off. I think I have been leaving it on for too long...new fangled carb...tpeever said:
No the choke circuit is still a switch,on /off, you can get a little bit of control just before it closes,but
they are much nicer to use than that ugly hiden leaver.I only use the choke to start,close straight away and hold the revs manually until it will idle,if I let it warm up on the choke it misses und blubbers down the road for a mile or two.I don't commute on my bike every day , if I did I think it would becme very annoying.
splatt said:tpeever said:
No the choke circuit is still a switch,on /off, you can get a little bit of control just before it closes,but
I only use the choke to start,close straight away and hold the revs manually until it will idle,if I let it warm up on the choke it misses und blubbers down the road for a mile or two.I don't commute on my bike every day , if I did I think it would becme very annoying.
Hi thanks matches my problem exactly so I am now turning the choke off straight away.I wonder why maybe a Mikuni carb guru has the answer. :idea:
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I have a similar type of enrichener circuit on the Mikuni TSM carbs on my 96 Thunderbird and the the handlebar lever allows a lot more control than the "on-off" lever on the front of the carb. Not sure it's really needed though. On my Commando, I start with the circuit fully on and switch it off after about 20 seconds. Then I raise the idle screw to keep it running until it warms up. Works fine. I think if your bike is not running well after a few minutes warm-up, you need to look more carefully at what is going on. My Mikuni has been flawless since I installed it 3 years ago. Huge improvement over the Amals!!
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