Mikuni Set Up Problem

[vibration]

Got a set of 32mm for my CB500T project but I can't seem to get them right...wet plugs and unburned fuel out the tail pipes. I saw where others here had used the same carbs and got good results with mains at 185, pilot 30, needle 6dh7 with clip on the top. We've gone all the way down to 143 and the plugs are still wet. Any ideas?

 

[HerrDeacon]

When are the plugs getting wet, only when testing WOT? Do you have the pilot, mixture screw and idle dialed in yet. Is this a VM carb, if so I found their online tuning guide a very good starting point, just take it one step at a time and only make one change at a time. http://www.mikuni.com/pdf/vmmanual.pdf

 

[Big R]

For what it's worth, Dreadrock has VM32's on his XS500 as well. Might want to send him a pm for details about how his carbs are set up......

 

[DreadRock]

Right now I have the set up on my VMs :
Main 120
Pilot 30
Clip 4th down from top
Air screw 3/4 turn out

Seems to be running strong now from top to bottom ! Think I have a simple worksheet on my computer that maritime gave me . It might be on the last couple of pages on my build thread also If not ill send it to you ...

 

[Big R]

Vibration : I'm just curious, but where did you find somebody running 185 mains in a 500 twin that were running good? Because I have 185 mains in my 650 twin.

And depending on some other factors, wet plugs on a running bike usually aren't good. Wet with gas = not getting complete combustion (usually weak spark). Wet with oil = not good at all.

 

[Kanticoy]

Re: Re: Mikuni Set Up Problem

Vibration : I'm just curious, but where did you find somebody running 185 mains in a 500 twin that were running good? Because I have 185 mains in my 650 twin.

No doubt. My 750cc BMW only runs 190s.

Sent from my DROID RAZR using Tapatalk 4

 

[vibration]

Vibration : I'm just curious, but where did you find somebody running 185 mains in a 500 twin that were running good? Because I have 185 mains in my 650 twin.

And depending on some other factors, wet plugs on a running bike usually aren't good. Wet with gas = not getting complete combustion (usually weak spark). Wet with oil = not good at all.

I saw that the 500T Bobber that Moho had vm32s and those are the numbers he referenced.

 

[vibration]

Scott,
Found the chart in your build thread. Thanks!

 

[DreadRock]

Good to hear its a great starting point ! Take your time and work thru it !