Triumphrat

valiantbultaco · 11-16-2009, 04:33 PM

Hi enthusiasts,

Firstly, sorry to offend the purist by talking about mikuni's!!

Secondly can anyone tell me the best jetting sizes etc for running mikunis on a 71 T120R in average conditions.

Some say i have flooding carbies and fuel getting blown out of one exhuast etc etc or weak spark.

I just need some clarification that i am set up how i should be!

Thanks again in advance!!!

GrandPaulZ · 11-16-2009, 04:49 PM

WHICH specific model Mikunis?

valiantbultaco · 11-17-2009, 06:37 AM

twin 30mm vm brand new

pookybear · 11-17-2009, 09:21 PM

Quote:

Originally Posted by valiantbultaco

twin 30mm vm brand new

http://www.jba.bc.ca/Bushmans%20Carb...g.html#SYNCHRO

A nice read here, but based on the VM 32 unit. However, Mikuni
needles have more than enough adjustment in them (5 notches in-
stead of 3) you should have no problems with useing these number
in a 30 unit. Just stay on the lower end.

And a personal note, I found the main jet numbers that are given
to be way to big. I had to go much smaller. But this is something
you have to work on a little at a time. Better to be rich and lean.

Pookybear

valiantbultaco · 11-19-2009, 12:09 AM

I inspected the right carby today and have found the issue.
Behind my right hand carby air filter, I had forgotten to remove a rag which i had placed there during the rebuild to keep dirt/bugs out etc!!!

I had completely forgotton about it untill i removed the carby for inspection today. The rag had been sucked into the carby under the slide and jamming it fully open, thus flooding the engine with fuel and not sparking luckily!!!! Lucky the rag didnt get sucked into the engine completely!!

I'm yet to get it back together and retest but i'm assuming that was the issue hehehehe.

Hrrrmmmm,......thats a good one! I'll remember that next time!!!

VB

sangalfie · 07-08-2011, 03:40 PM

in regards to the mixture screw on the Mikuni VW 30 series...

How do I make it rich / lean? Screw in/out?

Russell P · 07-09-2011, 10:05 PM

sangalfie,

Screw in: enriches the mixture(less air, more fuel)
Screw out: leans the mixture(more air, less fuel)
If you get a chance: go to 6x6world, look for their mikuni tuning articles there. Will tell you more than you ever wanted to know about mikunis.

ARTY · 07-11-2011, 09:36 AM

Hi valiantbultaco

Size 30mm Mikuni Carbs - for a T120R :
PILOT JET : 20
SLIDE :3.0
NEEDLE JET TYPE :159
NEEDLE JET SIZE P-2 , P-4
NEEDLE :6DH2
MAIN JET : 180
AIR JET : 1.0

ALL NEEDLES BEGIN IN THE CENTRE OR 3RD CLIP NOTCH

Let us know how you get on .