LCGB Forums

The ability to post messages is restricted to LCGB members. Any questions contact us at lcgbadmin@googlemail.com

Mikuni TM28 jetting advice please

Want to know which carb to choose? Having problems setting up the jetting details on your scooter? Wheter you are using a standard or tuned carb, ask your question here.

Mikuni TM28 jetting advice please

Postby Pompeydave » Sun Sep 09, 2018 9:09 pm

Hi all, I’ve got an Italian GP125 with GP200 gearing, a Casa 185 kit that has been bored out to 198, a BGM electronic ignition timed at 20 BTDC, a BGM big bore exhaust and a Mikuni TM28 carb. The carb is the new item. Can anyone suggest jetting, a needle and an atomiser please?
User avatar
Pompeydave
 
Posts: 137
Joined: Fri May 30, 2014 1:24 pm

Re: Mikuni TM28 jetting advice please

Postby Pompeydave » Sun Sep 09, 2018 9:11 pm

By the way the cylinder set up is with the squish set at 1.5mm and the piston sits at 1mm above the bottom of the exhaust port at BDC.
User avatar
Pompeydave
 
Posts: 137
Joined: Fri May 30, 2014 1:24 pm

Re: Mikuni TM28 jetting advice please

Postby Norrie Bodge » Mon Sep 10, 2018 10:45 am

Taken from here m8 but thinking as a starter point 4u -> http://www.smellofdeath.com/lloydy/carb ... %20exhaust


Lambretta 190 stage 5 Suzuki conversion with Mikuni 28mm & big bore exhaust

needle jet =169-08
main= 180
pilot=40
needle=2nd from top of clip or middle
Norrie Bodge
 
Posts: 529
Joined: Sat Aug 16, 2014 3:34 pm

Re: Mikuni TM28 jetting advice please

Postby bike grim » Mon Sep 10, 2018 11:35 am

I can’t assist with jetting advice but I would be cautious about your timing, at least whilst you are trying to set up. I’d be working on 18 or even 17 Deg BTDC to take account of modern fuel
User avatar
bike grim
 
Posts: 735
Joined: Tue Jun 03, 2014 2:51 pm

Re: Mikuni TM28 jetting advice please

Postby Pompeydave » Mon Sep 10, 2018 10:12 pm

Hi chaps, thanks for the replies- I'll try that setup first Norrie, cheers. Bike Grim, yeah know what you mean re timing- I only left it at that as my BGM stator slots need enlarging to get it to move round to -16/17, and I haven't got a decent Dremel attachment or grinding bit to do it at the moment.

Anyway, I'll try it with needle jet =169-08, main= 180, pilot=40, needle=2nd from top of clip or middle, and report back.
User avatar
Pompeydave
 
Posts: 137
Joined: Fri May 30, 2014 1:24 pm


Return to Carburettors

Who is online

Users browsing this forum: No registered users and 2 guests