Mikuni TM30 fitted to a RD350LC 4L0

[neilrowe]

Hi Chaps

I have a set of TM30 flatsides I am considering fitting to a 4L0. Has anyone got a baseline jetting for this? Would be helpful - much easier to start in the general ballpark, as most will appreciate.

Thanks

[rich]

Hi, nope sorry no such thing as a ballpark setting. The jetting will depend on so many factors - whether you are running airbox or filters, which pipes, state of tune, premix or oil pump etc etc!!

Need more info

[Norbo]

There is no starting point with carbs as every set are different and every bike is different . for example a pwk 28 may work with 130 main jet but a round slid VM mic carb would need a 240 and the mic flat sides being a more modern carb may be some were in between like a 200 or 210 . you just need to fit them take it for a ride not a thrash and see how it feels and adjust according

[neilrowe]

Thanks guys - reason I asked is that HVCycle advertise TM carbs on their USA website. They give details of the jettting they recommend for a std LC (yes, I know the 4L0 was not imported). They do not list a TM30 though.

Was hoping somebody had fitted these and could assist..

As Norbo says, the other way is to fit, start, ride and start buying jets:-)

FI:

Bike has been bored 2.25mm os
Squish: 1.2mm
Combustion chamber has been sized to yield a CR of 7.3:1
Exhaust port has been raised to 28mm
Running locally made spannies
Zeeltronic
I have "ported" the reed block as per Ed Ehrlenbach recommendations
Carbon fibre reeds
6mm reed spacer
Timing set at 1.85mm
Currently running std VM26 carbs (01 type). 27.5pj, clip 2 nothces from top, 240mj

bike has a flat spot at about 5500rpm which i am struggling to eliminate with jetting. Read somewhere that the flatsides flowed much better and helped with eliminating any mid range flatspots.

I have a couple of sets of VForce3 reedblocks on order too.

[smoke]

Hi,
Have a look at this link for the spanish TPR exhausts:

www.covacharasintin.com/shop/en/yamaha/47-227-tpr-exhaust-ypvs-rd-rz-350.html#/52-type_of_exhaust-shorts_for_footrests_without_passenger

But this is for the YPVS.

[neilrowe]

Some further updates for info:

1. I fitted a UFO flow optimizer to each VM26 (have not fitted the flatsides)
2. V Force 3 reed blocks installed with a 10mm spacer
3. Currently running 270 mj's

No more flat spots and the thing takes off like a rocket at 8000 rpm upwards (local spannnies and raised exhaust port have shifted the powerband upwards). Revs to 11000 in a flash once on the pipe. Bike is seriously quick now and a blast to ride.

Bottom line - perseverance.

As a side note: I purchased a set of pin gauges to accurately check my jets. It is amazing to see the variance in numbered jet sizes. A new Mikuni 240 is smaller than a well used one, for example.

Also two new jets with the same designated marking can vary considerably.