Author Topic: 3MA Track Bike Project, JL exhaust, TM 32 no airbox  (Read 942 times)

kischde

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3MA Track Bike Project, JL exhaust, TM 32 no airbox
« on: February 08, 2018, 11:34:31 PM »
Hello,
is there anybody out there who is using a 3MA with JL exhaust, TM32 carbs without airbox?
I want to build up a second 3MA, just for track usage.

I have already a complete stock 3MA3, so finally is my question is: Does somebody knows a basic setup of the carbs?
I need something to start, read somewhere starting with 400 jets should be okay. This sounds a little high?
I want to use the "simple" TM32 (baught direct from Mikuni), not the stock one.

Any hints are very welcome!

All the best from switzerland
Kischde
« Last Edit: February 08, 2018, 11:42:03 PM by kischde »
TZR-3MA3 1990
RD-350 YPVS 1WT 1988
TZ-500J 1982
TZR-3MA track bike in progress

vinny

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Re: 3MA Track Bike Project, JL exhaust, TM 32 no airbox
« Reply #1 on: February 09, 2018, 05:54:58 PM »
Hi
I tried to fit a pair of  keihins of Honda cr 125 but  to be honest I  never got it to run that well as bike had a few other issues.
The carbs  were probably a bit on the big side to be fair  .
Plus second hand carbs can be a bit hit and miss.
On the plus side They were much easier to work on than the std carbs which was good .
I would like to build another 3ma in future and will probably go the same route you are .
Sorry can't be of any more  help.
Good luck I will be reading with interest ☺.

Warwick

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Re: 3MA Track Bike Project, JL exhaust, TM 32 no airbox
« Reply #2 on: February 10, 2018, 11:36:17 AM »
It would probably make the most sense to start by experimenting with and setting the pilot jets/air screws, needles and needle jets so that you have it running cleanly off the stop and to 1/2- 3/4 throttle (but not high revs at this stage) using whatever main jet the carbs ship with unless it's very small.

Then fit main jets that are of a size that do not let the motor rev out when you try it at WOT and then gradually and very carefully work down on the mains a size at a time until it revs cleanly and the plugs are an ideal colour after an extended WOT plug chop. Make sure that you check the plug colours on both cylinders when chopping as you may need to run slightly different sized mains in each carb to find the ideal WOT setting.

Good luck. And proceed with caution, obviously...  :o  (-P)
« Last Edit: February 10, 2018, 11:38:16 AM by Warwick »
Still Smoking...

kischde

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Re: 3MA Track Bike Project, JL exhaust, TM 32 no airbox
« Reply #3 on: February 10, 2018, 12:03:34 PM »
I saw today in the 3MA Sugo Manual the jets for SP and FIII Kit. In the FIII coloumn the main jets are from 360-420.
So I will start with the 400 
Was FIII also runinng without airbox? I think so, but I am not 100%

First setting the bike I will do on bench, so this makes live easier.
However it will take a couple of weeks to start with it, as I have to collect a few more parts to get the bike into running condition...
TZR-3MA3 1990
RD-350 YPVS 1WT 1988
TZ-500J 1982
TZR-3MA track bike in progress

casal-fan

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Re: 3MA Track Bike Project, JL exhaust, TM 32 no airbox
« Reply #4 on: February 10, 2018, 12:31:19 PM »
Grüezi Kischde

3MAs are a bit complicated.
I have been running mine for 3 years now, everytime I make it a bit better on one side, it gets worst on the other... so there is not much I can say to help you.
The sugo thing is also quite blury in my opinion...
I can maybe help you with one thing.
Found this pic on the interweb, a site for 2 strokes. I have had many plugs coming out like the first in the left, and thought it was spot on... just to kill the engine afterwards, so the pic. bellow might be a good reference when jetting...
Good luck !

kischde

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Re: 3MA Track Bike Project, JL exhaust, TM 32 no airbox
« Reply #5 on: February 10, 2018, 12:54:25 PM »
Thx a lot for your hint.
With jetting we (my father and me) are quite experienced (Don´t get me wrong, I do not want to be any kind of arrogant)
We are using the upper one since the 80´s
And this bike is horror to jet without experience, because of the outer reversed cyilnders.

Any hint is welcome, to get a base setting to start with!
TZR-3MA3 1990
RD-350 YPVS 1WT 1988
TZ-500J 1982
TZR-3MA track bike in progress

Fabien F

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Re: 3MA Track Bike Project, JL exhaust, TM 32 no airbox
« Reply #6 on: August 18, 2019, 11:40:05 PM »
Hi

Do you have good feedback on the lomas pipes?
89 3MA
95 Cagiva mito
95 Cagiva mito SP
1963 Vespa 150
87 Yamaha Zinger

kischde

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Re: 3MA Track Bike Project, JL exhaust, TM 32 no airbox
« Reply #7 on: August 19, 2019, 12:05:54 AM »
At the moment they just look very good, as I have another issue, with my “low mileage, very good condition“ engine....

http://pure2strokespirit.net/forums/index.php?topic=6119.msg61998#msg61998
« Last Edit: August 19, 2019, 12:08:07 AM by kischde »
TZR-3MA3 1990
RD-350 YPVS 1WT 1988
TZ-500J 1982
TZR-3MA track bike in progress

Edd

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Re: 3MA Track Bike Project, JL exhaust, TM 32 no airbox
« Reply #8 on: September 13, 2019, 02:16:17 PM »
Hi
 
If running std 32mm carbs of a 3ma1. Remove vaj set up insert a fixed air jet size 100 on carbs jet it 240 mains (1200m amsl) to start with; plug chop from here onwards; with std pilot. Make sure of the float levels; this is crucial on a 3ma in my experience.

Edd
TZR 250 3MA1
TZR 250 3XV RS(Track)
TZR 250 1KT
TZ 250 3YL
RZ 350 Hybrid
YZ 250
RD 350 Hybrid

kischde

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Re: 3MA Track Bike Project, JL exhaust, TM 32 no airbox
« Reply #9 on: September 13, 2019, 10:56:58 PM »
Meanwhile I´ve bought a set of TM 34 with powerjets (the Mikuni standard, nothing TZR related).
I´m building up the top end at the moment, the zeel is fitted (thx to your recomondation) and a few bits are missing, before I can do the first fire-up..
TZR-3MA3 1990
RD-350 YPVS 1WT 1988
TZ-500J 1982
TZR-3MA track bike in progress