TM34-B65 carb setup on Skorpion (updated with Ignitech CDI)

[Anders]

Sorry for the double post, thought it might be better to post in the 660 section as the Mechanic/Tech talk section seems to get very little activity, my mistake.

I recently came across a set of Mikuni TM34-B65 flatslides that previously graced a SZR based Supermono race bike, The SZR was not bored out but had a ported head, comp piston and a hot cam so the jetting should be fairly close to my needs since I have roughly the same setup on my -95 Skorpion.

Anyway I know the carbs will fit the intake on the Skorp but are there any other issues, apparently it hooked up directly to the SZR throttle cable set-up but are there any diffrence in this regard between a SZR and Skorpion? Do I need to modify or fab something up in order to make this work?

I'm not clear in how I will solve the intake side yet, currently I am running the airbox with no top cover using a K&N style modified filter. The Mikunis are set up fo K&N pod filters wich also came with the carbs. It looks like I can use the stock airbox if I want to, any thought are appreciated.

[Anders]

Havent got around to fit the carbs yet, too much to do at work before the summer vacation starts...

Anyway, is there anyone that has done this mod on the forum that can share some of their experience with me

[Anders]

Update,

I finished fitting the carbs on the bike this afternoon, it took me about 2 hours to cut, fabricate, weld and mount the carbs with a modified fixture for the cables to clear the underside of the tank. There was just enough space to squeeze in the K&N pod filters after removing the intake rubbers connecting to the airbox. More or less plug and play.

Unfortunately the bike developed some electrical issues yesterday so I havent been able to testride the new setup... Did run fine on saturday, non starter on sunday even with start gas... weak spark so I'll have to check the electrics. Battery is fine, a 14Ah gel battery wich gives me 6-7 good tries before it starts to fade.

[Anders]

I decided to add a Sparker unit from Ignitech to make the most of the new carbs, as Bill pointed out the advance of the stock CDI is al little bit too much. Also I am suspecting my modified (removed rev limiter) stock CDI may be the cause of my troubles getting the bike to start.

So I'm hoping to improve a bit on the previous dyno results (using dialled stock carbs, ported/flowed head, big bore comp piston and "hot" cam) but most significantly throttle response should be much better.

Current set up.

Skorp_dyno.jpg (30.71 KiB) Viewed 10005 times

Garage1.jpg (239.96 KiB) Viewed 9941 times

[Anders]

Som pictures of the end result

MT34_B65_1.jpg (226.23 KiB) Viewed 9956 times

MT34_B65_2.jpg (189.85 KiB) Viewed 9956 times

MT34_B65_3.jpg (206.4 KiB) Viewed 9956 times

[Anders]

IgniTech Sparker TCIP4 unit hooked up and programmed...

Sparker.jpg (262.15 KiB) Viewed 9858 times

Haven't started the bike up yet, battey was flat... may need to replace it as well.

[alfredoenrique]

Will this set up work on a 2005 baghira? Do I have to change CDI retune etc, or just bot on a tinker a bit?

[Anders]

The TM34-B65 carb combo fits all MuZ/Yamaha 660 5-valve engine twin intake rubbers. You may need to adapt the connection rubbers to the airbox or replace with K&N style pod filters. Also there may be a need to adapt the cable stay to fit under the tank (which I had to, thanks Bill for the heads-up on that) but there may be more room on the Baghira.

There is no need to change the CDI unless you want to remove or alter the rev limiter.

Jetting of the carbs is necessary to suit your setup unless you can get a pair that is allready set up for your bike, then of cource its just a matter of tinkering to get it all working perfectly.

[fraserc]

Anders,
That looks like a pretty good setup. But how does the Skorpion run; pleased with the result?
Cheers,
Fraser.

[Anders]

Compared wit the stock carbs there is definately much better throttle response, its a world of diffrence actually even considering that I had my stock carbs as dialled in as is humanly possible..

The carb swap alone on a stock engine should give you a 4-6 bhp boost plus the added bonus of crispy throttle response if that is what you like, little less driveable in town but its worth it to me.

I have not been able to get a proper feel about the Ignitech box and what it can do since I am experiencing some strange electrical problem that I'm trying to sort out, the bike runs well when it starts but 4 out of 5 tries it will not fire at all, not related to the CDI though. Checked ignition coil, pick-up, Battery, all connectors and grounding points in the harness but I have yet to find the culprit....

[Bill Jurgenson]

chekc the arcives for this topic, there is lots there, here just two excerpts:

http://www.mzriders.com/viewtopic.php?f=3&t=2172&p=12620&hilit=flatslides#p12620
http://www.mzriders.com/viewtopic.php?f=3&t=1972&p=11640&hilit=flatslides#p11640

TM34 get you ±5 hp more on the stock engine with no other mods and that with much better mileage. I personally think drivability is much better, too, but you do have to learn how to use your right hand correctly, something you'llnever ever learn with CV carbs.

[djsbriscoe]

What jets are needed for the standard engine setup with this carb? Also is the carb any easier to remove/replace than the OEM one.
I would like to fit one but so far I've only seen ones described as not street legal.

http://www.kedo.com/products/30230/1/1.html

Can anyone point me to a possible source for a used one.

Thanks.

David.

[hb7]

Check the harness around the steering column....the front diode is located there.
I had a broken wire up there which would make the bike die.

How much better gas mileage with the CV carbs....?
Stock is good for ~40 mpg with spirited right hand.

[Anders]

Havent tried the TM34-B65 setup on any stock 660 engine, however I do have a second unit set up for a stock XT600.

Mikuni TM34-B65 base set up for XT/SRX600, the 660 may need to go a little bigger on the main jet but its a god starting point.

Main jet: #105
Secondary: #20
Needle: Middle position
Mixture 1-1.5 turns out

If you are using K&N type pod filters they are perhaps a little bit easier to remove/replace than the stock units, not much though. I use a little bit of grease to facilitate easy removal/assembly.

They are described as not street legal in the Kedo site because they are not TuF approved, hence not street legal in Germany. If they are street legal or not where you are located depends on what modification you can do to a vehicle and still pass inspection...

[Mike G]

With this set up do you have both carburetors openning together or staggered like the stock set up? Also as one carburetor feeds 2 intake valves an the other feeds only 1 are they both jetted the same?

Mike