750S Brought back to Life

discussion about the 750 Sport and '89/'90 900SS, which share many mechanicals with the Paso series
q10115
Posts: 18
Joined: Mon Aug 26, 2019 4:29 pm
model: 750 Sport
year: 1990
Location: USA

Re: 750S Brought back to Life

Post by q10115 »

koko64 wrote:Great job and excellent update interpretation of the style. :thumbup:

I note that it has Mikuni TM carbs. Are they TM36 or 38's and are you happy with them? What jetting did you have to run with pod filters?
I am thinking about putting a kit together for 750 and 900 desmos as an alternative to the very expensive Keihin FCRs.

Hello! I am running TM36's with the following jets:

Starter Jet: #40 Vertical carb, #20 Horizontal carb. I found this arrangement to work best on cold starts for me.
Pilot Jet: #25 both carbs
Air Jet: #1.2 both carbs
Jet needle: #6FJ40 both carbs
Needle Jet: 389 series Q2
Main Jet: #210 both carbs
Needle Valve: #1.8 both carbs. This relieved the float bowl overflow, especially the horizontal carb.

Low profile pod filters, size 58-62 mm came from MikuniOz

I uploaded the PDF with the Sudco and Mikuni part numbers :)

https://drive.google.com/open?id=1U7d4_ ... N4t-CSXYxa
q10115
Posts: 18
Joined: Mon Aug 26, 2019 4:29 pm
model: 750 Sport
year: 1990
Location: USA

Re: 750S Brought back to Life

Post by q10115 »

I have also thought of putting on FCR39's but the TM-36 run fine and I'm enjoying the bike too much to dismantle everything just for the FCRs. I also was fighting to get the clutch piston and pressure plate to line up properly, and believed to have resolved the issue. Can't go without a little drama on this old thing :)
koko64
Posts: 91
Joined: Sun Feb 24, 2013 11:14 pm
model: other
year: 1999
Location: Melbourne Australia

Re: 750S Brought back to Life

Post by koko64 »

Thanks heaps for the base line data. Really appreciate it. Glad they run well.
2013 M1100Evo Street
1999 M750 "Scrambler"
2004 GSXR750 Track
q10115
Posts: 18
Joined: Mon Aug 26, 2019 4:29 pm
model: 750 Sport
year: 1990
Location: USA

Re: 750S Brought back to Life

Post by q10115 »

You're welcome! Hopefully they work out well for your case, too!
koko64
Posts: 91
Joined: Sun Feb 24, 2013 11:14 pm
model: other
year: 1999
Location: Melbourne Australia

Re: 750S Brought back to Life

Post by koko64 »

I got hold of two used slant bodied horizontal FCR39's with choke (enrichment) knobs designed for dirt bikes. Powerbarn provided a 2 into 1 throttle kit and Niche Cycle supplied manifold boots. After some fiddling they work well (on an M750 modified to dual sport). MikuniOz can sell everything to build a TM kit similar to your set up and I would recommend that as an easier cost effective kit for belt drives. Used FCRs can cost more than a complete kit for the TM 36/38. I'll do the TMs as a budget option if not requiring an accelerator pump. Thanks again for sharing.
2013 M1100Evo Street
1999 M750 "Scrambler"
2004 GSXR750 Track
q10115
Posts: 18
Joined: Mon Aug 26, 2019 4:29 pm
model: 750 Sport
year: 1990
Location: USA

Re: 750S Brought back to Life

Post by q10115 »

koko64 wrote:I got hold of two used slant bodied horizontal FCR39's with choke (enrichment) knobs designed for dirt bikes. Powerbarn provided a 2 into 1 throttle kit and Niche Cycle supplied manifold boots. After some fiddling they work well (on an M750 modified to dual sport). MikuniOz can sell everything to build a TM kit similar to your set up and I would recommend that as an easier cost effective kit for belt drives. Used FCRs can cost more than a complete kit for the TM 36/38. I'll do the TMs as a budget option if not requiring an accelerator pump. Thanks again for sharing.

Sounds good! I'm happy to have the TM's set up without much drama. I thought of the FCRs but the TMs work too well for me to dismantle and start from scratch again. I would also recommend getting a double pull throttle tube. Tommaselli's Daytona throttle assembly (http://www.mgcycle.com/index.php?main_p ... cts_id=739) works great and avoids the 2 into 1 junction. I had the 2 into 1 on my bike until it broke and I had to get the bike towed home. I bought the double pull throttle right after. I used 90-degree cable ends from the tube assembly down the handlebars and into the carbs. I custom made the cables and soldered the end knobs.

Happy riding, mate!
Last edited by q10115 on Fri Jun 12, 2020 5:30 pm, edited 1 time in total.
User avatar
Frank.61
Posts: 261
Joined: Fri Jul 24, 2015 11:21 am
model: 750 Paso
year: 1989
Location: Belgium

Re: 750S Brought back to Life

Post by Frank.61 »

Roger,

Perfectly executed, kind of restomod. :thumbup:
Love the black air cooled desmodue engines (with the alloy belt covers).
What did you do with the exhaust manifolds/pipes, is that paint or ceramic coating?

Have lots of fun with it! :beer:

Frank
Bimota SB4-S - 1984
Ducati Paso 750 - 1989
Suzuki SV1000S - 2008
Ducati Monster 796 abs - 2010
q10115
Posts: 18
Joined: Mon Aug 26, 2019 4:29 pm
model: 750 Sport
year: 1990
Location: USA

Re: 750S Brought back to Life

Post by q10115 »

Thanks, Frank! I inherited the bike pretty much how it looked :) I just brought the internals back to life and up to date. The header and pipes were painted, I think. My contributions were mainly the carburetor tuning, ignition coils, fuel filter, and chain/sprockets.

I also have a new shock on the way to bring up the rear end to quicken steering and reduce the shallow lean angle :D

Thank you!

-Roger
koko64
Posts: 91
Joined: Sun Feb 24, 2013 11:14 pm
model: other
year: 1999
Location: Melbourne Australia

Re: 750S Brought back to Life

Post by koko64 »

:thumbup:
2013 M1100Evo Street
1999 M750 "Scrambler"
2004 GSXR750 Track
q10115
Posts: 18
Joined: Mon Aug 26, 2019 4:29 pm
model: 750 Sport
year: 1990
Location: USA

Re: 750S Brought back to Life

Post by q10115 »

New shock installed. The bike now handles like a real motorcycle :D

Pictures here: https://photos.app.goo.gl/mjzezkNW6pnVsgRy6
Kmamac
Posts: 86
Joined: Thu Jul 21, 2016 6:56 pm
model: 906 Paso
year: 1990
Location: UK

Re: 750S Brought back to Life

Post by Kmamac »

The shock looks great. What type is it? Also what length did you go for? Is this standard. Inquiring minds need to know (well I need to know for future options on mine!
Yours selfishly
Keith MM in a super hot London
q10115
Posts: 18
Joined: Mon Aug 26, 2019 4:29 pm
model: 750 Sport
year: 1990
Location: USA

Re: 750S Brought back to Life

Post by q10115 »

Keith,

The shock is from Cogent Dynamics Engineering. It is 13.375 in (340 mm) long at the shortest and can be adjusted out quite a ways. The original carb SS shock was 13 in (330 mm), which had the bike steering quite slow in comparison. The SSie shock at 13.25 in (336 mm), offered a good length for many carb SS riders for quicker steering. Hopefully this helps!

-Roger
Kmamac
Posts: 86
Joined: Thu Jul 21, 2016 6:56 pm
model: 906 Paso
year: 1990
Location: UK

Re: 750S Brought back to Life

Post by Kmamac »

Thanks Roger, that’s very informative. Hopefully I will start getting my 750 sport sorted this year!
Best regards
Keith MM
q10115
Posts: 18
Joined: Mon Aug 26, 2019 4:29 pm
model: 750 Sport
year: 1990
Location: USA

Re: 750S Brought back to Life

Post by q10115 »

You're welcome, Keith! Happy to help and best of luck on getting your 750 running well :)
koko64
Posts: 91
Joined: Sun Feb 24, 2013 11:14 pm
model: other
year: 1999
Location: Melbourne Australia

Re: 750S Brought back to Life

Post by koko64 »

Put these on.

Image20200404_222145 by Tony Kokonis, on Flickr
2013 M1100Evo Street
1999 M750 "Scrambler"
2004 GSXR750 Track
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