78 GS750 Yoshimura Resto-mod

[Guest]

She's alive! Got the wiring and carbs in over the weekend, fired up pretty easily. Still need to sort out the proper jetting over the next week or so and doing some other minor adjustments before getting it saftied.

pics https://photos.app.goo.gl/NfSGu31iBPSgFAXz2

 

[thebrandonbeezy]

Have you measured your rake and trail?

 

[steve murdoch]

Congrats, Matt.
That rear brake line looks a bit loooong?

 

[Guest]

Have you measured your rake and trail?

I haven't yet. suspension and brakes will be the next thing I tackle! I plan on swapping out the swingarm for the 1100 aluminum box swingarm and probably a bandit 1200 front end.

 

[Guest]

Congrats, Matt.
That rear brake line looks a bit loooong?

Thanks! And yeah it is, unfortunately ordered one that was too big, I'll have to swap it out with a shorter one in the future

 

[Guest]

Just got back from my first break in ride after fixing the shifting issue. The engine pulls like nothing I've ever experienced, still need to mess with the jetting in the mid and low range but my main jet selection feels about perfect (107.5).

 

[one_civic]

your really restricting your bikes potential with the stock vm26's and airbox, if you need some help, send me a PM

 

[Guest]

Just the stock VM26 that came with the 750. Although I know this Yoshi Topend previously had Mikuni RS carbs on it.

Shims. Intake: 2.80, 2.75, 2.75, 2.75
Exhaust: 2.70, 2.65, 2.70, 2.80

 

[one_civic]

your gonna need bigger carbs, you can use the 34mm CV intake manifold rubbers from any of the 8v gs bikes, you could then use Canadian 85-87 gsxr750 Mikuni Vm29ss flat slides, re-space the throttle linkage shaft to have both outer carbs moved in 1mm for exact spacing. And convert it to centre pull instead of the stock left side pull.
All these parts are available as well as the o-rings,

http://www.cycleorings.com/

 

[Guest]

your gonna need bigger carbs, you can use the 34mm CV intake manifold rubbers from any of the 8v gs bikes, you could then use Canadian 85-87 gsxr750 Mikuni Vm29ss flat slides, also you can machine and re-space the throttle linkage shaft to have it moved over to use your stock push /pull throttle cable and not have it hit your tank, get some K/N's too,

All these parts are available as well as the o-rings,

http://www.cycleorings.com/

Thanks for the advice! I'm definitely looking to do something along these lines in the future, I imagine that this stage lack of airflow is the limiting factor to making more power. Especially with the ported head and Yoshi Cams.

The hard part is finding these carbs for sale. A friend of mine has some VM28's for sale, would those suffice?

 

[one_civic]

I got 2 complete pairs when I made my setup,

1 was a trade for a 24 of Canadian,
2nd set for $80
machine work cost $200,
0-rings, bowl gaskets, $100
case of 80 jets, $50

 

[one_civic]

28's would be better than the stock 26's, just make sure their not off a kz, air jets are fixed and a couple of other minor things as well

 

[one_civic]

your gonna wanna also upgrade your stock ignition to a dyna electronic and coils

 

[Guest]

I'll have to keep an eye out for them then! Machine work isn't an issue, I can do that all at work.

What was your setup?

 

[one_civic]

Send me a pm

 

[Guest]

A friend of mine has an entire bandit 1200 front end and rear end for sale including rims, brakes, everything. I've heard alot of these parts can be made to work on the 750 is this true?

 

[hillsy]

A friend of mine has an entire bandit 1200 front end and rear end for sale including rims, brakes, everything. I've heard alot of these parts can be made to work on the 750 is this true?

The front end is relatively easy as it is more or less just a bearing swap. The rear is more involved as the Bandit rear rim will be too wide for the GS swingarm. If you got the Bandit swingarm, you could use that but you'd need to weld on shock mounts and machine / spacer the pivot. Then adjust the chain line.

All do-able but depends on what you can do / how much you want to modify / spend.

 

[Fjbj40]

Front end is not a bearing swap, that is if the 750 stem is the same as the 1000 stem. The Bandit stem will not work on the 1000 that I can tell you.

I had to press out the Bandit stem, build up the 1000 stem with weld then machine it down and press into the Bandit lower.

However, it is way worth it with the modern wheels, brakes and suspension.

For the rear you need the GS1100 swingarm, modify the rear sprocket mount, narrow it some. Do a 530 chain conversion with an offset front sprocket. You will need to have some of the spacers modified or new ones manufactured.

good luck

 

[Guest]

Thanks everyone for the input! I probably won't be tackling this swap for a while, but I have a spare frame I can mock up both the front and rear end too which will be convenient. The machine work shouldn't be a problem,I have access to all the necessary tools. I'll post pictures when I pick the pieces up

 

[hillsy]

Front end is not a bearing swap, that is if the 750 stem is the same as the 1000 stem. The Bandit stem will not work on the 1000 that I can tell you.

I had to press out the Bandit stem, build up the 1000 stem with weld then machine it down and press into the Bandit lower.

However, it is way worth it with the modern wheels, brakes and suspension.

For the rear you need the GS1100 swingarm, modify the rear sprocket mount, narrow it some. Do a 530 chain conversion with an offset front sprocket. You will need to have some of the spacers modified or new ones manufactured.

good luck

OK - the front end is not so much a bearing swap as finding the right bearing to use. All Balls Racing has a conversion calculator, but the GS has a 48mm OD bottom bearing whilst the Bandit bottom bearing is 55mm. So, you need a 30 x 48 bearing to use the Bandit stem in the GS neck for the bottom. With the top you can use the GS bearing as it has the same ID as the Bandit (25mm).