A Water buffalo saved.. Its a disease

[rd400greenhorn]

So, not Really a finished bike nor a 'show off'
Just thought i had to share my latest.. Purchase

It was sitting in a barn with a Load of suzuki gt parts, 380, 550 and this 750 frame.
A somewhat complete engine, a set of rims (wont be using these) and a clean frame.
Basically what i would need for a cool project in the years to Come and AFTER the rd400 is done  and without me having to tear in to a expensive original gt750.

Oh well, Another 2 stroke is taking up space in the basement. I need to move into a house with a garage before this build can begin, but a 750 2 stroke... I had to have it 😅

[rd400greenhorn]

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[rd400greenhorn]

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[busa1300]

At least someone pulled the cylinders off for you already.....that can be an agonizing job in most cases.
I loved my 72 GT750 that I had, but I needed to sell it to have extra $$$ for my RZV500 project.

I have a basket case GT that has been waiting for attention for about 5 years now.
A large number of possibilities with these bikes for upgrading suspension and engines today.
I just bought another two stroke from Japan, so this one has to go now too.

[Czakky]

How do the GT750s react to pipes and porting? I know they were midrange lazy tourers from the factory, but can they become gnarly fire breathers?

[tony27]

In theory they should respond well due to being 1 1/2 T500s with watercooling, both were tuned more for a wide powerspread rather than peak power
I had a friend build 1 up for post classic racing using a ex speedway sidecar motor, when the pipes were being designed with 1 of the programs they found they needed to add transfer to give a better powerspread. I do remember the pipes that were built were run the same as the TR750 with 1 curling around behind the block
From memory the 500s & 750s don't tolerate spending their life in the redline, the skirts are known to crack as the left 1 appears to have done if over revved to often
Should be an interesting project

[Cobraace2]

This one runs strong

[busa1300]

Real strong with the nitrous 

[rd400greenhorn]

That buffalo looks mighty powerfull

[m in sc]

guy i know named lane (rngdng on the kawi board) has one, he milled a few mil off the cyl and used a jackplate to raise the cyls, then he cleaned up the porting to take it to TR specs. ( i know this because I'm the one that milled the cylinder for him) its pretty gnarly for a street ridden GT750 old school build. it will, no lie, power wheelie at 30 degrees all the way through 1st gear . jemco pipes, and 34mm carbs dialed in with a boyer ign. Not the most powerful one out there by a long shot, but i rode it years ago, he still has it. Me? i have zero interest in them but they are capable. just too porky for my tastes. His bikes been described as an 'h2 with manners', which is actually fairly accurate with the power delivery.

[busa1300]

Yea, the engine is crazy heavy for what it is....definitely bullet proof though.
Here is a place for some serious GT750 TR750 parts.
https://bdkraceeng.co.uk/tc/search.php?keywords=tr750&x=0&y=0&sid=8p3hdn7pddinadpfehjdkl8252

[rd400greenhorn]

Wow
Thats some crazy parts for the old gt750.. Damn

[teazer]

And not insignificant prices either.

I have two race blocks here.  One by Doug Flannery that did the Hatchet nitrous 9 second bike and the other by Richard Fortino that built the fastest normally aspirated GT750 back in the day.  Two different approaches to overcoming the casting short comings and both should make more power than a TR750.

Mine in its first incarnation with a very mild street tune and Jemco pipes with stock BS40 CV carbs made 76rear wheel HP IIRC.  I just finished porting one with similar spec to Lane P's and it should make 100 rwhp. Stock they make less than 50 at the rear wheel.

They are as heavy a/f but mine is about 100 pounds less than stock.

Like most bikes from that era the castings are a bit rough and aluminum to steel liner tends to have a step.  Matching all the ports usually ends up with longer duration for the street than planned, but they are still streetable.  It just take a lot of time and the right tools to get it done.

The recipe is 4.0mm off the top of the block to go with a 3mm lift plate and additional base gasket, then raise the exhaust  port and lower the exhaust transfer and inlet port floors. Shorten the inlet divider and match the inlet to the 40mm stock CV carbs, Go up on the mains, add Jemco pipes and a decent exhaust and electronic ignition and Robert's you mother's brother.

Always use a correct size Cometic head gasket and if funds allow, a squish head.

Caution: Don't try to raise the exhaust port too much or straighten up the top edge.  You will break through into the water jacket.  Same on the outer transfer ports.

[rd400greenhorn]

True, its very expensive.
But When time comes i Would love to have around 100hp, and the plan is to Sheed as much weight as possible, for the acational summer blast ride on the street.

Sounds like you have a lot of knowledge on the gt750, i Will definately take note to your info, much appreciated