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Discussion Starter · #1 ·
I have been a member for years and posted in the NOOB section about a RMZ250 I was going to try to street legal and customize. As things go that bike was sold, some job changes, location changes, and a extra child mad that all go away.

Things have finally settled down and I picked up a 1974 RD350 that I rebuild and then sold, a 1980 GS450 I am rebuilding, and this 1973 Suzuki GT750, a bike I have wanted for a long, long, long time.

I got it for $500 dollars with the tank and seat already done like you see in the pics, only 2 of the 3 needed expansion chambers, and about 25% of the parts needed to make the bike run missing. But what is life without a few challenges.

The tank and seat are only tack welded together and there are various bits rough cut off of the frame. I will update this more when I can later but this is a slow project. January of 2018 is my planned finish date, so don't get to disappointed if I don't up date to to often, just a fair warning.

I have a 02 Kawasaki ZX7 front end I wanted to put on the bike, but the only way to do that is to swap the stems. I checked All Balls to see if their Fork Conversion Helper would have anything for me and it turns out you can't put this front end on anything but a ZX7 it seems. I ordered a front end from eBay for a 86 GSXR1100 (the right side up forks) and it is only a bearing swap away from sliding straight on. I have the wheels from a late 80s GSXR that I found on the side of the road in a pile of motorcycle parts with a FREE sign posted above it, along with the calipers to go with the dual disk brakes.

Along with that front end I have the swing arm from a 250 Ninja, and the shock and linkage from a late 90s GSXR600 I am going to mount to make this a Mono Shock.

Although I doubt I will get anywhere close to their level, CTLuba and 86broncbro are my inspiration, with their 3 cylinder mono shock, modern front end bikes.

Anyways, enough talking here are the pics of the bike when I first got it, I will upload more up to date pics later.
 

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Fuck it, let's do it live
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Re: 1973 GT750

That thing is badass!
 

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Re: 1973 GT750

Looks like early 72 cylinders on it....those are the easier ones to open up for bigger carbs.
If you want to build your motor up....
Contact this guy... Quickest GT in the land...
http://www.suzuki2strokes.com/forum/viewtopic.php?f=21&t=65&start=690
I've talked to him about getting mine set up.

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Discussion Starter · #8 ·
Re: 1973 GT750

Looks like early 72 cylinders on it....those are the easier ones to open up for bigger carbs.
If you want to build your motor up....
Contact this guy... Quickest GT in the land...
http://www.suzuki2strokes.com/forum/viewtopic.php?f=21&t=65&start=690
I've talked to him about getting mine set up.

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You are correct, I looked a little closer and it turns out my bike is a 72 frame and motor but it had the 73 and later dual disk front end so that threw me. I will get in contact with that guy you mentioned, my goal is about 100hp if possible. Looking closer it looks like the intakes have already been ground down a little to make room for bigger carbs. I will post engine pics tomorrow when I get a chance to do some work.
 

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Discussion Starter · #9 ·
Re: 1973 GT750

Ok so with the end of the school year (I am a teacher so that time is kind of busy for us) and then a longer then expected vacation right after I have not had much time to update the GT750. Thanks to the help of Busa1300 I did some closer looking and it turns out this is a 72 GT750 with a 73 and later dual disk front end.

Anyway I figure I can at least post some pics so you can see what I have got to work with.

So far I have "mocked up" (I use the term lightly) the Ninja 250 swing arm and GSXR600 shock and linkage. I am debating about using a GSXR swing arm I found on eBay instead of the 250 swing arm. The only real problem being the swing arm axle on the Ninja is pretty much the same as the GT where as the GSXR swing arm axle is huge (looking at using a 2000 and later).

The front end I have another dilemma. I have the ZX7R front end, but I would have to press the stem out and press in the GT750 stem provided I would actually fit, since you can't just do the bearing swap on the All Balls website for this front end on this frame. Or I can just do the bearing swap on All Balls and use the 1986 GSXR1100 front end I got but then I lose the aesthetics and performance of the much more modern and bigger front end of the ZX7R.

Anyways I appreciate any advice, and will try to keep this updated at least once a week during the summer, since all I got now is time.

The first pic is the free rear wheel I got off of the side of the road, I have the matching front wheel with dual disks and Nissin brake calipers to go with it.
The second not so great pic is the two front ends I have to decide from.
The third is a comprehensive shot of the bike now with the "mock up" of the swing arm and rear shock.
Pic four is the expansion pipes that the guy gave me. They are pretty dented up but are free plus shipping to a new home.
Pic five is a close up of the shock and swing arm.
 

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Re: 1973 GT750

Here is a post I did a while back on a stronger frame to handle 90-120HP
A stock frame can barely handle the 60HP a good stocker puts out... GT750 frames, especially the first off the line (early 72)were very weak and unbraced...great for collectors but not performance. The engines have rubber mounts, so no support through the engine. So brace the frame considerably if your wanting a 100HP motor with modern brakes, tires, and suspension. Otherwise all those modern parts will just flex the frame making all those good parts only marginally better. Which was why I was considering a different frame.
http://www.customfighters.com/forums/showthread.php?t=70218&page=2
At this point I'm planning on old school GSXR suspension, wheel, brakes, GS1100 swing arm, twin shock (It's an old school bike, so why not) along with some stiffening throughout the frame...So hopefully the frame will match the slightly better running gear. It might get used for vintage racing, which is why I'm going with 18 inch wheels (17's not legal for this bike class)

Heres a guy who went full modern frame....But to me it's like putting a full blown flat head Ford into a Mustang....it might work, but it doesn't have the same character
The project is well thought out and looks great though.
http://www.suzuki2strokes.com/forum/viewtopic.php?f=21&t=10396

Here is a guy that lives in Fort Wayne....I've seen this bike a few times down in Indy during the former MotoGP's a few years back
http://www.dotheton.com/forum/index.php?topic=47846.0
 

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Discussion Starter · #11 ·
Went and did some work yesterday and removed the cylinders and cleaned them up. Got all the bolts holding the cases together out and had to stop working before I could pull it apart. Anyway here are some pics.




This is the before cleaning pic.



This is one of the oil injection lines Jerry rigged. The previous owner I got it from claimed the bike ran. Sure in 1972 maybe. Check out the water pump cover next.


As it sits now.


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Getting those cylinders off can be somewhat of a bitch...looks like you took car of it pretty good
I've got an engine on the shelf that looks about the same condition....still need to strip it down yet
 

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Discussion Starter · #13 ·
Thanks I actually broke my tap I was using to tap out the stud holes in one of the stud holes, after that the cylinders actually came off fairly easy. I will post pics tomorrow of what it looks like now. Still up in the air about my over all end game. Going between upside down fork and mono shock and the GSXR1100 fork and dual shocks on the stock swing arm.


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subbed! gt750 is one of my dream bikes as well. Had a line on a tr750 and let that fall through the cracks.
 

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Discussion Starter · #17 ·
So did a quick mock up with the stock shocks and the GSXR front end. I Want a longer rear shocks and longer swing arm or by much just a few inches. I have a ninja 250 swing arm I could weld on tabs for the dual rear shocks since that would be way easier and cheaper then the mono shock upgrade. Any ideas?



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Well the go to cool dual shock swingarm seems to be kawasaki zrx...

I'll throw this out there, something like the ninja 650/versys could be cool and pretty straight forward. Shock gets a direct connection so there is no linkage to work out. Just weld mount to your frame...
 

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Discussion Starter · #20 ·
Well the go to cool dual shock swingarm seems to be kawasaki zrx...

I'll throw this out there, something like the ninja 650/versys could be cool and pretty straight forward. Shock gets a direct connection so there is no linkage to work out. Just weld mount to your frame...


I checked out the ninja 650 arm and I like that idea way cheaper then the ZRX arm just wonder if the stock GT 750 frame can handle the new loads from the mono shock? I am not an engineer so I don't know. Also does anybody know if a 2006 GSXR600 shock could be used for that, mainly since I already have one. Thanks.


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