GSX750F Engine in GS750 Bike

[TripleKing]

Has anyone here swapped a GSX750F engine (or an early oil-cooled GSXR750) engine into a late 70s GS750 bike? Ever since I got my 89 750F Katana (in a trade for an old Charger 2.2) I have been intrigued my the possibility of placing a sport bike 750 in an older, cafe racer eligible frame.

 

[hillsy]

The oil cooled engines will fit into the older GS frames easily - you have to make different engine mounts, but it has been done a gazillion times with GSXR1100 / 1200 Bandit motors into 1st gen Katana frames.

 

[TripleKing]

That might be my next project (once I sell one of my four bikes- I don't want a fifth bike), if I can score s decent 750 Katana engine and a decent GS750 or GS850. I know I will if I look around. Making motor mounts is not a problem for me. I just have this urge to make a sleeper. I wouldn't mind a Katana 750 engine into one of the crusier style custom bikes either. A quick quasi-bobber (I would keep the rear suspension) would be cool too.

 

[SONICJK]

Where are you?
Theres a full titled rolling gs 850 frame on CL in Nashville at the moment for 200

 

[teazer]

Has anyone here swapped a GSX750F engine (or an early oil-cooled GSXR750) engine into a late 70s GS750 bike? Ever since I got my 89 750F Katana (in a trade for an old Charger 2.2) I have been intrigued my the possibility of placing a sport bike 750 in an older, cafe racer eligible frame.

That's a new one. What is a Cafe Racer Eligible frame? Did someone list bikes that are eligible and do we now have an eligibility judge of some sort? Is a GS frame somehow more "eligible" than a GSX frame? I don't get that at all.

Either can be made into a stonkin custom bike. Sure, some GSX tanks and seats are a bit slab sided, but nothing that can't be fixed. What are you starting with and what are you looking to create?

 

[Big R]

Forget about the 850 frame - it's a shaft drive.

 

[SONICJK]

That's a new one. What is a Cafe Racer Eligible frame? Did someone list bikes that are eligible and do we now have an eligibility judge of some sort? Is a GS frame somehow more "eligible" than a GSX frame? I don't get that at all.

Either can be made into a stonkin custom bike. Sure, some GSX tanks and seats are a bit slab sided, but nothing that can't be fixed. What are you starting with and what are you looking to create?

I would wager he is looking at the frame line from tank to rear. Straight rear subframe a require a lot less work to make look "cafe" hence the remark.(as you well know haha)

 

[TripleKing]

Forget about the 850 frame - it's a shaft drive.

Forgot that. Come to think about it, weren't the 750 GL's also shaft drive?

 

[TripleKing]

That's a new one. What is a Cafe Racer Eligible frame? Did someone list bikes that are eligible and do we now have an eligibility judge of some sort? Is a GS frame somehow more "eligible" than a GSX frame? I don't get that at all.

Either can be made into a stonkin custom bike. Sure, some GSX tanks and seats are a bit slab sided, but nothing that can't be fixed. What are you starting with and what are you looking to create?

I.E. classic style universal frame rather than a box frame.

 

[hillsy]

Forget about the 850 frame - it's a shaft drive.

Actually, the shaft drive frames are more suited to wider swingarm swaps because the frames are wider than their chain drive equivalents.

A lot of Kwaka customs use the ST frames because of this.

 

[teazer]

Tripleking, I figured out what you meant. I was just messin' with you over the choice of words.

With 4's, they really fall into a later time period and usually look best in an AMA Superbike type look which is what race bikes and street bikes of that era looked like.

 

[TripleKing]

I like the look of the late 70s GS750.It has chain drive and similar looks to my 75 GT380, which I have (sort of) made into a cafe racer (bars and seat thus far). I think that style of bike looks goo with that theme. If I can give it some late 80s/early 90s go, that would be a plus. The late 70s GS75 engine made about 70-75 HP. The GSX750F engine makes about 100 HP. that is a nice pickup to have with stock reliability. Those engines can go to 100,000 miles and beyond with proper maintenance. It also has an air of sleeper about it as few people today would imagine a 1970s bike capable of such performance (out side of this and similar boards, of course). Heck most people I meet when riding never saw or even heard of my GT380 before. They do however recognize my Katana.

 

[jiveturkey79]

I'm about to be doing this swap. Swapping a 2000 GSX750F to my 1979 GS750. If anyone has done this swap, drop me a line, I'd like to discuss.

 

[jiveturkey79]

Here's my '79 GS750 with a the gsx750f engine in place. Along with my mounts that I made up. Just getting it welded up now.

 

[jiveturkey79]

I was able to use the existing mounts for the front of the engine.

 

[hillsy]

I was able to use the existing mounts for the front of the engine.

Ideally, you want the engine sprocket as close to the swingarm pivot as possible to minimize chain stretch when the rear suspension compresses.

 

[crazypj]

Forgot that. Come to think about it, weren't the 750 GL's also shaft drive?

Never heard of a 750 GL?
For Suzuki only,
G = shaft drive
L = 'low rider' (or custom)

I really like the SACS motors, I think I have almost all the bits needed to build an 1100 into a 600 crankcase 8) (bore spacing and main bearing diameters are the same for 599cc and 1074cc ) Big end journals are bigger on 1100 motors ;D

The only thing that bugs me about the swap is the swing arm pivot should be re-located closer to final drive sprocket, particularly if your mounting engine further forward. Must be close to 8" between the two 'pivot points'?