GSX750ES engine conversion

[Ravivos]

Hi All,
My name is Raviv and i live in Israel.
have been riding for almost 20 years now, and built a bike or two.
recently, i bought a 84' GSX750ES and i am gathering parts for it, converting it into a lean, mean, naked machine.
already got an RGV front end and have a set of spoke rims off a supermoto motorcycle (EXCEL rims), i have a BMW 800F front center hub to accommodate a twin 300mm rotors with a NISSIN calipers.
i was thinking of swapping the engine with a bandit 1200 engine, have searched this website but couldn't find any info about it... i can fabricate engine mounts, can TIG weld and know my way around a wrench.
can someone direct me to a link or a thread showing the work involved in such a conversion? would the 1200 engine fit into the 84' ES frame? how about engine alignment? any other structure reinforcement needed?

any help or ideas are welcomed.
thank you.
Raviv.

[hillsy]

I don't think an 1100 GSXR motor is physically any smaller than a Bandit motor. Plus a Bandit motor would be easier to find and being newer it would probably not be needing a rebuild.

I know the 750ES motor is smaller than the 1150 motor, so a GSXR / Bandit motor would probably be a good fit in that chassis.

[Ravivos]

Hi isleoman,
thanks for the links, it will surely help getting me on track.
as for engine choice, there are a few guidelines that i want to keep - air\oil cooled, no frame chopping and 4inline engine... other than that, there is a matter of availability as the bandit 1200 engine is a bit more accessible where i live.
although i already have the RGV front installed, i am considering (since the opportunity poped up) going with a 2005 gixxer 1000 front, i can get the entire front section including the 17" wheel for a decent cost.
the 16" original front wheel is... well... lacking, i guess.

Hi hillsy,
good to see you here as well , thanks for the info.


Raviv.

[kingofvenus]

It's been done many times. I'm in the middle of swapping a '89 short stroke 750 (dot head) into mine. Had to relocate the fuel tank petcock to the rear of the tank, and section the area of the tank an inch to clear the top of the carbs. Others have gotten by with raising the tank at the rear. Here is a picture of mine with the stock engine in it, It's in many pieces as we speak...

[Old guy]

Don't forget the Katana motors either. You might have an easier time finding an 1100 Katana motor vs a GSXR.

[kingofvenus]

Some later 1100 gsxr's had 1100 kat motors in them, had some left over, dirty little secret of the factory. Bigger motors than the 750's will fit and has been done by many. It's the carbs hitting the bottom of the fuel tank and the petcock.....

[RedLiner1100]

Here is an excellent build thread on Custom Fighters where a guy put in a Bandit 1200 in a early 750 frame.

http://www.customfighters.com/forums/showthread.php?t=101833&highlight=timeslip

[Ravivos]

Well...
started working on the 750 engine, converting it into EFI using microsquirt, and all the sudden, out of the blue, i manage to get a hold of a 2001 (i think) GSF1200 engine.
so, i guess i will be swapping the 750 with the 1200, and it will be EFIed as well.
my question is - did anyone did such a conversion? GSX750ES with a GSF1200 engine? if so, can anyone link me to a build thread so i can see what is needed?
will the 1200 fit into the 750's frame easily? will i need to build some new mounts for it? how about the sprocket alignment with the rear wheel ?
any help and info will be much appreciated.

Thanks.
Raviv.

[XR750]

There's a good build thread on this site titled: 82 GS750E to GSXR1215 restomod

[akckhim]

The 84 is a little different than mine. But it should go in there maybe a couple of new mounting plates will be needed.kingofvenus should be able to help you.

[Ravivos]

Thanks all for the info,
guess i'll just have to start with trying to mount the GSF1200 engine into the GSX750ES frame... have no problem fabricating some new mounting plates and even some TIG welding, my main concern is that the engine will just not fit into the frame.

As for the EFI conversion, i will assemble the parts that i got so far onto the GSF engine, should be rather easy.
i really hate carbs, and the EFI solution is fantastic.
yesterday, manage to get a proper sync signal from the 36-1 trigger wheel, VR sensor and Microsquirt connected to a laptop... thats a good progress and now i need to conclude the fuel system (waiting for parts) and some additional wiring.

will continue updating as i go, and as usual, any information and opinion are welcomed

[akckhim]

The bandit/katana/Gsxr oilcooled engine is smaller than the aircooled

[Ravivos]

Hi akckhim.
your GS is fantastic, and the build thread is very informative.
well, my 84' is the GSX750 , with the square tubing frame, it is also oil cooled... i hope the GSF engine will fit.

[akckhim]

Thanks for the kind words. I think you will surprised by how easily it will go in.

[kingofvenus]

That motor will go right in. Just need to fab up mounts. Going with EFI will probably take care of fuel tank clearance issue....