Gix11

How to "make a water cooled GSXR 7/11 "

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How to "make a water cooled GSXR 7/11 " - Submitted by Deano (Dean Molloy)

I am sure we all know the benefits of the almighty GSXR7/11. The most common 7/11 swap is done using the earlier oil cooled (before 1992) GSXR.

This conversion on water cooled models is not as popular as the oil cooled and information is harder to come by so I have put this guide together for anyone thinking of doing this conversion also.

Frame:
Both the 750 and 1100 frames share the same mounting brackets and holes for the motor. I used original 750 mounting bolts and engine mount brackets. The frame does not need any modification to make the motor fit.

Exhaust:
I choose to use the 750 exhaust because that is what I had. When mounting the exhaust I struck a couple of problems. The reason for this is simple, I was using an exhaust suited to a shorter motor and because of this the clearance to the sump was very small. As I was fitting the exhaust I had to modify a couple of things, There is an M6 bolt in the front of the sump, this was hitting the exhaust so I changed it to a Stainless Steel button head cap screw. This type of bolt gave me a smaller head and gave me a couple of mm of clearance. ( see photo)

The rear exhaust mounting bracket under the bike had to be modified. The exhaust was sitting higher and forward slightly more with the 1100 motor in place therefore the bolt holes didn't line up. A quick cut, weld and spray paint and that was fixed .( see photo)

(A better combination could be to run and full 1100 exhaust, sump and oil pick up.)
photo shows the tight fit between sump and exhaust and also the modified exhaust bracket under the frame





exhaust to sump clearance







modified exhaust bracket




Oil Cooler:
Originally the 1100 came out with a separate air to oil cooler mounted in front of the motor below the radiator, whereas the 750 had a water/oil heat exchanger mounted between the oil filter and engine block.

I chose to run the complete 750 cooling system. This meant removing the heat exchanger from the 750 engine block and screwing it into the 1100 block. Fortunately I was able to pick up a complete 750 engine with carbs from ebay for a reasonable price, this meant that I didn't have to rob parts from the mint 750 motor that just came out of the bike.

To remove the heat exchanger you just unscrew the filter and then you will see a larger nut that holds the heat exchanger onto the block. Unscrew the nut and the heat exchanger will separate from the engine block.

To fit the 750 heat exchanger to the 1100 motor requires you to remove the threaded sleeve that the oil filter screws to. I welded a bolt to this sleeve and then put a spanner on the end of the bolt and unscrewed the sleeve (see photo)
You then refit the 750 cooler to the 1100 block (best to use a new 0-ring to seal any potential leaks)

Photo shows 750 heat exchanger and 1100 oil cooler





750 heat exchanger









1100 oil cooler








Oil Cooler Adapter




Radiator:
The Radiator and thermo fan assembly I used was a 1100 unit (750 will fit as well ). The only problem I had with that was the lower radiator mount bracket. Because the exhaust was higher and forward more than before the exhaust headers hit the bottom of the radiator and the thermo fan cowling.

To get around this problem I put some spacers and longer bolts in between the frame and the lower radiator mount bracket. This was just enough to stop them touching.
Photo shows the temp alloy spacers between the bracket and frame

lower radiator bracket spacers



Radiator hoses/pipes.
As I was using the 750 cooling system this meant that both the front and rear alloy water pipes had to be changed to 750 items. The 1100 radiator cap and thermostat housing sit on the side of the motor whereas the 750 has them located underneath the fuel tank.

The photo shows the difference in radiator hoses between 1100 and 750 and coolant pipes. when fitted to match up the 750 cooling system the 1100 coolant pipe is facing the back of the bike and not the front






750 coolant pipe fitted to 1100








750 front water pipe






1100 coolant pipe fitted to 750 motor







Induction/ Carbs :
I chose to use the 38mm 750 carbs on the 1100. They fitted directly into the 1100 inlet rubbers and have the same spacings. Because of the larger capacity the carbs have to be jetted up to suit the 1100 motor. The main jet went from a 115 to 142.5 and the 750 needle can't be adjusted rich enough therefore a replacement richer needle or dynojet /factory pro jet kit would have to be installed. I had to grind away the back of this bracket (pictured ) to stop the carb caps from hitting the frame on each side.
The 750 air box will still fit but I chose to use BMC pod filters

Photo shows the back of the bracket mount that had to be modified to clear the carb caps



711 carby cap clearance










pod filters











Sump:
As I was using the 750 exhaust this meant using the 750 sump and oil pick up. The 750 sump has a large bowl on the left as the exhaust runs down one the right hand side.
(A better combination could probably be a full 1100 exhaust/sump and oil pickup combination)
the photo shows a ‘modified' 1100 sump and a standard 750 sump fitted to an 1100




1100 sump










750 sump










Engine Mounts:
Stock 750 or 1100 mounts will fit and either can be used

Electrics:
I used my original 750 wiring loom and CDI box. The downfall with this is that the rev limiter for the 750 is set about 3000 rpm higher than the 1100 unit. The 1100 CDI I had wouldn't work on the 750 loom.

The rev limit on the 750 CDI can be lowered by a company in Geelong Victoria call Small Coil Rewinds (03) 5278 8454 for $130

Gear Shift/Clutch:
The 750 and 1100 gear levers are different. I used the 750 unit and the clutch cover had to be modified to make it fit as the lever that attaches to the gearbox selector shaft hits against the clutch cover.

The 750 has a cable clutch therefore you will have to change to a Hydrolic clutch. I used a ZX7R master cylinder and original 1100 clutch hose.




modified clutch cover












ZX7R clutch master cylinder











Finished product:
After completing this modification the main difference is the lazy power that the 1100 makes. It has a chunky midrange that tends to make you very lazy on the gearbox. Performance results for the 750 before the modification tested with a Veypor VR2 datalogger were
0-100kph 3.77sec in 51m
1/4mile 11.95sec at 180.40
and 71.7hp at 10204rpm
performance data with the 1100 motor will follow soon
this photo is of the bike once completed



711











Disclaimer:
This information is true and correct for my model of bike and I take no responsibility if the information above is not true and correct for your model of motorcycle. You should always contact your local traffic authority before performing such a modification. YOU HAVE BEEN WARNED - DON'T BLAME ME
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