TOPIC:

I have heard that GPZ 1100 1984 Throttle bodies are a direct bolt on, but someone said that you can adapt GSX throttle bodies onto the Z using J rubber intake boots- anyone know about this? I posted this on another site for those that browse around these boards- but I need to know fairly quickly so I can bid on the right ones on e-bay?

One of the guys on my site has done it on a 750 turbo head, which shares the same inlet spacing as the 1100 (and yes you can use 1100 TBs on the 750). He machined back the inlet ports as far as possible and machined new ones out of alloy, welded them on, blended in the ports with a grinder and bolted on the Suzuki TBs with Suzuki inlet rubbers. He got it started and running but sold the lot before going any further. One thing to bear in mind when you crack the throttle with such big bodies is that the mapping will be miles out, possibly too far out for a Powercommander to correct, so you might need an ECU with an accelerator pump function to make it run right.

By the way, it's the 1100 bodies that fit with J model boots. You need to slot the bolt holes in the boots as they are wider apart than the 750 boots, you can then fit them with a smear of Threebond and once dry open up the inlet ports a little to match the bigger boots.

Lorcan wrote:

One of the guys on my site has done it on a 750 turbo head, which shares the same inlet spacing as the 1100 (and yes you can use 1100 TBs on the 750). He machined back the inlet ports as far as possible and machined new ones out of alloy, welded them on, blended in the ports with a grinder and bolted on the Suzuki TBs with Suzuki inlet rubbers. He got it started and running but sold the lot before going any further. One thing to bear in mind when you crack the throttle with such big bodies is that the mapping will be miles out, possibly too far out for a Powercommander to correct, so you might need an ECU with an accelerator pump function to make it run right.

Can you e-mail me at This email address is being protected from spambots. You need JavaScript enabled to view it. please- I have not even laid eyes on these TBs before, and I am wondering, if inlet size is close enough, and spacing is wrong, what is entailed in simply changing the spacing in the TBs? I know you brits and Euros are light years ahead of us in modding old bikes- and I am really wanting to get moving on retro-fitting old bikes with EFI on all kinds of models- but I want the hardware to be reasonably straight forward and not waste too much money on the first attempt- know what I am saying Lorc? I plan on using Mini-mega-marine squirt as far as mapping goes.

Your best bet on any KZ is just to use the 1100 bodies, the Gixxer bodies were an experiment, I have no idea if they will work well or not. Learn to walk before you run eh?

The GSXR 600 bodies fit in the J model carb holders, I have a set of bodies and the J manifolds and tried it.

Check out this thread in the injectors fuel and air supply forum on the msefi site.

ZRX1100 with GSXR throttle bodies and MegaSquirt

GSXR throttlebody spacing modification pics

Post edited by: steell, at: 2006/08/06 15:32

here's one that has my stumped, steel...

i thought i found once where the MS will work with a dyna-s ignition, and for the life of me, i cannot recall where i saw that.

any recollections guys?

***EDIT***

strike that. i just remembered something else, and that will work out JUST fine. skip running the spark control, and just use the MS for fuel. much simpler.

--r

Post edited by: solomrus, at: 2006/08/07 10:16

So many good posts- thanks guys!

I may have a set off a gpz750 or gpz1100, not sure. PM if you'd like me to measure when I'm at the workshop again. It will be a week or so. Going treasure hunting in old bone yard tomorrow AM. Supposedly untouched for past 15 years. Can have a look around there too.
-Duck

If you decide to go bigger than the GPz1100 bodies (35mm) make sure you have enough meat in your inlet ports to open them out to that size. You don't want a step in the inlet, and you need to leave enough material to make a good seal.

Here's my 750 ports, the one on the left is opened up to suit the 1100 body, I'm not sure it could go another 3mm. Maybe on an aspirated bike, but not on a turbo.

Duck wrote:

I may have a set off a gpz750 or gpz1100, not sure. PM if you'd like me to measure when I'm at the workshop again. It will be a week or so. Going treasure hunting in old bone yard tomorrow AM. Supposedly untouched for past 15 years. Can have a look around there too.
-Duck

I have a bunch of measurements off the MSEFI site- you have PM- are you looking to get rid of the EFI stuff?

The quoted spacing for the GPz1100 that was on the MS site was incorrect, I don't know if it was corrected though, read the whole thread to see.