fuel pressure regulator

Can anyone recommend a fuel pressure regulator to fit a 1982 GPZ1100 B2, it doesn't have to be anything special it just has to work and not be too large.

Thanks

Fuel Pumps & Regulators
www.fuel-pumps.net/gsl393.html
www.mpsracing.com/products/MPS/FuelPumps.asp
www.airtexproducts.com/

Hi:

I have this Bosch adjustable pressure regulator on my '81 GPz1100. Sorry that I can't be specific about it, because it's undercover (and buried) in my garage, but there's one out there for you. It wasn't the easiest fit. I re-used the stock bracket and put it on the opposite side of the crossbar that it was normally mounted on. Ran longer screws though it so they poked out the other side, and put washers and lock nuts on the exposed threads. I had to shorten that pressure relief hose (vertical one) that goes to the tank too. It pushes in slightly on my airbox too, but that's no big deal.

Bike runs much much better with the extra PSI you can dial in.

I think that they are around $40.

Good luck.

Marty

Re: 1982 GPz1100 Fuel Injection Modifications
From Cavanaugh Racing
They run fine without the air box if you use the adjustable regulator. For a full on race setup, nothing beats the stock rubber velocity stacks that connect the air box to the throttle bodies.

Stock throttle bodies with the rubber stacks flow 125 CFM. Kawasaki knew what they were doing when they designed that system.

If you're going to keep the bike stock, leave then air box on. If you modify it for performance later on, you can go with individual air filters if you so choose.

If it were mine, I'd find some 83-85 GPz11 cams for it and drop them in. No need to switch to Shim on Bottom. They are the single item that will bolt in and provide immediate performance gains with nothing more than a valve adjustment. They're still out there and available for reasonable price. You'll want the adjustable regulator if you go that route.

If you go the adjustable regulator route, use the TPS adjustment to clean up the bottom end and make it idle smooth. Drill out the DFI cover plugs [carefully]. Remove the plastic cap. You'll see 2 phillips head screws with yellow paint on them. Warm up the bike. Set the idle to 1100 RPM. Adjust the TPS to where you have the highest, smooth idle & lock it down. Then reset the idle to 1100 with the main idle adjuster screw on the TB. That procedure applies to a bone stock bike as well. It's the best way to dial in the bottom end of the fuel curve. The little electric gizmo you see in the service manual for adjusting the TPS is good for taking up space in a drawer .

Kawasaki GPZ1100 TPS Replacement

Being as it doesn't have an O2 sensor for fuel correction and the computer doesn't allow for enrichment your assumption would be correct. The Kawasaki Turbo is your friend here, for the variable resistor wired inline to the temp sensor circuit. Ask the guy whose had four of them. Do a Google using the turbo instead of the GPz. I think Holeshot Performance made one.

MPS Racing made a variable resister for the GPz1100 DFI. They don't show it on their website, e mail or call and ask for it. They'll still put one together.
www.mpsracing.com/


KZr Forum
Technical Forums
Carburetor
Interesting fuel mod on my GPz1100 DFI (long)
Polar_Bus

Hi all,
Basically since I aqquired my GPz1100 back a few years ago I've been experiencing what seemed to be a lean air/fuel condition.

I systematically checked all "mechanical" type issues, and everything seemed to be in good working order. As I started getting feedback, and an understanding about the "crude" DFI design and the current usage of EPA friendly oxygeynated E10 fuel, I began to realize that I'm thinking I simply have a "too lean" fuel map.

My bike always had a lean stumble around 3000-3500 rpms. Unfortunately there's not a lot of info or hardcore experiences about modifying the stock GPz1100's ECU. However a member of another forum who previously owned a early Kawi Voyager DFI (same inherant lean condition) schooled me on a neat trick dubbed the "680 Ohm resistor mod". What some genius figured out was to splice a resistor into the air temperature sensor circuit to "fool" the ECU into thinking the air temps were slightly colder that it actually was, which in turn would slightly richen the air/fuel mixture. I tried a 680 Ohm, and quickly realized this made my GPz run a bit too rich. I opted to try a 1K Ohm resistor, and now I made positive progress, my bike really runs awesome !

Gone is the low to midrange hesitations, and seems to pull hard right up to redline. I am going to maybe try a few more resistors, or possibly fabricate an adjustable "potentiometer" type device to adjust "on the fly" over the winter. I'll keep updating this for other GPz1100 members as an FYI. Here's a few pics of this simple and effective mod:

And here's everything all spliced in (no hacking required, as I used male and female spade connectors to plug into the OEM connectors)
That's neat, putting a pot on there would look really cool too.

Now that is a great mod! I had grown to accept the 3500-4000 rpm stumble in my brand new 1982 GPz1100 back in 1982...fast forward 25 years in my recently acquired 1982 GPz1100 and its inherent stumble at that rpm

You can get the resistors right at your local Radio Shack, so give it a try on your "B2" . Best thing is if you don’t like the results, just yank the resistor back out ! No permanent damage or hacking done ! You start opting for "modified" ECU's and mechanical fuel pressure regulators in an effort to richen, now you are getting into more "permanent" type modifications (and expensive). A 4 pack of Radio Shack 1K Ohm resistors is $.99

H...splice a resistor into the air temperature sensor circuit to "fool" the ECU into thinking the air temps were slightly colder that it actually was, which in turn would slightly richen the air/fuel mixture. I tried a 680 Ohm, and quickly realized this made my GPz run a bit too rich. I opted to try a 1K Ohm resistor, and now I made positive progress, my bike really runs awesome ! Gone is the low to midrange hesitations, and seems to pull hard right up to redline....

If adding 680 ohms resistance made it too rich, seems like adding 1000 ohms resistance would make it even richer?

Polar_Bus wrote:
H...splice a resistor into the air temperature sensor circut to "fool" the ECU into thinking the air temps were slightly colder that it actually was, which in turn would slightly richen the air/fuel mixture. I tried a 680 Ohm, and quickly realized this made my GPz run a bit too rich. I opted to try a 1K Ohm resistor, and now I made positive progress, my bike really runs awesome ! Gone is the low to midrange hesitations, and seems to pull hard right up to redline....

If adding 680 ohms resistance made it too rich, seems like adding 1000 ohms resistance would make it even richer?

The air temp sensor alters output voltage ranging from 1.7-3.8V . The warmer the ambient air temps are The lower the output voltage, and vice-versa. So my goal is to effectively slightly raise output voltage. To my understanding this is done by increasing the rated ohm output of the resistor ? Geez, I hope I’m doing this right !? LOL

There is a system sold for that. That is tuned for every individual model bike. I bought one for my bike about a year ago. I paid about $7 for mine. I figured out later that installing a adjustable fuel pressure regulator was a better way to go.

Larry cavan wrote:
Old trick from the mid 80's finds new life in the next century

You have two choices to fatten up the fuel curve on a stock Kawasaki DFI from those days.

1 - Air temp sensor Resistor
2 - Adjustable Fuel Pressure Regulator

For a mild street motor the air temp sensor works very well.

For anything that would require main jet increase on carbs, the FPR is the ticket.

If you really want to wake it up, send the throttle bodies to Sid Pogue at Pogue Machine in Oklahoma City. Well worth having done.

question about air temperature sensor mod.

I believe that if you add higher resistance, 1k Ω instead of 680 ohms, the mixture will be richer.
The manual mentioned that the lower temperature result in higher resistance.
0°c = 4.7 to 7.6k Ω
20°c =2.0 to 3.0k Ω
30°c=1.4 to 2.2k Ω
That tell you if you add more Ω to temp sensor, the ECU thinks the temperature is lower and gives you richer mixture.
I'm I correct? :silly:

I have been dabbling with my 1982 KZ1100B2 which I have put the resistor mod on and a variable pressure regulator. 

The bike starts, revs high; pushing a plume of white smoke out the exhaust pipe and stumbles when the throttle is opened.  I have played with the throttle position sensor and got the idle to stabilize; however, I am thinking the variable pressure regulator is the cause of this.  The pressure gauge's needle is bouncing all over the place. 

Is there an OEM Pressure regulator available that's a direct replacement for the stock one?

For example, the fuel injectors from a Datsun are a direct replacement for fuel injectors in the bike.  No, I can't find the old one.  

diego092409 wrote:

I have been dabbling with my 1982 KZ1100B2 which I have put the resistor mod on and a variable pressure regulator. 

The bike starts, revs high; pushing a plume of white smoke out the exhaust pipe and stumbles when the throttle is opened.  I have played with the throttle position sensor and got the idle to stabilize; however, I am thinking the variable pressure regulator is the cause of this.  The pressure gauge's needle is bouncing all over the place. 

Is there an OEM Pressure regulator available that's a direct replacement for the stock one?

For example, the fuel injectors from a Datsun are a direct replacement for fuel injectors in the bike.  No, I can't find the old one.  



 

I bought a used adjustable fuel pressure regulator off Ebay that was originally off a Porsche 914, it looks to be of similar size and function to the GPZ1100 unit.



I have not used it yet as my DFI build is a long term project : www.kzrider.com/forum/11-projects/619531...injection-conversion

Not sure exactly what year its from but they had a narrow production window.
 

marknir wrote:

Can anyone recommend a fuel pressure regulator to fit a 1982 GPZ1100 B2, it doesn't have to be anything special it just has to work and not be too large.

Thanks


Pretty sure I have a stock one from an 83 > If you think it will help I can send it to you.