1984 GPz 1100

Hi Guys, I am new to the forum hope we can help each other out. Just picked up a 84 GPz 1100 Fi. It's be sitting for many years and it only has 2,300 miles. Fuel pump is shot. Also 3 fuel injectors are bad. I here that good FI parts are scarce and expensive so I will be converting over to 34 Mikuni carbs off a 83 Gpz 750.Will clean the carbs in a ultrasonic cleaner,but need to know what jetting to use. Stock airbox or pod filters? If I go with pods what about a Dyna jet kit .I work in a shop that rebuilds old Triumph twins and triples. Even though the GPz is 30 years old its still light years ahead of a old Triumph

just get the fi cleaned out. You can get a fuel pump and clean the injectors. Nothing runs better than kawi fuel injection. Its not that hard to get it back in shape.It will be cheaper and run much better than the carbs.

Have to agree that in principle I don't see where repairing the DFI will be much harder than tuning a set of stock 750 carbs to work on the 1100.

Fuel pump was used in automotive applications (mine has an 80's subaru turbo pump on it). I am a bit surprised that 3/4 of the injectors are "bad." Maybe need cleaned?

riturbo wrote: just get the fi cleaned out. You can get a fuel pump and clean the injectors. Nothing runs better than kawi fuel injection. Its not that hard to get it back in shape.It will be cheaper and run much better than the carbs.

GypZee wrote: Have to agree that in principle I don't see where repairing the DFI will be much harder than tuning a set of stock 750 carbs to work on the 1100.

Fuel pump was used in automotive applications (mine has an 80's subaru turbo pump on it). I am a bit surprised that 3/4 of the injectors are "bad." Maybe need cleaned?

I agree, I doubt the 3 injects are broken. I would send them all out to get cleaned. Fuel pump is cheap. PS (to OP) how do you know its broken?

But I do agree with riturbo, I would sooner fix the DFI before going to carbs. Jetting 4 carbs to perfection including balancing is a pain in the ass, then you would have to mess around with the throttle cable, get pods, a host of jets, etc. I have a variable resistor on my GPz's air temp sensor, I can dial in the fuel in seconds and while riding! I'm quite happy with the DFI over carbs.

Thanks for the response.I dont doubt the fact that the orginial f/i can be made to work.But the bike has been out of prodution for close to 30 years. I did p/u a working fuel pump and a complete f/i system on e-bay at a reasonable price and installed it but no cigar. You have to ask yourself why it was removed in the first place.I think that carbs off of a 83/84 Kz 1100 may be the way to go.Intend to run a airbox with stock exhaust.Will install Stage 1 Dyna jet kit,and i have a ultra-sonic carb cleaner to get all the crap out of the passage ways. The bike sat for many years and whatever gas that was in the tank really turned nasty.The only reason i bought it was because of the low mileage 2300 to be exact and the fact that its a real challenge.It could turn out to be a dud!Live and learn . Jeff

Do yourself a favor and keep the DFI once working properly you will love it.

Work with the DFI.
If you have good electrics then the injectors can be cleaned and the fuel pump can be replaced.
Check my other posts, the pump and fuel relay I have used is listed in them.
Biggest issue with DFI is dodgy connectors in the wiring.

Get the workshop manual from ebay seller pumpkin874. I bought one a couple of weeks ago.

Working in a bike shop you should have all the tools and equipment to get it going in short order.

The limitation of the original FI is the lack of tuneability for racing, correct me if I'm wrong.

Don't be afraid of the black box, it doesn't bite,
I have not had any issues with the FI computer. I did buy two more used ones, for backup, and have swapped them in, to test them. They are all working soundly.

Statorhed wrote: Thanks for the response.I dont doubt the fact that the orginial f/i can be made to work.But the bike has been out of prodution for close to 30 years. I did p/u a working fuel pump and a complete f/i system on e-bay at a reasonable price and installed it but no cigar. You have to ask yourself why it was removed in the first place.I think that carbs off of a 83/84 Kz 1100 may be the way to go.Intend to run a airbox with stock exhaust.Will install Stage 1 Dyna jet kit,and i have a ultra-sonic carb cleaner to get all the crap out of the passage ways. The bike sat for many years and whatever gas that was in the tank really turned nasty.The only reason i bought it was because of the low mileage 2300 to be exact and the fact that its a real challenge.It could turn out to be a dud!Live and learn . Jeff

Go to 750turbo.com . All the info to fix your bike is on there. The turbos have the same set up . Just do a search on cleaning injectors. If you still have problems ask. Lots of guys on there who know how to fix anything wrong with your bikes injection system

Are the injectors in fact getting a signal?
Have you tested at the connector with a bulb?

There are better injectors available. RC Engineering should be able to hook you up and/or clear yours. I guarantee that if they're good, cleaning them will work wonders.

With an adjustable pressure regulator and adjusting the TPS, the OEM DFI can be tuned for about any scenario you're going to throw at it, including completely removing the air box if you choose.

crh wrote: Are the injectors in fact getting a signal?
Have you tested at the connector with a bulb?

There are better injectors available. RC Engineering should be able to hook you up and/or clear yours. I guarantee that if they're good, cleaning them will work wonders.

With an adjustable pressure regulator and adjusting the TPS, the OEM DFI can be tuned for about any scenario you're going to throw at it, including completely removing the air box if you choose.

Agreed, crh comments and the others are sound. The dfi is pretty pimp. It's crude enough you can pass around with it using the tricks described above and not as fancy as today's with o2 sensors and cpu's. The best part is you never have to screw around with jets on 4 carbs.