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Toki
18th September 2022, 20:30
Does anyone know if there is such a thing as an electronic fuel injection system on a road motorcycle, that is not controlled by a computer?

jellywrestler
19th September 2022, 09:57
Does anyone know if there is such a thing as an electronic fuel injection system on a road motorcycle, that is not controlled by a computer?

what did the early GPZ1100 kawasakis run? by not controlled by a computer I am assuming you mean not able to be adjusted remotely?

pete376403
19th September 2022, 10:33
what did the early GPZ1100 kawasakis run? by not controlled by a computer I am assuming you mean not able to be adjusted remotely?
I read the GpZ system was an adaptation of a Datsun/Nissan analog car system and as no one seemed to know much about them the fix was to remove it and install carbs.

Grumph
19th September 2022, 11:39
I read the GpZ system was an adaptation of a Datsun/Nissan analog car system and as no one seemed to know much about them the fix was to remove it and install carbs.

Correct I believe as far as origins go. Yamaha did a domestic market 750 aircooled four with the same system. All of them brought in ran like shit and no one could do anything with them.
There was a guy here in ChCh who was tuning the early car systems in a very clever way. He had a dyno and exhaust gas analyser setup. The early car systems used a 4 or 5 segment throttle position sensor. A contact on a semicircular plate with segments touched as the throttle moved. He would put a pot resistance in the wires from the 2 segments at the bottom end and the full throttle position. Run it up on the dyno and adjust the pots to get the mixture strength he wanted. He told me most Jap cars were lean at the bottom and often over rich at the top.

What I suspect the OP wants is mechanical fuel injection. Rare on road cars and very rare indeed on bikes.

timg
19th September 2022, 13:47
Ignitech programable injection/ignition? Ignijet 12? Still controlled by a computer, but you can hook a laptop up to it and adjust the parameters to what you need or suits your bike. I looked at the Ignijet 1 Cyl when my Aussie under arm special was giving me grief with it's EFI. In the end I went with the cheaper carb option. Cheers.

https://www.ignitech.cz/en/vyrobky/ignijet/ignijet%201cyl/ignijet%201cyl.htm

pete376403
19th September 2022, 15:00
Correct I believe as far as origins go. Yamaha did a domestic market 750 aircooled four with the same system. All of them brought in ran like shit and no one could do anything with them.
There was a guy here in ChCh who was tuning the early car systems in a very clever way. He had a dyno and exhaust gas analyser setup. The early car systems used a 4 or 5 segment throttle position sensor. A contact on a semicircular plate with segments touched as the throttle moved. He would put a pot resistance in the wires from the 2 segments at the bottom end and the full throttle position. Run it up on the dyno and adjust the pots to get the mixture strength he wanted. He told me most Jap cars were lean at the bottom and often over rich at the top.

What I suspect the OP wants is mechanical fuel injection. Rare on road cars and very rare indeed on bikes.

Only mechanical petrol injection I know of is Lucas PI as used on Triumph cars. Would be fun adapting one of these to a bike - the pump used a large motor - same as a windscreen wiper unit. Injection pump was a DPA distributor type.

pete376403
19th September 2022, 15:03
Ignitech programable injection/ignition? Ignijet 12? Still controlled by a computer, but you can hook a laptop up to it and adjust the parameters to what you need or suits your bike. I looked at the Ignijet 1 Cyl when my Aussie under arm special was giving me grief with it's EFI. In the end I went with the cheaper carb option. Cheers.

https://www.ignitech.cz/en/vyrobky/ignijet/ignijet%201cyl/ignijet%201cyl.htm

If you're going to go that way look at Speeduino, uses an Arduino processor and again is laptop tuneable https://speeduino.com/home/

Toki
20th September 2022, 00:02
Thanks for the replies, folks.

I was wondering what currently available new bikes might have a simple controller for the EFI.

I'm trying to avoid ECUs if I can.

A point has been reached where I might have to decide to only have carburettored old bikes, or accept new and inscrutible systems.
I'm particularly scared of used machines with computers.

The Speeduino project looks good, but I'm not sure I want another hobby.

neels
20th September 2022, 09:34
Only mechanical petrol injection I know of is Lucas PI as used on Triumph cars. Would be fun adapting one of these to a bike - the pump used a large motor - same as a windscreen wiper unit. Injection pump was a DPA distributor type.
There was the Bosch K-jetronic, which used airflow to regulate fuel pressure to vacuum operated injectors, some minor electrics but basically mechanical, on lots of 80's euro cars.

Probably a bit bulky to put on a bike though.....
351732

Toki
20th September 2022, 10:03
My cousin had a Porsche 911 with Bosch mechanical fuel injection, similar to diesel type.
It was introduced to improve emissions compared to carburettors - without electronics hooray.
He said he never had a problem with it, although the car had high mileage when he bought it.

I think BMW K1 had K-Jetronic injection.