Motorcycles

hybrid · Post by **hybrid** » Fri Jun 09, 2006 8:56 am

You could always lower the fuel pressure slightly.

mrbell · Post by **mrbell** » Fri Jun 09, 2006 11:56 am

wouldn't that compromise atomization?
Come on... there has to be a 100cc injector out there somewhere...

keithmac · Post by **keithmac** » Fri Jun 09, 2006 12:27 pm

I was going to say you could try an EFI moped set-up, but most work differently to normal EFI, they use a small air pump driven off the crank which forces the fuel/ air into the cylinder.

Gilera do a single clyinder EFI 250 engine, maybe wother a look?

racingmini_mtl · Post by **racingmini_mtl** » Fri Jun 09, 2006 12:51 pm

mrbell wrote:My bike is a 350cc inline twin and only makes 35hp.

If you look at injectors from a small car with a 4-cylinder engine you should be able to find something. If the car makes about 70HP then the injectors are perfectly suited for your engine.

Even bigger injectors should not be a problem if not overly large. For example, 14lb/hr injectors are quite common and are about 50% more than what you need but should be tuneable. And if needed you could lower the pressure a bit without affecting the atomization too much.

Jean

mrbell · Post by **mrbell** » Fri Jun 09, 2006 3:14 pm

I was thinking a swift's or metro's injectors might work... but even they seem to be about 170cc/min. I might look into a Toyota Paseo, but there just aren't that many sub 100hp cars around...

hybrid · Post by **hybrid** » Fri Jun 09, 2006 6:04 pm

The GPZ1100 injectors should work for your application.
The TB's are only 32mm, so you couldnt have massive injectors in those.
In saying that, I dont know exactly what cc they flow.

Lowering fuel pressure too much could affect atomisation, but a little shouldnt hurt. Depends how low you would need to go I guess.

jharvey · Post by **jharvey** » Sat Jun 10, 2006 1:38 am

mrbell wrote:wouldn't that compromise atomization?
Come on... there has to be a 100cc injector out there somewhere...

As luck has it, I'm working on a smaller engine project. I posted about two small injectors here.

http://msefi.com/viewtopic.php?t=19550

I'm actually hoping for 50cc/min but what can I do. These are the smallest I've been able to get so far.

whittlebeast · Post by **whittlebeast** » Sat Jun 10, 2006 3:50 am

What are you running this on? Guess the HP and RPM please. 50 cc sounds small. I run 2 X 800 cc injectors on a 800cc two stroke two cylinder jetski. These high RPM small displacement motors get out of hand.

AW

Skiericski · Post by **Skiericski** » Sat Jun 10, 2006 6:12 pm

What other external pumps have been used on a motorcycle install? Those GPZ pumps are hard to find used, and are likely pretty pricey new.

jharvey · Post by **jharvey** » Sun Jun 11, 2006 2:09 am

whittlebeast wrote:What are you running this on? Guess the HP and RPM please. 50 cc sounds small.

I'm working on an 8HP Briggs 1 cyl. The mega manual says 4.7lb/hr or 49cc/hr. I'm mostly concerned about idle with a 100cc/min injector. I'm hoping to play some pushing the power up, so I'm not to concerned with it running at around 40% duty.