Help with small injectors

For discussing injector selection, manifold modifications, throttle bodies, fuel supply system design and construction, and FIdle valves and IACs.
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ovlovder
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Help with small injectors

Post by ovlovder »

So Im searching for some low rate injectors, seems around 8lb/hr. Or 86cc...

Converting my bandit 400, makes about 50hp stock, 4cyl...

Have been looking at scooter injectors, but can only find them new, like for the honda sh150...

Any ideas would be great.
24c
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Re: Help with small injectors

Post by 24c »

So you are looking for a single cylinder 100cc four stroke injector, I would suggest maybe a 125cc bike might be a better bet, In the UK we have Yamaha and Honda 125 singles that are power restricted. The Yamaha one is made in Thailand IIRC, so maybe that would be a good starting point or a Chinese copy!. The only problem might be you'll need a bank of four for your bike, and I imagine the throttle body centres are quite small too.
ovlovder
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Re: Help with small injectors

Post by ovlovder »

I have appropriately sized bodies.

Just need 4 injectors. Ive searched ebay.uk but dont know bike model names/numbers.... Ive also been looking at some tiny car injectors...
24c
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Re: Help with small injectors

Post by 24c »

There are several "motorcycles", Yamaha YBR125, XTZ125 both single cylinder, but Yamaha parts are expensive. There is also a Honda Varadero XL125 ( but this is a V twin with two small injectors), they also do a 250 IIRC.

A link to a used YBR125 one, although we are not supposed to do links, but it has a picture...
http://cgi.ebay.co.uk/YAMAHA-YBR125-INJ ... 89559909QQ
ovlovder
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Re: Help with small injectors

Post by ovlovder »

Ive found some vw polo injectors that I believe are the same rate(ish)

Am I better off with bigger or smaller than necessary?
dontz125
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Re: Help with small injectors

Post by dontz125 »

What you have to watch with high-revving engines is pulse width compared to cycle time. An injector that will supply plenty of fuel at 8000rpm may, on the same engine, run lean at 16000rpm.
ovlovder
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Re: Help with small injectors

Post by ovlovder »

dontz125 wrote:What you have to watch with high-revving engines is pulse width compared to cycle time. An injector that will supply plenty of fuel at 8000rpm may, on the same engine, run lean at 16000rpm.


My bike revs to 14000, is there more you can tell me about this? Or a link perhaps?
ovlovder
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Re: Help with small injectors

Post by ovlovder »

ovlovder wrote:
dontz125 wrote:What you have to watch with high-revving engines is pulse width compared to cycle time. An injector that will supply plenty of fuel at 8000rpm may, on the same engine, run lean at 16000rpm.


My bike revs to 14000, is there more you can tell me about this? Or a link perhaps?
Sorry for the double post, but,

Are pulse width and cycle time related more to tuning or are the injector attributes?
tubular
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Re: Help with small injectors

Post by tubular »

ovlovder wrote:I have appropriately sized bodies.

Just need 4 injectors. Ive searched ebay.uk but dont know bike model names/numbers.... Ive also been looking at some tiny car injectors...
Don't know if you are still interested.

Anyway, what are you using for throttle bodies?

I have converted my B4 succesfully using injectors from CBR600RR with the original bandit carbs as TBs. Check the MS Success Stories, Motorcycle board for a few details.

Here is the link: http://www.msruns.com/viewtopic.php?f=93&t=23094
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