MicroSquirt.com read only forum (Jan.15,2018)

BrentP wrote: On my 650 twin I am running about 400cc/min injectors.

please tell me that is of the XS variety!!!!

Sorry, too many valves...

It is a Suzuki SV650.

So... how much power do you intend to make w/ your bike?

Been racing it for 3-4 years now.

Stock was 63hp
All work done with 41mm FCR carbs was 82hp
Replacing FCRs with 46mm TBs and MSI gives 94hp

It goes like stink, too bad the rider stinks too.

So how did you decide that you need 800cc/min injectors? All the math I'm doing says two 300cc/min injectors will do you just fine. It should be able to get all of the fuel you should need in the cyl to get 12:1 at 11500rpm.
and 2 300cc/min injectors will be more than enough support 100hp...

Skiericski wrote: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.

Well, I think that there is many suitable pumps available, for example smaller Bosch models should be fine. I just replaced my GPZ pump with Mallory 4060FI and it seems to be quite nice alternative. It's almost the same size, draws only slightly more current and provides much more flow.

mrbell wrote:Another question I just thought of... what about power? Most bikes I've been on have trouble keeping a headlight on at idle, how will you run an EFI system?

That's my concern too - specifically draw of the fuel pump. Anyone have hard numbers on what a few of the popular pumps draw? I have a preference for the returnless GSXR pumps, for simplicity's sake (and keeping my 30 yr old gas tank intact.)

In my case the victim is a Honda CB550 - way low in the alternator output department. Maybe I'll just keep the headlight off?


Other concerns - where to put the darn O2 sensor in the lovely 4-into-4 system (no collector!), but thats another question for another thread.

-Chris

bdjuju wrote: In my case the victim is a Honda CB550 - way low in the alternator output department. Maybe I'll just keep the headlight off?

What are the chances?! I'm MSing a '74 CB550! And I too am concerned about alternator output, thus the fuel pump inquiry.

The trouble with about any new EFI motorcycle pump is that they're in-tank pumps. So much for keeping the tank intact!

Skiericski wrote:

bdjuju wrote: In my case the victim is a Honda CB550 - way low in the alternator output department. Maybe I'll just keep the headlight off?

What are the chances?! I'm MSing a '74 CB550! And I too am concerned about alternator output, thus the fuel pump inquiry.

The trouble with about any new EFI motorcycle pump is that they're in-tank pumps. So much for keeping the tank intact!

Wouldn't you know it, I also have a 74 CB 550 I've been eyeing up for a future megasquirt project ;-)

You're definately right, the output from these old honda 4s is not spectacular at all. However, my plan was to move from standard incandescent bulbs to LEDs for everything asside from the headlight. While you're only dealing with about 7watts for each low filament, with three lights on, thats 21watts, with the brakes on thats 40watts+, now have the brakes on, turn signals on, and you could probably see 80watts which could be reduced to under 10 with LEDs. This isn't counting gauge lights, dash lights, etc. I think there is plenty of savings to be found here to make it work.

Holy smokes.. So let me get this straight - there's 3 of us trying to 'Squirt SOHC Honda's? Too cool...somebody start a blog or something.

While I have the mic, either of you settle on throttlebodies yet? So far the best thing I can come up with are 38mm's off a GSXR600 - I think that'll be way to friggin big for good throttle response, but its the best I can come up with at this point. Only things I see with smaller TB's are Guzzi 750's or Suzi Burgman scooters. Not a lot of those around, and neither are I-4's, so its a PITA right off the bat. We shall see...