07-10-2008, 08:57 AM #1
When do I need an EFI fuel controller?
Making this post in reference to the most asked question here in yamaha 2 stroke section.
Fuel controllers add fuel to the engine and do nothing else.
The standard R&D and Riva controllers are the same thing.
The R&D powershot fuel controller has the adjustable LED lights and is a prettier version of the same thing, which i will go over later in this post.
The stock fuel circuit at WOT is very rich, and needs no extra fuel on a non ported engine, even with a 3 degree keyway and machined cylinder head.
The midrange circuit 4000-5500 is lean and that is the circuit that needs more fuel.
The number one pot on the standard controller is for the main or cruising circuit.
The number 2 pot acts as an accellerator pump when the throttle is stabbed.
The number 3 pot is for the WOT circuit.
The number 4 pot is the rpm at which it crosses over from the main circuit, to the WOT circuit.
The pot positions are read as you would read the hand of a clock, from 1 being the leanest, which is on the stock fuel curve, to 11 being the richest.
I have a Riva flame arrestor and vf3 reeds, d plate and free flow tube on my non ported ski. Do i need a fuel controller?
NO, you dont need one, but the installation of one will enhance your midrange performance, but do nothing for your top speed, rpms.
I ran my sonic boom throttle bodies on a bone stock 1300 for 6 months without a fuel controller and it did fine, but was a touch lean in the midrange circuit.
A fuel controller in not necessary until the compression, and or, 3 or more degree timing keyway is installed, which creates higher cylinder temps.
Non ported 1300 engines baseline EFI settings.
Ported 1300 engines baseline EFI settings.
Ported 1390 engines baseline settings.
Baseline are starting numbers that usually are on the rich side, but should be very close to perfect from my experience.
Remember your EFI ski has a barometric pressure and temp sensor which automatically changes your fuel curve with changes in the weather, so changing your EFI settings because the weather is 30 degrees cooler should not be necessary. The ECM will do that for you automatically.
Many modifications work well together as a kit, but poor by themselves.
I suggest saving $ until the modifications can all be installed as a package for maximum results and minimum headaches.
Rich (WFO) and i have talked about this, and he will add to this post from his vast experience with efi skis also, in an attempt to clear up some of the muddy information that is out there.
Last edited by rossnemo; 07-10-2008 at 09:00 AM.
07-10-2008, 09:16 AM #2
Ross you are the man
07-10-2008, 12:32 PM #3
- Join Date
- Feb 2007
- Cape Town, South Africa
07-10-2008, 12:34 PM #4
07-10-2008, 06:40 PM #5
Great post. This will help alot of people including myself.
07-10-2008, 09:30 PM #6
07-10-2008, 09:45 PM #7
07-10-2008, 10:29 PM #8
07-10-2008, 11:34 PM #9
POWERSHOT FUEL ADDITION AMOUNT SETTINGS
GREEN VALUE * * * * * * * * 4
YELLOW VALUE * * * * * * * * 5.5
RED VALUE * * * * * * * * 3
POWERSHOT CROSSOVER POSITION SETTINGS
GREEN/BLUE VALUE * * * * * * * * 0
YELLOW/BLUE * * * * * * * * 4
RED/BLUE VALUE * * * * * * * * 4
This the R&D chart for what they call both a stage one and a stage 2 gp1300r.
The fuel addition portion is the same as the original controller, except it is more accurate in its adjustment as it uses led lights on a 1-9 scale, and is programmable in .5 increments. So instead of having only a 1-2 or 3 as a setting, you can use a 1.5- 2.5- 3.5 etc. Its a little more accurate and much easier to read.
The crossover portion is different. You simply have a crossover that picks a rpm that turns on each of the 3 fuel addition settings.
Using the 0 on the green led would turn on the fuel to that circuit immediately upon startup, or by raising the setting you could delay the addition of fuel to the rpm of your choice.
I do not know how the correlation chart would be from the number on the crossover setting to the rpm it would activate at.
The only setting on the chart that is off is the number 3 fuel addition setting which they reccomend at a 3.
This is very rich for a non ported 1300. I ran my egt system to monitor temps and ended up using the lowest setting, which they would call a zero for the red WOT led.
My fuel addition settings i use on my non ported ski with all the bolt ons are
My crossovers are set as they reccomend on the chart, and i really havent experimented with them much.
On my egt gauge i had a 10-15 degree drop for every half point i dropped the red led. From their reccomended 3, to the zero i ended up at i went from 1010 degrees at the rich 3 setting, to 1065 degrees at the zero setting.
I raised the midrange settings to cool the burn a little. The non ported 1300 runs very hot at 4000-4500, around 1220 degrees, and that was on their reccomended 4 setting, so a little extra fuel there took 20-30 degrees off it, and it has a killer holeshot for a non ported 1300.
I have not used this on a ported 1300 so i have no info on that. Im sure the fuel addition settings would be higher, especially the red led, to maybe a 5 or 6.
The best thing about this controller is, according to glen at R&D. It can be reprogrammed to add even more fuel if necessary with different software!
Hope this helps everyone.
07-11-2008, 02:19 AM #10
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