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.
Common question.
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.
5-5-1-6
Ported 1300 engines baseline EFI settings.
7-7-7-7
Ported 1390 engines baseline settings.
11-11-11-7
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.
Thanks, Ross
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.
Common question.
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.
5-5-1-6
Ported 1300 engines baseline EFI settings.
7-7-7-7
Ported 1390 engines baseline settings.
11-11-11-7
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.
Thanks, Ross
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