You are doing a great job of presenting this information. Thank you for the effort.

Thanks for sharing this information. You explain everything in great detail and it definately helped with my understanding of how the system works. Thank You!

Appreciate all your information I need to learn all I can. Thank you again.

Thanks. CHEERS from AUSTRALIA.

Great video. The provision for the injectors above the throttle plates are there for vehicles that are running dual injectors and dual barrel valves, high volume. The second valve will open at WOT or about 3/4 throttle. Some vehicles will run larger injectors, however it's hard to get them to idle with large injectors so they go to a dual setup. The four whole injectors you were talking about are for higher volume or bigger cubic inch motors, normally different types of fuel. You are absolutely right by saying it creates a vacuum leak, their purposely trying to do it. Adjusting the throttle blades would also work but they would need to be about a quarter ways open. If you were to move your injectors to the top of the throttle blades and not below for a single setup such as yours it would not run properly. Due to the fact they would push fuel on top of your closed throttle blades. Thank you for taking the time to make these videos. I wish they had them when I started out. Just happened to stumble across them when trying to explain this to a friend of mine.

Good detail information Mts

great video I have been running mfi for years . would have been very helpful in the beginning . It was a learning curve for sure once sorted out it is pretty simple . Thanks for contributing to the sport

Another great,informative video thank you

Great stuff!

Excellent information thank you

I am building an MFI Harley & came across your videos when I was researching secondary valves, & spring pressures between the bypass valves and secondary, & all that goes in with designing a system. And have to say that that these videos were really informative & very helpful to me. As you know, there isn't a ton of information that can be found at the same source, its kinda all scattered around, & you have to hunt the info down. Anyway, I wanted to let you no, that I will be coming back to visit these vids, when it comes time to assemble the system. Also I will be building one of those digital leak down testers to test the valves, to really dial them in, Im ordering the parts now, so I have them here to build it. I even found them orifices at McMaster & Carr...

Good info,we run a Kinsler set up on our landspeed roadster, it’s a challenge for sure,some say with a scoop don’t run high speed then others say to run it. It’s the great whit dyno and this year we will be running the high speed,just a challenge to figure when to bring it on as far as RPM which turns into which spring ect.We will use a pill in the can so not to lean it to much

Awesome thanks

Thanks for taking the time to explain all this cool stuff! Aren't the standard "average" quick disconnect air fittings 1/4" NPT?

I think your video's are GREAT! I am new to MFI, I run a SBC (429) hi helix 6-71 on methanol. Hat injection, 12GPM pump, (8) hat injectors .046. currently running a 5lb idle check and 150lb high speed check, main pill is at 105. Cant seem to get the idle down below 24/2500. .006 on butterfly's, 80% leak-down on K valve. Air bleeds on injector base, could my idle check be to low? Please keep these videos coming. Thank you

Wouldn't the nozzles with the 4 air bleeds be creating a basic vacuum leak, or fast idle?

Late to the party, but what would happen if you spray the fuel back up towards the throttle blades? Would it give the fuel more time to vaporize?

I do not believe the AN threads are exactly the same as pipe threads. close but not the same.

To test secondaries or High Speeds, us a single gauge only.......K.I.S.S. You'll see immediately at what pressure the poppet or diaphragm opens. Also, submerge the secondary (with a pigtail) in a bucket of water for the most accurate result of leak.