Ok here we go.

Hit the dunes a few weeks ago. New I had low fuel pump pressure on one FL350. Tried putting jet into return to tank line. Did not work. Burn the piston.

I do a top end rebuild with good used parts I had. It has 150 pounds on the bench test. Leak down test holds 7lbs for an hour now. Maybe a hair size in drop in hour. Fuel flow rate is little less than 2 oz per 10 seconds. I tried new fuel filter. I tried pick up line in derect gas bypassing petcock. I tried 3 pumps and all the same. All these test on the bench. New pulse and fuel lines reinforced hose. Also tested with new Honda T valve and bypassing T to derect pump all the same. When I crank over Engine I have enough pulse to blow shavings and dust around on my bench. So I do have something but is that enough?

I have two engines. Both doing same thing. I have not leak tested number two yet.

My question is should I look at reeds now? I have another machine that passes the 4 oz flow test. Also is their a way to test pulse pressure?

Stumped.

Well you clearly know how much flow you need so I don't need to waste any time on that.
Your pressure test is good also.
From what I read there you by passed the fuel petcock by putting a hose direct into fuel tank from pump.
So I am assuming you put the pressure line from pump direct into a measuring cup and got 2 oz on all three pumps. Right now I am thinking the pulse line for the pump is not tight or all three pumps are no good. That's all I can think of right now.
As for testing your pulse line -- yes you can check it. You need a vacuum/pressure gauge. You should be able to get one of those at an auto store. With it hooked up to pulse line you should get 7 inch vacuum and 5 psi pressure as the Engine is being turned over. That's what I get on my machine.

If you run it with that flow rate your gona blow another hole in a piston.

Just the way you are explaining it there and based on what I see in that picture I would say all three pumps no good.

You said you knew you had low flow on one of your oddys. So I assume you have more than one and the other one runs ok. I would pull the pump from the one good oddy and check the flow with your rebuild Engine, but FIRST check the flow on the good oddy BEFORE you take the pump off. That way you know it is good to start with.

I did test pump from other machine. Also bought and tested that mukuni round pump you see. I also used 3/16 fuel line on pulse line. So I know it's tight. Also tried other shorter lines. I get 2oz with petcock or without petcock. I just tested another new Oem Honda tee. Even less when using T.

Would reeds effect the flow? Going to test pulse pressure now.

Yes I would believe reeds do make a difference.
Those pumps would need pressure and vacuum.
I just find it hard to believe your reeds are that bad.
I also find it hard to believe 3 pumps are no good but that's all I can think of right now as you have done everything I would have done.

Just for a test put each of those "bad" pumps on your good machine and test the flow.
What do you get ??
If they work then you know for sure it is something with the bench Engine.

I just test pulse pressure. My needle bounce all around like crazy. Up to 5lbs. Then when stop cranking it stop at 2 to 3 pounds a leaked to 0 fast.

I will do the pumps swap out tomorrow.

Thanks.

Well then your pulse is good and so are your reeds then.
You got 3 shitty pumps I bet. That will show on the other Engine tomorrow.

Thanks again. I will look into the pumps more.

George

that's what it will be I bet money

Also noticed your engines are still air cooled.
Hope your running high octane fuel.

I run local super gasoline and yamalube 32.1.

I put the new mukuni round pump on my other machine. I got 2oz again. But I tested the other machine flow rate and also got 2oz. I also tested flow rate back to tank at about 1oz. This machine past the flow test last summer. So basically all the pumps I have are now doing the same thing. One being brand new. The China pump is a giving. But the new pump concerns me.

The two square pumps I was running I notice are the China knockoffs. The mukuni round pump I just bought is original Mukuni. Dual outlit I put 2 into 1.

I just ordered 2 mukuni pumps original square. If these fail to pump more something else is going on.

Thanks. I probably read all your post on fuel flow. Tried everything before I made a post I hope its the pump. Pretty much has to be at this point.

When you say high octane? What number is high?

My money is still on crap pumps because you tried on several engines and getting the same flow rate.

High Octane -- AVGAS or a mix or Avgas/pump gas.
Just my opinion.

I wouldn't trust a shitty Chinese made fuel pump. If you still have the stock fuel pumps, pick up a Winderosa rebuild kit and rebuild the stock pump. I have tried three of them and have had great results.

Rand

Hey Rand has anyone done a COMPLETE write up on the rebuild of a fuel pump using the Winderosa kit ?? I thought I read somewhere here where a member had trouble rebuilding with this kit, not because it is not good but because it was difficult or the instructions were no good. Maybe I am wrong. I don't remember the thread.

Here it is: viewtopic.php?f=1&t=16403&hilit=winderosa+kit
Oh yeah now I remember -- it was you

Man that kit was a pain in the ass to figure out! I did one just recently for Mcali2. That one went easy.

If I rebuild another one, Ill have to do a how to.

Rand

That's what I was implying.
No one has actually done a good picture and info thread on doing this.
I have several pumps here and think one day I may try one kit.

I could bring you my 5 spare fuel pumps to try, I'm sure one of them must work
Bob

Funny you mention that. I found old stalk fl250 pump I had. Unknown condition. I tried it and got again 2oz. Brain thinking I notice my clear hose I was testing with is slightly larger tube. Just to be sure I dropped down to smaller 3/16 hose throughout. No change with 3 pumps. All 2oz.

2nd new pump will be here today.

F this F that. Freaking pist. New mukuni square pump and guess what. Same 2oz.

Would not have a carb and pipe on effect my results? 3 engines 6 pumps all pumping 2oz. You got to be freaking kidding me? Who came up with 4.5oz?

Idk. Would starting Engine and have good prime on it matter? I am baffled.

The test are on the bench. Both with new T valve and without T Valve. Gonna go test other Engine with new pump. Freaking freak.