40 hp fuel pump questions

[karlow1]

In my saga on how to fix my 1990 Johnson, my latest effort revolves around changing the fuel pump. I had previously noted that my VRO-2 pump was failing. I converted the boat to a pre-mix boat with some success. The clouds of smoke at idle is now gone, but the pump was still ticking way too much. I installed a std. non VRO pump. Today, I reinstalled, correctly this time! First question, in have read that I should replace the std pulse nipple that is used with the VRO pump. I pulled it. it seems to be a antibackfiring blocking valve. My question is is it defective. It is completely free flowing in both directions. It does not seem to do anything! I expected it might be a check valve, or it would block if you blew on it hard in one direction. No nope nothing.
I checked the replacement (new to me) pump. At idle it produces about 2 psig.
It will pump about 2 oz of fuel in about 20 sec at idle. My question is doe that seem OK? I had planed on just replacing the pulse nipple, but it is not a std NPT thread. Do I need to replace it? So far thing seem OK, but It has only been run on the hose.

KP

 

[tashasdaddy]

Re: 40 hp fuel pump questions

did you use a 2 line or a 3 line fuel pump?

 

[karlow1]

Re: 40 hp fuel pump questions

It's a three line pump.
I thinks it came on a 55 hp about 1980 vintage.
It's an Ebay thing.

 

[tashasdaddy]

Re: 40 hp fuel pump questions

it should work. i usually change mine out to the 2 line pump and use the bypass mount on the block.

 

[karlow1]

Re: 40 hp fuel pump questions

I'm sure it will work, my question is does the pressure at idle sound OK?

 

[karlow1]

Re: 40 hp low speed/idle problem

Re: 40 hp low speed/idle problem

Up-date!
I made to the lake on Sat.
The engine did not want to remain running in the morning.
It would start OK, and run for a few cycles and die.
I did this maybe 6 or 8 times. Some time it would run for a few sec.
It seems to get a little worse as it warmed up a little.
I cranked up the idle, and It keep running, then it speed up.
It may have been running on one cylinder. I reduced the idle to something around 900RPM. I trolled for a bit with no problems. It ran OK near full throttle.
It almost seemed OK. It has a miss or something at part throttle, at around 5 knts maybe 1500RPM. It does it sometimes at troll speeds as well. I did some carb adjustments at troll speeds. It seemed happy. It trolled along fine for about an hour W/O stalling. It's too fast for trout, and a little slow for stripe bass. It's maybe 1.8knts at 900RPM? the tack is a bit wacky at low speeds What do you think? The carbs has been cleaned 3 or four times. I just replaced the wires. The plugs are set to 0.30. The replacement pump seems OK. It seems rich, but seems to be happy at that setting. The carbs have been sinked. The compression is great, What am I missing? My current plan is to change nothing before the next trip to the lake to see if it will start right up.
What's next?
I did catch three trout size stripers... Sad.
it was a great day on the water.

KP

 

[karlow1]

Re: 40 hp fuel pump questions

No comments?
I'm thinking a little increase in timing, or a little increase in float level.

What say you?