Logo
FULL SITE MENU

1987 Evinrude 150, odd problem

A

AJV1967

New member
Hello, I’ve searched and searched for a clue to my problem on here for a while an coming up
short and boating season is close. So the problem is with a 1987 E150STLCU with a jet pump on a 1987 Duracraft with built in fuel tank under seats.

The problem is this,
While running 10-15 miles up river I haven’t had a problem, but coming down river with less fuel the motor will act like it’s starving/choking. If I catch it soon enough and kick it into neutral and feather the throttle a bit I can keep it running. If I don’t catch it in time it will completely die, after its completely killed starting back up is usually not a problem. It will do this 3-7 times or until I get back the ramp and on the trailer. I’ve tried to slowly as well as quickly squeezing the primer bulb once it starts doing it and that changes nothing, it will still cut out and die. Could the diaphragm fuel pump be bad? But what would explain me not having any problems going up river with a full tank?

What I’ve done to troubleshoot is this,
With motor idling in water on boat ramp on trailer, remove cowl and spray fuel lines with carburetor cleaner to see if there’s a crack in fuel lines sucking air which if so the motor would either bog out or rev up, but neither happened.
Replaced plugs, would have to look at which ones I used cause it’s slipped my mind.
Drained fuel tank and let air out before refilling.
Replaced fuel primer bulb and filter.

Other questions I have,
What is the proper water pump replacement number?
What plugs are recommended?
Best way to “winterize” this motor?

Thank you, willing to try any ideas but may be a couple days before attempts are made. Super busy with work, we all know that feeling!
 
Little update after more researching,
Previous owner must have removed the VRO system and converted to fuel pump. I’ve read the 1983 motors had 2 fuel pumps, mine is a 1987 and was only rigged with 1. What could or would be the reason for them using one over two pumps? How would I properly add another one and is it necessary? If 2 are needed to be correct, could anyone provide me proper part numbers for both pumps unless they are the same. I appreciate it, thanks again
 
AJ, You state "The problem is this, While running 10-15 miles up river I haven’t had a problem, but coming down river with less fuel the motor will act like it’s starving/choking." You also state that you have a built in fuel tank (singular) under seats (Plural) .

I assume you have just the one fuel tank...... Your explanation of the problem describes a fuel pickup tube within the tank that has a hole, a rusted area broken out, a break, whatever, in it that when the tank is full, there is no flaw in the fuel flow.

However as the fuel is used and the fuel level drops to the point where that flaw is exposed... the fuel pump will draw air. At that point, in pumping the fuel primer bulb, the primer bulb would also draw air.
 
Last edited:
Joereeves,

Thank you for your suggestion on the fuel pickup tube, will definitely inspect it. You are correct on the fuel tank, it’s 20gals and built in under the two main seats. Do you have any input regarding my motor only having one fuel pump installed instead of two? From what I’ve read, it’s “normal” for there to be two installed after removing the vro system.

Thank you again!
 
Depends on what type pump was used to replace the VRO..if like below it is 2 pumps sandwiched together
images
 
Faztbullet,

It is similar to what you have pictured except there’s only one. I included a picture below. I have yet to find one with the fitting in the rear of the pump.
 
Last edited:
AJV1967 said:
Joereeves, Thank you for your suggestion on the fuel pickup tube, will definitely inspect it. You are correct on the fuel tank, it’s 20gals and built in under the two main seats. Do you have any input regarding my motor only having one fuel pump installed instead of two? From what I’ve read, it’s “normal” for there to be two installed after removing the vro system. Thank you again!
Click to expand...

The engine running normally for 10-15 miles traveling up-river indicates the single fuel pump is doing its job... impossible for it to be selective on the tide flow or fuel level. If possible to install dual pumps (mounting holes), it wouldn't hurt... but... if not easily done, I wouldn't be concerned about running with the single pump.
 
AJV1967 said:
Joereeves; Thank you for your suggestion on the fuel pickup tube, will definitely inspect it. You are correct on the fuel tank, it’s 20gals and built in under the two main seats. Do you have any input regarding my motor only having one fuel pump installed instead of two? From what I’ve read, it’s “normal” for there to be two installed after removing the vro system. Thank you again!
Click to expand...

The engine running normally for 10-15 miles traveling up-river indicates the single fuel pump is doing its job... impossible for it to be selective on the tide flow or fuel level. If possible to install dual pumps (mounting holes), it wouldn't hurt... but... if not easily done, I wouldn't be concerned about running with the single pump.
 
Joereeves,

Well I thought I knew how to include pictures but it appears not so much, gonna have to figure that out. Would the dual fuel pump be better?
 
An 87 block should have the provision for the 1983 model dual pumps.----Remove the pulse limiter if that is in there.----Remove plug for pulse fitting for the second pump.
 
racerone said:
An 87 block should have the provision for the 1983 model dual pumps.----Remove the pulse limiter if that is in there.----Remove plug for pulse fitting for the second pump.
Click to expand...

Could you explain to me where the pulse limiter would be and reason for removal?
 
The pulse limiter would be a FLOW FUSE for the VRO.-----About a 3/4" hex fitting and either black or blue plastic is part of it.------Not needed for conventional pumps !
 
racerone said:
The pulse limiter would be a FLOW FUSE for the VRO.-----About a 3/4" hex fitting and either black or blue plastic is part of it.------Not needed for conventional pumps !
Click to expand...

Where is this located at on the block? With removing the pulse limiter, would that be where I would place a barb fitting for the second fuel pump to pull “vacuum” from?
 
racerone said:
These pumps run on PRESSURE pulses and just a wee bit of vacuum from the crankcase !
Click to expand...

I will see if I can locate where pulse limiter is and determine if it’s still there or not. Correct me if I’m wrong. If it’s still there I need to remove it, install a barb fitting and plumb my second fuel pump off that. If it’s not there and there’s a plug in said port, I need to remove the plug and install a barb fitting and plumb my second pump off that.

I appreciate the help, learning more off each reply from you all!
 
AJV1967 said:
I will see if I can locate where pulse limiter is and determine if it’s still there or not. Correct me if I’m wrong. If it’s still there I need to remove it, install a barb fitting and plumb my second fuel pump off that. If it’s not there and there’s a plug in said port, I need to remove the plug and install a barb fitting and plumb my second pump off that. I appreciate the help, learning more off each reply from you all!
Click to expand...

AJ... The "Pulse Limiter" would be hard to miss... a metal and plastic combined item found in the pressure line running from the crankcase to the VRO pump, designed to either cut the pulse somewhat or possibly keep any flame within the crankcase from reaching that large cavity VRO pump (Who knows?) In either case, it is NOT needed or desired to be incorporated with the smaller fuel pumps which prefer the full pulse blast.
 
The pulse limiter closes when to much air / pressure develops in the crankcase.----Prevents the flimsy plastic VRO pump from exploding due too high internal pressures.----The conventional pumps are stronger / smaller surfaces and do not suffer the same.
 
joereeves said:
AJ... The "Pulse Limiter" would be hard to miss... a metal and plastic combined item found in the pressure line running from the crankcase to the VRO pump, designed to either cut the pulse somewhat or possibly keep any flame within the crankcase from reaching that large cavity VRO pump (Who knows?) In either case, it is NOT needed or desired to be incorporated with the smaller fuel pumps which prefer the full pulse blast.
Click to expand...

I am thinking this is the pulse limiter, is that correct?
48cb5170-7e94-4090-92b5-ba34ab97e2fa
https://www.crowleymarine.com/parts/15554.cfm

So ive found that piece and removed it. Now I’m replacing fuel lines from tank to motor and will see if it changes anything. Thank you
 
Last edited:
Back
Top