1989 evinrude 40hp fuel issue

[remingtonboy]

Hi guys I recently bought an 89 evinrude 40hp that didn't run well so I'm trying to bring her back to life. I replaced the spark plugs. I put new fuel/oil in the tank, new fuel line/primer to the motor, new fuel pump last night. But it still will only run when I hold the electric choke button in. As soon as a let off of it. It runs out of fuel and dies. Would carb kits be my next step or am I forgetting something? These fuel pumps run from pressure/vacuum correct? So the pressure comes from the tank, where does the vacuum come from? Could I be losing that?

 

[racerone]

Having to push the primer in to keep it running proves 2 things.-----Your fuel pump is working !-----And the fuel pump pushes fuel through the primer and directly into the engine.----This fuel bypasses the carburetors !!-----So you have carburetor issues.-----The fuel pump works with a + pressure pulse from the engine crankcase.----And a slight negative pulse as well.--------So it is time to have a look in the carburetors.----Pay particular attention to the high speed jet / orifice plug that is screwed into the bottom of the carburetor bowl.

 

[remingtonboy]

Ok great advice! Thank you. I guess I'll order kits and dig into the carbs.

 

[racerone]

I would do a compression test before spending any coins on it.----There may well be a reason for it being on the market / for sale.

 

[remingtonboy]

I will do that tonight. What should the compression be on those cylinders?

 

[racerone]

Post your numbers.----Comments will follow.----What do you mean when you say " new fuel / oil in the tank " and new fuel pump.----Is that 50:1 mix ?-----Did you install a new VRO pump or other ?---VRO pumps are pricy and no need to replace one on a hunch.

 

[spybot]

I would do a compression test before spending any coins on it.----There may well be a reason for it being on the market / for sale.

This is a MUST do on any new to you engine. I and others have learned from this.
I cant stress enough DO A COMPRESSION TEST before spending any cash on the motor.

 

[remingtonboy]

Post your numbers.----Comments will follow.----What do you mean when you say " new fuel / oil in the tank " and new fuel pump.----Is that 50:1 mix ?-----Did you install a new VRO pump or other ?---VRO pumps are pricy and no need to replace one on a hunch.

I mean I dumped the old gas out and mixed new gas at 50:1 and I did not install a vro pump. I don't believe it has one as it is a mix motor with no oil reservoir. And i replaced the fuel pump because i thought it might be weak.

 

[racerone]

A new diaphragm at $5.00 or so fixes most fuel pumps.----Not sure why folks run out and buy new pumps.

 

[remingtonboy]

Compression test yields 115lbs on both cylinders

 

[oldboat1]

Get the carb kits (MO). Do one at a time, so you have one for reference, and good to have a parts diagram in front of you.

Disassemble and soak all metal in solvent strong enough to cut through fuel varnish (leave linkages in place). I leave the jets in place, and clean with a piece of soft wire or monofilament. Finish with carb spray.

 

[remingtonboy]

Got it I'll start on that tomorrow night. Thanks!