Evinrude 1993 150 hp stalling issue.

[stalker170]

I have been dealing with this for a while and cannot find the issue. Motor runs perfect when you start it up, runs great all thru the power ban and at WOT. But after I get to my fishing hole and try to move, the motor stalls when I put it in gear. All I need to do is keep pushing in on the key to give it choke and I am all set. I would really like to get this fixed, because it can be a real pain when loading the boat or taking off after warm up. This is what I done so far:
1. Replaced all fuel lines and primer bulb.
2. Tried both onboard fuel tanks. (Just thought if anti siphon was bad in one, switching tanks would cure it)
3. Changed Trigger.
4. Change power pack.
5. Rebuilt all six carburetors.
6. Changed VOR pump.
7. Check reed valves, all seem perfect.
8. Did compression test, one side a little low so I replaced head gasket o rings, Great compression now, cylinder walls look perfect.
9. Changed temps switches.
10 Changed thermostats.
11. Replaced fuel switching valve.
12. Replaced spark plugs.
13. Replaced spark plug wire with high resistance ones.
14. Sprayed starting fluid around intake plate to see if the motor has vac leak
15. Checked vents in the tanks.
16. Timing is right on per the manual, tried advancing a little, no help.

Like said, not disabling by no means, just a major pain. I fish 15 tournaments a year and if I decided to upgrade boats, I need to get this fixed before I sell to anyone.

I have researched these forums, some posters are saying something about heat under the cowlings and vaporizing the gas causing air bubbles. I have had this boat and motor a long time. Just started doing this in the last two years. Same cowling and same motor, so if it is vaporizing, why did it just start doing it in the last two years. Also I read about increasing idle jets. Mine are fixed so I would have to go up in size. My tops fixed jets are 28's, bottom ones on the face of the carbs are 40's.

Andy help would be great.

Mark

 

[flyingscott]

What is your idle rpm in gear

 

[stalker170]

About 750 to 800 in neutral after warm up and drops off quick start.

 

[boobie]

If pushing in the choke helps, your carb is running to lean. If you can find a dlr who stocks a lot of jets you can try re-jetting it but it's a matter of trail and error doing this. Been there.

 

[stalker170]

Bobbie, Thanks for the help. I have read this before about re-jetting. Like I said, the tops are 28 and the bottom are 40, that is looking at the carburetor face, left side, all are fixed jets. Do I increase both thru trial and error, or one is the idle jet? If so what one? Top or bottom?

Mark

 

[stalker170]

Anyone else got any ideas. Seems like I read about this being a problem but not seeing a remedy.

 

[boobie]

The remedy is getting the right jetting done.

 

[garx66]

I have similar problem, my idle system has an adjustable screw which if I'm not mistaken changes the amount of air, is there a removable jet beneath that screw?

 

[boobie]

Depends on the year. Some regulated air and different years fuel.

 

[James R]

A couple of points of interest. The idle at neutral seems a bit low. That RPM should be with the prop engaged. Is it possible that you are dropping one or more cylinders when she's warm which may be an ignition problem. If you are over oiling these motors dont like it.

 

[stalker170]

Thanks to all of you for giving me ideas. Bobbie, I tried a trick that a guy told me to see if I could see improvement. He said take a baggie tie and strip the paper of the out side. put the wire in the end of the jet, (reducing the size of the hole) Then he said you should see improvement by reducing the air. I did try this but no difference. This boat runs perfect from start up to WOT when you take it off the trailer. Even running up lake you can pull the throttle back and it runs great when going slow speed. It all happens after you shut it down for a bit then fire it back up. Put it in gear and it stalls unless you hit the choke twice to increase RPM

James, I have replaced everything except the stator. Wires, coils, Power pack and trigger. I did try a different power pack Saturday, but no difference.

I could be over oiling? I did have the VRO pumped replace, but it was doing this before the pump issue. I have delt with this for about four years. Like I said, boat runs perfect except for this small issue. Love to fix it. How do I know I am over oiling??

 

[flyingscott]

A couple of points of interest. The idle at neutral seems a bit low. That RPM should be with the prop engaged. Is it possible that you are dropping one or more cylinders when she's warm which may be an ignition problem. If you are over oiling these motors dont like it.

AGREE You need to double check the idle set it while in gear and warm find those specs.

 

[stalker170]

Flyingscott So should it be at 1200 RPM in neutral? What also happens after warm up even if you don't put it in gear you see/hear a miss or a sputter then it also will quit unless you hit the choke. I even tried to advance the timing a bit at warm idle, no help. Let me know the RPM I should be at and I will set it.

 

[flyingscott]

If it's only been doing this for 2 years and was good before that probably not a jetting problem. 1200 rpm on muffs is okay that will drop in the water. Find out if you have. Were those automotive spark plug wires you put on. Have you done a spark test to make sure it's jumping 7/16" of an inch. I don't know if your motor has one look and see if you have shift interrupt switch. Also are you positive the carbs are clean and what kind of clamps did you use on the VRO hoses.

 

[stalker170]

Carbs were rebuilt by me and then I also had the local shop check everyone that I did to make sure I didn't miss anything. When I put the coils on I put the resister type for that motor (OEM) because I read that that could cause the issue. (No Change) Have not done the jump spark test, I will do that. If not jumping 7/16", then Stator?? I have tried all new coils, wires, plugs and two different power packs. (no change). VRO clamps are the ones that came off originally, the squeeze type. Should I put regular clamps on all the VRO hoses?

 

[flyingscott]

I put oetiker clamps on my new VRO pump hoses. You really should not reuse the old clamps as they were not great new and get worse over time. They need to be replaced at a minimum with new clamps and don't use zip ties.