dhadley help pls on 1986 140 evinrude

[Dhadley]

Re: dhadley help pls on 1986 140 evinrude

There's a couple of things that can happen with the spark under compression compared to not under compression. But you say it starts right up if you squirt fuel in so we assume the ignition is OK and it's turning fast enough. If it wasn't, it wouldn't start when you squirted fuel in.

Just to start with the basics, let's try new plugs on a cold start. I'm not sure that will do anything but we need to know. If that doesn't change anything we'll get back to the priming issue.

 

[okam]

Re: dhadley help pls on 1986 140 evinrude

thanks, just gor back from work on my to get new plugs. I'll post back tommorrow. I also put fresh fuel i:e 6 gallon tank. I did have stabilizer in the floor tank but just tring to eliminate anything. Thanks for the follow upsd

 

[reeldutch]

Re: dhadley help pls on 1986 140 evinrude

i totaly agree with you dhadley,

but just to make shure there is enough juice at the plugs a simple test will tell you.

i agree that it might not get enough fuel trough the primer.
because it fires up when squirting extra fuel in there to get the gasoline/air mixture combusted.
and with the other carb he didnt have a problem.
with the engine cranking and 8seconds pre prime there should be a good amount of fuel comming out.
and he verified there is fuel comming out.
and it will idle fine when warm.

puzzles my mind

 

[Dhadley]

Re: dhadley help pls on 1986 140 evinrude

Don't worry RD, there are a couple of directions this may go but we have to verify the basics. There are a couple of really odd things that can happen but there's no sense going there until we've eliminated the basics.

 

[okam]

Re: dhadley help pls on 1986 140 evinrude

Put new plugs in set at .040, Pumped bulb, did a 8 count on primer, pumped bulb again and another 8 count , turned key with primer on motor started right away. Got motor to operating temp and checked plugs. #4 is clean I think its a head gasket. Checked compression 124# on all four. This was run with new fuel seperate from belly tank. I'll order new head gaskets unless I,m missing something.:$

 

[Dhadley]

Re: dhadley help pls on 1986 140 evinrude

If #4 is clean it could indeed be a leaking head gasket washing the fuel. You should see water droplets on the plug.

Or it could be no fire. In that case you should be able to shake some fuel from the plug.

Or it could be no fuel to #4. If it has spark but doesn't run on #4 then it's most likely that.

Or it could be a bad plug. You said it ran fine once it started with the old plugs. Was it running on all 4 before or just on 3 like it is now?

 

[okam]

Re: dhadley help pls on 1986 140 evinrude

dhadley, the first set of plugs had not been dedicated to 1 specfic cyl. The fresh ones have been. I fired it up after the last post and the water pressure gauge seem high for idle led me to believe the head gasket has a problem. Also saw unburned fuel in barrel after it warmed up. I've ordered new head gaskets should have them by monday next week. Will pull both head in the next couple of days and post back. Thanks again for following up on this. Sometimes the problem is not as it appears.d

 

[okam]

Re: dhadley help pls on 1986 140 evinrude

OK, finally got head gasket replaced. Still same hard start problem. After it warms up it will idle for 3-4 minutes then seems to run out of fuel, because if I bump the primer it will run again for the same cycle. I have #30 idle jets I,m going to try istead of the #33 that came with those carbs. I'll post back.

 

[okam]

Re: dhadley help pls on 1986 140 evinrude

Changed idle jets to #30s just smoke more, started cold just the same, and had same idle problem. Does any one know what the fuel pressure be after the VRO?

 

[reeldutch]

Re: dhadley help pls on 1986 140 evinrude

im thinking you might have a fuel restriction.

fuel pressure between the carb and vro pump depending on rpm should be never less then 4.5 psi and around 6 or more at higher rpm ranges.

if your fuel pressure is good than its not you fuel system.

if that doesnt check out ok do a vacuum test.

place a vacuum gauge before the fuel pump.
you should have a vacuum of about 2.5 Hg.

also place a 8" clear fuel hose before the vacuum gauge.
if you see a lot of bubbles and you have high vacuum then you have a fuel restriction.

if you see a lot of bubbles and no vacuum than you have a air leak in the system.

if you have good vacuum and no bubbles but your fuel pressure is low , then check out the fuel pump.

i think this could help you.

reeldutch

 

[okam]

Re: dhadley help pls on 1986 140 evinrude

RC, I put pressure gauge on outlet side of pump to carbs and started motor warm. I pumped the bulb to see if the gauge would rise and it went to 10psi on 2 squeezes as the motor ran dropped down to 1-1.5 psi at idle. Motor has a slight surge at idle then fades out to almost stall, I beleive i'm losing cyls then stall. If I hit primer motor kicks up on all four cyl. for another cycle. he top right carb, top cyl if I put several fingers slightly over the carb it does the same as hitting the prime button. The carbs were just rebuilt. I pulled the carb off and checked float level, OK. Srayed fuel mixture on gasket areas no differance unless enter top carb. I'm thinking the fuel pump might be out. Would this explain the surging?

 

[reeldutch]

Re: dhadley help pls on 1986 140 evinrude

yes you dont have enough fuel pressure.

it could be the pump or the fuel system before the pump.

you dont have enough fuel presure that means no
t enough fuel to the carbs.

why?

- bad fuel pump
- bad pulse
- air leak in fuel system (bubbles and no va
uum in fuel system)
- Fuel system clogged (bubbles in fuel system and high vacuum)

this means:

could be any thing in the fuel system. from thr tank vent to the engine fuel fitting.

you will need the vacuum gauge and the clear fuel hose to make it easyer to pinpoint the problem.


good luck

i think you wil find it soon

 

[okam]

Re: dhadley help pls on 1986 140 evinrude

RC, is there a way to test the pulse for the fuel pump, and what would be a range for the gauge. I'm assuming itt would be vaccum.

 

[Dhadley]

Re: dhadley help pls on 1986 140 evinrude

The pump runs on pulses. Pressure, vacuum, pressure, vacuum etc.

Did you solve the problem of the motor not running on #4?