1980 Mercury 40hp turn over-no start problem

[terrybb]

Hope someone can help/advise me about my issue. Have a '80 Mercury 40 hp Thunderbolt. It's a 2 cyl./2 stroke with elect. start. I'll try to be brief. Boat & motor was given to me by my sister about 6 months ago. Boat itself needed some minor (mostly cosmetic) work. Motor was fine (per sis.). Over the last 5 months, worked on boat itself. Never tried to start motor during that time due to no battery, did periodically manually turn motor several times each to keep it freed up. Three weeks ago, boat finished, bought new battery, replaced old fuel (fresh fuel mixed 50:1) and cleaned tank. After about 15 minutes of trying to start motor, it finally started, ran a little rough at first(dog ears attached), but mellowed out. Worked throttle in forward & reverse, no problems noticed. Next day, put boat in water. Motor was a little hard to start, but started and idled okay. Under load and under way, motor performed amazingly well for something that hadn't been run in awhile! Have had in water twice. Problems that I have..after motor has been running awhile, it dies when in neutral at idle. Also, hard to start problem got worse. Now, motor turns over, but won't fire up. Have spark (at plugs, blue color). Pulled carb to inspect/clean, it looked alright, cleaned anyway. Fuel seems to be getting to carb. Any suggestions before I give up and take to mechanic?

 

[latin monkey]

Re: 1980 Mercury 40hp turn over-no start problem

try squeezing the primer bulb on the fuel line and see if it will stay running, if it does then get a fuel pump kit and rebuild the fuel pump, take carb apart and clean thoroughly

 

[roncoop75]

Re: 1980 Mercury 40hp turn over-no start problem

Have spark (at plugs, blue color).

Did you test that with a spark tester or just the plug?

As per suggestions here it should throw a crisp, bright, blue spark about 5/8" if I remember correctly. Seems like quite a distance, I didn't think mine would do it, but it did!

Only reason I ask is it seems like it's happening after warming up, it got worse over time and it runs at speed (when it ran) but dies at idle. Low speed stator going out? I could see a heat related electrical problem there.

 

[terrybb]

Re: 1980 Mercury 40hp turn over-no start problem

To answer roncoop75, did not check spark with tester, pulled plugs, reattached plug wires to plugs and grounded against engine, turned ignition key, saw spark, blue in color. As I am new to marine motors, what/where is low speed stator and, more specifics on possible heat related electrical problem(?)

To answer latinmonkey, carb has been pulled and cleaned, fuel seems to be getting to it. have not checked for fuel pump issue yet, not sure how to check it without pulling it off motor, any suggestions? As of now, still can't get motor to fire up & run. At times, while trying to start motor, it "acts" like it wants to fire up, but doesn't.

Just to let you guys know, I really appreciate your time & input!

 

[latin monkey]

Re: 1980 Mercury 40hp turn over-no start problem

does the primer bulb on the fuel hose stay hard after you squeeze it a few times?

 

[terrybb]

Re: 1980 Mercury 40hp turn over-no start problem

Sometimes, I was just out there messing around with it, was squeezing bulb to get fuel into fuel filter site bowl, took more than a few "squeezes" to fill it. Never really felt bulb got hard, also, heard something bouncing around in bulb.

 

[latin monkey]

Re: 1980 Mercury 40hp turn over-no start problem

i would suggest getting a new fuel hose and bulb and check tank fitting to make sure its tight, the fuel hose in tank may be clogged also so be sure to check it. this is relatively inexpensive and at least you can rule it out. if it doesn't help and primer bulb still doesn't stay hard i think you need a fuel pump kit. if you do get a kit, ask for the one with new check valves and pay close attention to the position of the old ones in the fuel pump so you can put the new ones in the same way and also get a new fuel filter while your at it. i think you are having a fuel problem but if i'm wrong at least you will have a good fuel system and like i said its relatively inexpensive. let us know how it goes

 

[terrybb]

Re: 1980 Mercury 40hp turn over-no start problem

Yeah, my overall thought is that I have a fuel related issue. It's just strange that motor was running fine (minus idle and hard-start problem) and now, won't fire up. This no-start problem started after we had been out on water, got home and I went to flush motor with fresh water, but couldn't get motor started. The carb on this motor is a side bowl type and is fairly simple in design. There's not many parts to it, we pulled it off motor to inspect/clean, even bought a carb repair kit. The gas tank is 6 gallon O.E. metal from Mercury. Emptied out all remaining fuel from last time on the water, checked tank for anything that wasn't supposed to be in there, it was all good, nice & clean. Filled back up with fresh fuel (50:1). Fuel seems to be entering motor through carb, pulled plugs and they were a little wet with fuel/oil. Even shot a little WD40 intake carb to see if it would fire off motor, nothing though...May go ahead and get a fuel pump kit, 2 new spark plugs (they are surface gap type), and fuel line with new bulb. Just can't afford much, unemployed right now, economy ain't great here in Florida.

 

[dac011]

Re: 1980 Mercury 40hp turn over-no start problem

I am having the same type of problem no my 1996 40 horse Mercury outboard. I was wondering if it might be the kill switch? Can you still get fire to the plugs and still not get the motor to fir if you have a bad kill switch?

 

[dac011]

Re: 1980 Mercury 40hp turn over-no start problem

I am having the same type of problem on my 1996 40 horse Mercury outboard. I was wondering if it might be the kill switch? Can you still get fire to the plugs and still not get the motor to fire if you have a bad kill switch?


Sorry about the typeO