TOPIC: Mystery ALMOST Solved - On Blue Stripe 50 - Help!

I decided to start a new thread because the other (installing starter on Blue Stripe) was getting long and I have progressed way past the starter issue on my 1981 Merc 50.

After all my attempts to get spark.... swapping out Stator, Coils, Swithbox, Trigger, Rectifier etc from spares I had from a 1990 Merc 40 classic, it turns out it was a stupid issue with the kill circuit was the culprit( key switch, harness, or shift switch).

As soon as I disconnected the black-Yellow at the switch box she screamed to attention. As I apparently need to adjust the throttle cable it was running at way to high rpm. Of course when I turned the key off if kept running. As it was not pumping I was in panic mode of an overheat and not thinking straight. Pulled fuel line but of course it kept running for a bit..then it hit me...touched the black-yellow to the switch box and it stopped. Got pretty warm but I am hoping no damage...ran for I'd say a minute to a minute and a half.

In any case.....now that I have that solved and while I am removing the lower to change impeller and clean out tell tale etc.... Can someone give me some ideas as to how to diagnose my Kill circuit issue?

I will try my other controls to eliminate the issue in the controls(key or harness) when I get the impellar changed.

THanks and hope everyone is having a great weekend.

Tim

just brun a kill switch in place of the black-yellow wire.and be done with it.

Dave,

I assume you meant just Run a kill switch in place of that wire. As my problem seems to be in the motor side harness because it had the same symptoms with a second set of controls when attached to the switch box...no spark. Do you think it might be shorting out somewhere in there or perhaps a bad connection at the pin...gotta figure out what pin it is?

In the mean time. This is exactly why you always replace the impeller on a used motor you buy.



Of course besides the two small pieces I found in the pump I was concerned that the rest of the fins were blocking up passages in the water jacket and tell tale etc. But when I put it back together with a new impeller and fired it up....it didn't initially start pumping but after a few reams with a 12 guage electrical wire it started to flow and then a steady stream.

Now for the next issue.... I cleaned out the carbs last night(they were a bit gummy but not too bad). Now of course I need to play with the idle jet screws cause I just set initially at seated back 1 1/4 turn. She is coughing and missing at idle. I assume that means too rich so I should slowly back out the idle jets till it increases RPM a bit an levels out. Is that right?

THanks for the help as always.

Tim

the impeller was run dry as you said earlier 15-20 seconds will destroy them that way.set idle screws at 1 1/2 out from seated to start cough is lean so out is richer. turn them in slowly till it starts to slow then back out 1/2 to 3/4 turn then do it again in the water in gear.

Dave.... actually I did not say it ran dry and I certainly did not run it dry...every time I cranked it I had water on btw.... I know better. It was toast before I got my hands on it.
Pumping great now though.

In any case.. thanks for confirming what I assumed on the idle adjustment.

I'll play with it again tomorrow.

Tim

sorry about that. next time you need an emergency shut down use the choke.

Ok lets get back to my two main problems now. It is running and pumping well.

Problem #1:

The issue with the Kill Switch Black/Yellow at switch box. It wont fire with it on. I have eliminated everything outside of the motor as it happens with another set of controls. Its somewhere from the inside wiring harness in. And it is not the switch box as I swapped it out and same issue.

Problem $2:

I have it idling pretty good and adjusted the maximum advance timing, secondary pickup, full throttle stop screw adjustment etc.

Problem is ....when it is idling nicely and I manually advance the throttle to rev the engine it does not return to idle immediately..I have to adjust the idle stop screw again to bring the throttle arm back past correct idle and it eventually slows down and before too slow I manually bring it back to where it should be.

What's with this delay in returning to idle? I thought it was the trigger wiring getting in the way but when I cut the snap tie and made sure it was out of the way it still does it.

Lost and confused with these two last issues.

I ran it with a lot of Sea Foam in the small tank(a half can of Sea Foam with about a gallon of gas in the can) and after warm lifted it up and removed top three plugs and soaked with a mix of 50-50 sea foam and premix for an hour(turning flywheel periodically). Then played with it running for about 45 mins blowing smoke like crazy for a while and seems to be running well besides my issues.

Any help greatly appreciated. Hope you all had a great weekend.

Thanks,
Tim

Anybody?? Come on give it a shot....I know that answer is out there. Countless hours going through manuals and online resources and still no resolutions. She's running well and 99% there.

Tim

sounds like the ignition switch is bad just run a kill wire back to the motor operated by a momentary button as Dave already suggested....or buy a new ignition switch

Thanks for the idea but as I mentioned I have ruled out the ignition switch as it happens the same with two different controls(ignitions...unless they are both faulty?). It has to be inside the motor harness/wiring somewhere. I believe it may have something to do with one of the 3 black wires I found dangling when I bought it with no Starter/solenoid in it.

UPDATE [/b]

I think I have it figured out...it is the Mercury Switch connection. I disconnected the black/yell to it and we have spark with the other one connected to switch box.
I just fixed it....replaced Mercury switch with one from my donor Merc...not much let to donate to this baby now. I should probably put the original coils and stator back on and keep the newer ones...already grabbed the switch box back.


Also don't forget about my other issue with RPM not returning to idle speed after I throttle it up manually with throttle arm.

I guess you guys are sick of my questions but that is ok..left on my own I eventually figure it out.

Pics tomorrow of my latest good tester Merc revival.

G'night.

Tim