50 hp no fire

[imported_skraps]

Can anyone tell me where to find the ign wire at the engine? I want to connect 12 volts to make sure the ign switch is not my problem. It will some times start and run 2 seconds and stop wont start for 30 trys after. I know its not a fuel problem because priming it does no different. Thanks

 

[Laddies]

Re: 50 hp no fire

Don't start hooking jumpers till you find out if it's ADI, magneto or battery CD you will burn the system up. What is the year or serial number?

 

[BillP]

Re: 50 hp no fire

Might be something real simple. That's what my 50hp did the first time I forgot to plug in the safety lanyard. It would start, run a sec or two and quit. This went on for a few minutes before my brain went into gear and figured out the reason. My other (OMC) motors won't even fire with the lanyard deal detached...but the merc/mariner does.

What 50 is it? When my 50 mariner 4 stroke (yamaha head) was new it would randomly stop like the key was turned off. It would start back up like nothing happened and did it a couple times the first month. The dealer couldn't make it happen or fix it but I finally found the culprit after getting stranded. The main harness plug (under the hood) has rolled pins that plug into the female side. The pins are slit down one side and hollow. As a last resort I spread each pin a tad to make it larger and give better contact. It never quit again after that and it was 12 yrs ago, so I must have struck gold with the fix.

 

[imported_skraps]

Re: 50 hp no fire

Its A 1978 500 50 Merc With 4 Coils And A Cdi Box .

 

[imported_skraps]

Re: 50 hp no fire

Any ideas?

 

[Laddies]

Re: 50 hp no fire

Thats ADI ign. do not hook 12 volt to it or the system will be damaged, it's a ground off system so goto the switch box and disconnect thee black/yellow wire if it has spark then, the switch could be bad if it don't have let us know and we can give you the test specs. for the system.

 

[imported_skraps]

Re: 50 hp no fire

by switch box do you mean the black box next to the coils,if so i cant find a black and yellow wire there.

 

[Laddies]

Re: 50 hp no fire

OK, a 78 may have a orange wire instead of a black/yellow for a kill wire.

 

[imported_skraps]

Re: 50 hp no fire

Removing the orange wire made it start and run. It runs now on three cylinders allways ran on four and smooth. While running i put the wire back on and it stopped running. Nothing ever comes easy huh? will start hard now but runes terrible.

 

[Laddies]

Re: 50 hp no fire

There is a short in he ign. kill circurt that needs repairing and I hate to bring it up but did you arc the system with 12 volts?

 

[imported_skraps]

Re: 50 hp no fire

Laddies i have only removed the orange wire and no 12 volt junping has been done. I thought the orange wire being removed would tell me that the problem would be from there to the switch. If thats correct how could there be a problem with the wire removed? It did start and run but why the miss? Thanks

 

[Laddies]

Re: 50 hp no fire

Whwn you removed the wire and the engine started that proved the main problem is in the switch or wiring and the reason I asked about the possibility of the system being touched with 12 volts goes back to the start of the thread when you were trying to jump the switch. Anyway here is a system test from CDI.

 

[imported_skraps]

Re: 50 hp no fire

Off to the merc dealer. Thanks

 

[BillP]

Re: 50 hp no fire

Black or red stator?...black is bad, red is good.

 

[Laddies]

Re: 50 hp no fire

Both are junk compared to a CDI stator