Mercury Force 75/ser# oe197830 1996'

[joemamma_222]

Hey All Just aquired a pontoon with this motor on the back. I've heard good and bad things about force but now I Own one. I hear the factory service manuals arent as user friendly as the consumer ones (clymer/seloc) But the consumers ones often leave stuff out !
I do have a quick question on this motor though. the previous owner stated the tach stopped working and it's definately not. I opened the cowl when I got the boat home and noticed a (going on memory here) brown and yellow wire disconnected looked as if they were meant to be together and were just pulled apart. I was wondering if anyone might have a similar motor and could tell me where I can maybe stick an OHM meter and pick up a pulse for the tach ? Or can I try picking up a pulse at the tach itself and quickly diagnose the issue ? The motor I believe is not getting it's full rpm range and I dont want to lug it in the meantime. here's the link I was studying...thanks for any help !
http://www.mercurypartsexpress.com/...ection/ServiceParts/PartSelectionframeSet.asp

Joe

 

[WillyBWright]

Re: Mercury Force 75/ser# oe197830 1996'

I think you're talking about a tan and a brown wire with a white stripe. They're for gauges. Most tachometer problems are blown voltage regulator/rectifiers. They fail from loose, crossed, or corroded battery connections. It gets it's signal from the battery charging system. I think if you put a voltmeter on the battery, you'll find that it's not charging. Voltage should rise with RPMs.

The Force manuals are acutaly very consumer-friendly. They are written for techs with just the most basic knowledge of outboards.

 

[joemamma_222]

Re: Mercury Force 75/ser# oe197830 1996'

Man I hope your wrong ! lol...But Yes it';s brn with a white stripe... I'll Get her on the lake and take a look at Batt level. Should be about 13 to 14v with the motor running right ? have any idea what the brn with white might be ?
So the battery charging system hmmmm...only place to check is at the battery itself with motor running ?

 

[joemamma_222]

Re: Mercury Force 75/ser# oe197830 1996'

Actually I see the voltage regulator now in the drawings.. can I test it off of that ?

 

[WillyBWright]

Re: Mercury Force 75/ser# oe197830 1996'

Sure. Negative on the block and positive on the red wire. That's where I test when running on the hose. On the water I use the battery so the meter doesn't fall in the water. Original regulator/rectifiers have clear yellow potting in them, you can usually see a failure in the form of a brown spot in the potting. The yellow potting will get dark from excess heat around a failed component. You probably won't go much over 13v, but up to 14.75 is OK.

Brown/White is for a trim gauge and the Tan would be for a temperature gauge. Those would need sending units installed, those wires are where they'd connect to the main harness.

 

[joemamma_222]

Re: Mercury Force 75/ser# oe197830 1996'

Thanks for the info willy. I looped the motor over last night and the rains stopped me from going any further. The local library is getting me the manual and Ill be ordering one this week. Just wondering that in this pic :
http://www.putfile.com/pic.php?img=6384859

Part numer 22 is the voltage regulator ? If so I'm guessing the wire I need to test to is red ? I really want to fire it up after work today and see what I'm in for...
Thanks agian !