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45hp 4cyl manual and basic maintenance

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Mustang67ford

Member
Recently got a 1986 classic fifty. Looking to see what manuals are available and what to do for typical maintenance. Will be changing the gear lube soon, the boating season is just about over. I want to give it a good visual inspection over the winter and replace any worn parts. I had somebody else put it on the boat so want to make sure all is hooked up good. I believe the plugs were changed. I seen pics of one with a glass fuel filter so might put one of those on. Also, what other signals am i able to get back to the gauges? I learned the lower hose is for speed, bu td can i get any temps, rpm, or any other usefull info? Thanks.
 
Some things I have done for my '92 Merc 40 4cyl 2stroke:
Use non ethanol gas,
Do a compression test and note,
With a VOM meter check Ohm readings on stator leads, trigger leads, coils and compare to factory spec and note.
End of season: change gear lube, treat gas with Stabil, fog engine, drain carbs, spray fogging oil in each cylinder; if stored outside, pour RV antifreeze into exhaust hub and cover hub.
 
RickM46 said:
Some things I have done for my '92 Merc 40 4cyl 2stroke:
Use non ethanol gas,
Do a compression test and note,
With a VOM meter check Ohm readings on stator leads, trigger leads, coils and compare to factory spec and note.
End of season: change gear lube, treat gas with Stabil, fog engine, drain carbs, spray fogging oil in each cylinder; if stored outside, pour RV antifreeze into exhaust hub and cover hub.
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Thanks for the info
 
Having the shop manual for mine was priceless: rpm specs, carb adj procedure; carb dis-assembly procedure and pictures; electrical specs.
 
No, mine is not a seloc; when I bought my engine in '92, I also bought the shop manual for it written by Merc/Brunswick corporation; it has lots of dis-assembly and re-assembly pictures and procedures; don't know if seloc has that.
 
Do a compression test for now and also for future reference.----Change impeller for water pump and lube crankshaft splines on re-assembly..-----Pressure test gearcase.-----Make sure the motor has the correct propeller for your boat.----Some aftermarket manuals belong in the little house with the moon in the door.
 
Good info, will look for a regular manual. I'm going to be changing the crankcase fluid soon. I think the compression was all over 110 per tge company i bought the motor from. Ho do you grease crank shaft and pressure test gearcase?
 
Mustang67ford said:
Good info, will look for a regular manual. I'm going to be changing the crankcase fluid soon. I think the compression was all over 110 per tge company i bought the motor from. Ho do you grease crank shaft and pressure test gearcase?
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I think greasing the crankshaft refers to the top of the drive shaft that gets exposed when you drop the lower unit.

I saw a pressure test device used on my Merc I/O unit: it was composed of a type of hand air pump used tp pump up basketballs and footballs with a gauge on it and a flexible line that could be attached to the vent hole of the lower unit; the mechanic mentioned that about 15 lbs of pressure was pumped into the lower unit and let set overnight; the pump was left connected and its gauge examined to see if there was a decrease in pressure indicating a leak that would result in loss of gear lube.
 
I changed one in my Merc I/O; bought parts from a dealer; there are plenty of threads on this forum on how to do it and, I bet, Youtube videos; not hard to do with regular hand tools; some say that it gets ugly if you try to change the base plate under the impeller but that it is not necessary to change the base plate.
 
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I did notice when the dealer lowered the lower unit, there was some type of like heat shrink or something on the lower part of the driveshaft / crankshaft threads. They said it was a dust shield. I had watched them lower it a couple times to get the reverse lock working, but that is another issue. Still havent been able to confirm what this dust shield was.
 
The dealer said it was a " dust shield " ?-----Does your motor have an air filter ?-----I doubt it.----So why would they tell you it is a dust shield ?
 
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