Stator bad? 175 HP - 1979 Black Max

[keviwe]

I have a 1979 Mercury Black Max 175 HP V-6. Serial 4733877. It has run fine for years. Engine starts fine and idles fine but at throttle up, RPM increases a bit but just hangs at maybe 1,000 RPM. I got it past the "dead spot" once and when "over the hump" it ran up to full RPM, but after throttling down it still won't get past the "dead spot". I am told it's a stator - (the low side) How should I test to make sure (if you think it could be something else) Please advise. All I have is a basic digital meter. I'll need a flywheel puller too, let me know where to buy one.
Thanks,
Kevin in Colorado

 

[schematic]

Re: Stator bad? 175 HP - 1979 Black Max

can't see a stator doing this. Try enriching the idle mixture adjustment. Could also be as simple as fuel starvation from weak fuel pump, air leak or supply restrictions.

 

[keviwe]

Re: Stator bad? 175 HP - 1977 Black Max

Re: Stator bad? 175 HP - 1977 Black Max

can't see a stator doing this. Try enriching the idle mixture adjustment. Could also be as simple as fuel starvation from weak fuel pump, air leak or supply restrictions.

The motor did sit for 4 years, then when finally run, it acted up. When it would not accelerate above 2000 RPM - under a load (it revved up fine in the driveway with water muffs on), I did squeeze the fuel primer bulb many times. This would eliminate the fuel pump being "weak" right? It idled fine and could have idled all day, so I hate to fiddle with the idle richness adjustments. It did finally rev up to full RPM and I drove around for about 20-30 minutes at higher RPM, and it ran fine. Then when I idled down it wouldn't rev back up again (just to about 2,000 RPM again). Since it ran fine before I stored it, I should not have to "rebuild" the carbs (@ $91/carb right??...Just a good cleaning, correct? (if this was a car I would replace the accelerator pump but when looking at the rebuild kit, I see no accelerator pump correct?) Oh, yeah, it's a 1977 not a 1979
Any more suggestions you have are appreciated!

 

[Barnacle_Bill]

Re: Stator bad? 175 HP - 1979 Black Max

If your idea of a good cleaning means taking the carbs apart and thoroughly cleaning them properly then yes. But I would be silly to go to that much trouble and not put them back together with new gaskets, needle and seat. You are correct, no pump.

 

[quicktach]

Re: Stator bad? 175 HP - 1979 Black Max

Check for a sticking advance mechanism. The trigger coil may not be advancing, holding you at the dead spot. Check all your linkages for jam ups.

 

[keviwe]

Re: Stator bad? 175 HP - 1979 Black Max

If your idea of a good cleaning means taking the carbs apart and thoroughly cleaning them properly then yes. But I would be silly to go to that much trouble and not put them back together with new gaskets, needle and seat. You are correct, no pump.

Yes, if I clean the carbs I will definitely put new gaskets and needles and seats.

What website can I find a cross to Sierra part #"s. I have a 1977 Merc 175HP serial 4733877, Mercarb 1374-5427 WH-1

 

[keviwe]

Re: Stator bad? 175 HP - 1979 Black Max

Check for a sticking advance mechanism. The trigger coil may not be advancing, holding you at the dead spot. Check all your linkages for jam ups.

Thank you for this advice. I'll check it and let you know. I can do this without the engine running right?
So if there was a sticking advance mechanism would it still rev-up with no load like it did in the driveway with the flush-muffs on?