'83 Merc 150 - Stator replaced, still not right

[ratlsnaktj]

I was having trouble with my engine not getting full power. It tops out at about 2500rpm or so. After testing the stator a few months ago I found the low speed windings to be bad. I've replaced the stator (and rectifier) but I'm still having the problem.

There is spark on all six plugs (brand new) and good compression on all cylinders.

What should I try next? I was thinking about doing a SeaFoam treatment to see if that'd help. Any thoughts?

 

[Chris1956]

Re: '83 Merc 150 - Stator replaced, still not right

I would check the link and sync, and make sure the ignition timing is correct.

BTW - If the low speed windings on your old stator were bad, the motor would not run slow, it would run only fast.

 

[ratlsnaktj]

Re: '83 Merc 150 - Stator replaced, still not right

How do I go about doing the checks you suggest? Don't think it sounds like a possible fuel related problem like carbs or something? The boat hadn't been sitting long so I doubt sour fuel, but it just feels fuel system related. Are you advising against the SeaFoam treatment?

You're correct, that was a typo, nonetheless the stator had open resistance and needed to be replaced.

 

[j_martin]

Re: '83 Merc 150 - Stator replaced, still not right

I think it's possible to have linkage problems give you those symptoms. It's also possible that you have a bad switchbox.

Get a manual and start with the link n sync. Without having a known starting point, troubleshooting, especially by remote (internet) is pointless.

hope it helps
John

 

[hkeiner]

Re: '83 Merc 150 - Stator replaced, still not right

After performing the link and sync, doing some basic systematic troubleshooting tests may be the best and least frustrating thing to do next. Following are two troubleshooting guides I have found to be usefull in the past. If you follow both of these guides and report the results, you will most likely get some pretty good ideas for solving your problem, or at least eliminate a lot of possible causes.

Ignition: http://dolphinmarineservice.homestead.com/ign5.html

Fuel: http://www.marinepartsman.com/Mercury-Marine-service-bulletins/Mercury-Mariner/2001/EN_17.PDF

 

[ratlsnaktj]

Re: '83 Merc 150 - Stator replaced, still not right

After reading some other posts on here I think timing could be the issue. Hopefully it will be as simple as that, though my problem is eerily similar to the one on a thread by Kendo.

My manual does not list the idle rpm in forward gear the '83. The first year with this spec listed is '87 at 600-700rpm. Does that seem about right for an '83 as well?

Also I have seen other threads that recommend just removing the idle stablizer all together...is that something I should do as well?