mariner inline 6 stalling???

illinoisbassfishin

Seaman Apprentice
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Jun 13, 2010
Messages
49
The last few times I have been out the boat is stalling out of the hole for some reason. It just kept getting worse and worse every trip the last 5-6 trips since the 1st of july. So today I put new ngk plugs in it and thought that would help. It still didn't resolve the problem. Last summer is when I got the boat and it ran like crap when I got it. We had the carbs rebuilt, the fuel pump rebuilt, new fuel line and bulb, did a link and synch on it, and put all new seals in the lower unit and all new water pump housing and everything. Did all that work and it ran like a champ and did excellent all summer and winter at a power plant lake up until about a month ago. It will idle great, and put in gear it will run good till it hits about 2500-3000 rpm and then it starts bogging real bad and it takes forever to get up to speed. Once it is planed out it will reach it's 5000-5200 rpm range and run about 45 mph. It will still push itself up on the trailer and has plenty of power to do that as well. It is a 1983 mariner 115 inline 6 and when it was at the shop it also had a compression check as well and I can't remember exactly what the numbers were but he said 5 cylinders were just about exactly the same and one cylinder was a little lower but it wasn't much difference to worry about much. After I put new plugs in it and it did the same thing all I can think is maybe it has lost a little time again?? If anyone has any ideas of what it could be any opinions are appreciated. Thanks.
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: mariner inline 6 stalling???

First check the carbs, a slightly lean idle mixture will not accelerate well yet seem to idle perfect all day. Turn the idle mixture screws out just the width of the screwdriver blade and retest your acceleration. repeat to perfection.

If the motor hangs in the 2 to 3000 range it may be a weak hi speed stator winding however this must be properly tested with a DVA meter before ordering any NON-returnable electrical part.

Go with the idle mixture adjustment first, see if that cures your problem.
 

Droll

Chief Petty Officer
Joined
Jul 30, 2003
Messages
514
Re: mariner inline 6 stalling???

it will reach it's 5000-5200 rpm range and run about 45 mph.....
It is a 1983 mariner 115 inline 6

A bit low WOT rpm ? 5700 > 5800 would be better...


Arne Kjetil
 

illinoisbassfishin

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Joined
Jun 13, 2010
Messages
49
Re: mariner inline 6 stalling???

hey charlie thanks for the advice. Is it possible that the carbs could have came out of adjustment in a years time after the link and synch. I just hate to mess with the carbs after I already had it to a shop and had it done. Although it has been almost a year since they did the link and synch.
 

illinoisbassfishin

Seaman Apprentice
Joined
Jun 13, 2010
Messages
49
Re: mariner inline 6 stalling???

well i just got done talking to a local merc shop that is close to here on the phone. Something he brought up I never really thought about is right before all this happened we added a 3rd battery to the boat. We had a 24 volt trolling motor but didn't have room for a 3rd battery until we did some modifications till we made room for it so we were just running the 24 volt trolling motor with the two batteries and using one of the batteries as a starting battery since it was a dual purpose battery. Those two batteries were bought brand new when we put them in. We finally had time away from work to put in the 3rd battery. The battery we put in was a group 24 trojan marine starting battery but it had been sitting on a wood block in the garage in the heat and cold without being charged at all for about 3 years. Finally one day my dad needed it to jump start our riding lawn mower so he charged it and used it to jump start. The battery was dead at first and wouldn't even jump start the mower till he charged it. Now that I told you the details of the starting battery that is in the boat I will tell you that the mechanic I talked to said that if the battery is weak or has a dead cell or two dead cells etc., that this particular motor runs off of a cdi ignition (which it does because there is a label on the motor that says cdi) and if the battery is weak or no good it will cause the motor to not get enough battery power to accelerate and run right. Now that I have heard this I realized that all my problems did start happening after we added this battery. Any opinions about this?
 

illinoisbassfishin

Seaman Apprentice
Joined
Jun 13, 2010
Messages
49
Re: mariner inline 6 stalling???

Well it wasn't the battery being weak issue that the first mechanic shop told me to try. Switched the outboard over to a new battery and it still is bogging down at 2800-3000 rpm and takes forever to get past that. Finally talked to the mechanic that has did all my other work and he said try to pump the ball when it does that and see if it takes off then. That didn't do anything but flood it out so I know it's not that, so he said if that didn't do anything for it the only thing he can think of is the stator as someone else on here said too. Just ordered a stator from here on iboats and I will install it when I get it and see if that fixes anything.
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: mariner inline 6 stalling???

First check the carbs..........

If the motor hangs in the 2 to 3000 range it may be a weak hi speed stator winding however this must be properly tested with a DVA meter before ordering any NON-returnable electrical part.

Go with the idle mixture adjustment first, see if that cures your problem.

Changing out electrical parts because 'somebody; says it 'might be' the problem is often THE most expensive method of repairing a problems. You can end up replacing the entire ignition system until you change the defective part.

Proper testing following the tried and true PROVEN DVA method spelled out in the service manual and the FREE Ignition Troubleshooting Guide available for download on the Support page of CDIElectronics.com is the safest and most cost effective method of diagnosing and repairing any ignition problem.
 

illinoisbassfishin

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Joined
Jun 13, 2010
Messages
49
Re: mariner inline 6 stalling???

The mechanic that told me it was more than likely the stator is the same mechanic that has did all my work and has helped me through everything else I have done to the motor and he has yet to be wrong yet. He's been working on Merc and Mariner exclusively for 25 years now and he really knows what he's talking about. I trust him being that he hasn't let me down yet and the stator isn't expensive anyways so if that doesn't fix it I'll just have a new stator which can never hurt anything.
 
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