1971 Mercury 115 Inline Six Cylinder Woes......

[Theoutdoorsman]

I had the carbs overhauled early this year thinking this would solve my problems with power loss. And it did........ for about two weeks. Then, as I was returning to the ramp one evening after fishing, It was as if I'd lost 1/3 power. Next trip out, I couldn't even get the boat on plane. Thinking maybe it was something that I did, I took it to the lake one more time only to NOT have the first problem out of it. And I didn't touch a thing either. The same holds true for about the next 2 or three trips. NO problems!!! Then it does it agan!!! Can't get on plane again!!! Currently, I can't get above an idle without the motor stalling out !!!!!! I haven't had it back to the lake since. Does anyone have any idea what might be causing the problem? I'm at a total loss here !!!!!

 

[Theoutdoorsman]

Re: 1971 Mercury 115 Inline Six Cylinder Woes......

One more thing..........this happened a couple times........While the boat was still on the trailer at the ramp and getting ready to launch, I lifted the lever for the fast throttle, pushed the choke button, turned the key.............and the crazy thing reved up to point I thought it would blow up.......??????........ Scared me to death. Afterwards, I couldn't get the boat on plane..........?????

 

[Theoutdoorsman]

Re: 1971 Mercury 115 Inline Six Cylinder Woes......

HHHHEEEEELLLLPPPP!!!!!

 

[rockytop93]

Re: 1971 Mercury 115 Inline Six Cylinder Woes......

The first thing I would check is the throttle cable. Maybe it is slipping around in the bracket and not opening the throttle at times. Just a guess.

 

[catmania]

Re: 1971 Mercury 115 Inline Six Cylinder Woes......

power pack crapped out? <br />Wonder how you test them? or just replace and get it over with...

 

[rodbolt]

Re: 1971 Mercury 115 Inline Six Cylinder Woes......

Hello<br /> I had a trigger on my 150 do the same thing. no good way to trouble shoot them. dang hard to change . check all else do the basics then do the trigger

 

[Gold Bear]

Re: 1971 Mercury 115 Inline Six Cylinder Woes......

Theoutdoorsman <br /><br />Sounds to me like a problem with the fuel pump(s) diaphram.<br /><br />I would change out the diaphram in both fuel pumps.<br /><br />Do you have a fuel filter installed in your fuel hose? If not I would install one of those clear inline filters.<br /><br />Good Luck,<br /><br />Gold Bear

 

[mellowyellow]

Re: 1971 Mercury 115 Inline Six Cylinder Woes......

check pumps as mentioned, but...<br />she is sucking air not fuel IMO.<br />from where???<br />good luck,<br />M.Y.

 

[greasemonkeyozi]

Re: 1971 Mercury 115 Inline Six Cylinder Woes......

Oh boy, I know your problem too well, and I have some good tips you can do yourself. Mellow Yellow is right, you may have air seeping into your fuel system somewhere. (1) check for any obvious fuel leaks from your tank to your carbs. Dont check it when motors running, you will be wasting your time. The vacume from your motor would be sucking in air instead of spitting out fuel in your suspected leak. (2) Go to your local parts store or wal mart and buy enough of those screw tight metal hose clamps. I have noticed that the manufacturers use those cheap plastic zip ties for hose clamps. Why, I dont know. Add those metal hose clamps on ALL hose ends including your waterhoses as well. (3) replace your connector fitting that connects your fuel line to your motor, if its the same kind of fitting I'm thinking about, those things have a rubber O ring in it that seals the connection. In time, that O ring will dry rott. I had that problem once. You can get this part at wall mart along with other basic boating parts. (4) replace that fuel fitting that goes on your tank that connects the fuel line. (5) replace your primer bulb. (6) Go to your local dealer and ask the parts dude for a fuel pump diaphram rebuild kit for your motor. A good $5.00 simple do it yourself job. There is a possability your diaphram has a small hole in it, or a gasket has gone bad. <br /> Its good to know you have had your carborators rebuilt, I just hope the mechanic who done this adjusted your idler jets right. Before you worry about your carbs, redo your fuel supply system first. If you know your stuff, this small project can cost under $30.00. Good luck.

 

[NEECAPRS]

Re: 1971 Mercury 115 Inline Six Cylinder Woes......

THEO: Lots of possibilities and ideas here. Your runaway episode on the ramp sure puts a unique slant on this. Following the possibility that Rockytop brought up, can you arrange to have a first mate remove the front cowling cover the next time it won't even plane. Trying to make sure you don't have a simple problem with throttle linkage or actuator cables. When it won't plane, are the carbs open and distributor advanced?<br />BTW, after the trailer episode, you've surely checked to see that the water pump is okay!!?

 

[DJENAN]

Re: 1971 Mercury 115 Inline Six Cylinder Woes......

do what mercurygreaserag said!!!<br />i bought the kit which has the primer bulb, both connectors & fuel hose for $40AUS and it seemed to fix a similar problem i had , as the original ones were 20 years old and looked stuffed. no point stuffing around replacing one part when they are all probably just as perished.<br />If this doesnt fix it then look at other alternatives, eg throttle cable, carbies etc etc