1967-1969 Merc 110 10hp outboard problems

[Ryan's outboard]

I have a merc. 110 10hp black outboard. Just started it this year and ran great off the first couple pulls, I'm running it full boar for about 5 mins and it just stops. Won't turn back on. Get it back, wait about an hour, start it back up, ran it in neutral full power for about 2 mins, took off driving kills on me mid flight,after 5 mins at full power. The engine just stops and then wont turn back over, waited about 20 mins and it starts again and then ran fine at less power for about 10 mins straight until i stopped it. Any suggestions, thanks

I forgot to add that its a 1967-1969, not sure exactly what year, but around there. I'm not sure if it has a thermostat, that shuts it off because of running at full speed. Maybe its something with the fuel pump, but then when it shuts off it wont turn back on the ball is hard and it seems to take about 15 mins before i can start it again. Also has a fresh tank of gas I just put in.

 

[Scaaty]

Re: 1967-1969 Merc 110 10hp outboard problems

Hmmm..
Anyone want to touch this..
"ran it in neutral full power for about 2 mins"

 

[Harker]

Re: 1967-1969 Merc 110 10hp outboard problems

Not sure how it could be ran "full power" in nuetral. Does it stop slowly or with a clunk? Is there water coming out the pee hole and the exaust ports? Does it only stop when "going full" power or can you "putt" around without it stopping?

 

[Ryan's outboard]

Re: 1967-1969 Merc 110 10hp outboard problems

Its defiantly spitting out water, it stops very suddenly, just like I hit the stop button and in the time I was running it, it would only stop when I was at or near full throttle. Lasted longer when I was going at half throttle, but didn't run it long enough to die, but it defiantly lasted longer. I called an outboard repair shop as soon as I said old mercury, dies suddenly when I'm at full throttle for about 5 mins he said he knew exactly what it was and it would be around $80 to fix. Is there a thermostat on this thing?

 

[Harker]

Re: 1967-1969 Merc 110 10hp outboard problems

No, they don't have thermostats. Did he say what he thought it was? First thing I'd check was that my tank was venting properly..then the fuel pump and carb.Does the motor feel real hot when this shutdown occurs? When was the impeller changed last?

 

[Ryan's outboard]

Re: 1967-1969 Merc 110 10hp outboard problems

No he was real quiet about what it was. I was thinking fuel pump too. Engine doesn't feel hot at all and its peeing alot and the water coming out is just warm. The water impeller was changed last year at this time. When I open the cover and look by the choke where the carb is, its the only thing on the engine that looks new and shiny, and it looks 100% clean on the inside from what I can tell. Is the fuel pump an easy task?

 

[Harker]

Re: 1967-1969 Merc 110 10hp outboard problems

Pretty easy..I'd get a carb kit with float and a fuel pump kit from Old Mercs.com. They have a thing on their site where you can match your serial number and find the year. How do the olugs look?

 

[Ryan's outboard]

Re: 1967-1969 Merc 110 10hp outboard problems

Looks like the carb is new and very clean. Spark plugs are 2 years old but it fires up fine. From what I see at old mercs.com the fuel pump kit is just some gaskets, its not leaking anywhere, maybe air getting into the gas there? I also see a filter?? Could my filter be clogged and when the rush of fuel hits it finally gives out? I can just see myself going to get this repaired and getting charged $90 for a fuel filter. I also notice that the engine shakes like a leaf and runs very rough, is this tied to the problem?

 

[billybones]

Re: 1967-1969 Merc 110 10hp outboard problems

you never stated whether the tank was venting properly or not. is the bulb collapsed when the failure occurs? My 7.5 shakes a lot. But smoothes out in gear.

 

[Harker]

Re: 1967-1969 Merc 110 10hp outboard problems

It doesn't matter that the outside is clean..and most of the time when you take the carb apart it "looks" clean as a whistle..it's what is in the passages where the gas goes that matters. A speck of crud can mess everything up. The pump kit has gaskets and a diaphram that looks like a gasket..if the diaphram is worn out it won't pump gas very good. My 67 9.8 doesn't have a filter. I guess that could cause some problems. Pop a plug when it happens to see if it's dry. I ran a can of Sea Foam through mine also and it smoothed it out quite a bit.

 

[Ryan's outboard]

Re: 1967-1969 Merc 110 10hp outboard problems

Yea, I ran 3 cans of sea foam through it last year and it kept it working but only smoothed it out while it was in tank. Could I get some carb cleaner to spray in there? Would that even matter? But thanks for the replies, I'll keep everyone posted on what happens and what fixes it.

 

[Wellwater]

Re: 1967-1969 Merc 110 10hp outboard problems

I have a 1964 9.8 with the same problem. I have found I can pump it up then it will run great for about 2 min. then dies quick. I have replace fuel pump diaphrams changed fuel line from motor too tank ,changed my tank checked and rechecked fuel pump housing for cracks or leaks .I am out of ideas also in need of help in this area. I also want to add bulb is hard when it gets pumped up and bowl is full at that point, when the motor dies the float bowl is dry and I can fill it back up or keep the motor running by continous pumping by hand. This motor ran great last fall and was stored indoors. I just know it is something simple causing this just cant figure it out.

 

[jebeebe]

Re: 1967-1969 Merc 110 10hp outboard problems

If it was me, I'd try leaving the tank cap loose and trying it again.........Jerry

 

[Wellwater]

Re: 1967-1969 Merc 110 10hp outboard problems

I was thinking of a vent problem and also tried a loose cap on both tanks used . If it was a venting issue I think the hose would collapse if the pump was working correctly. thanks for the input

 

[Harker]

Re: 1967-1969 Merc 110 10hp outboard problems

Did you change the float and inlet needle? Carb cleaner will work..if...you take the carb off and dis-assemble it..spray it through all the holes and nooks and cranniesDid you put the pump back on right? Inlet to inlet and outlet to the carb? There is some little check valves in there that can go bad too.

 

[Wellwater]

Re: 1967-1969 Merc 110 10hp outboard problems

On mine I have replaced the inlet needle and seat and checked out the float which is good .Took carb off and soaked and cleaned,It runs great when gas is in the bowl.Those check valves I am going assume are in the pump housing that the lines are connected too. If so, I can pump gas through them into the carb .As far as backfeeding I will need to check and see if I can blow back towards the tank. Hoping that would be a logical test for a check valve here. If the valves where too be bad does this mean I would need a new pump housing or are they removable or replaceable.Thanks Harker didnt realize these check valves existed. The pump was never disconected from the gas lines when cleaned and replaced diaphram gaskets.

 

[Harker]

Re: 1967-1969 Merc 110 10hp outboard problems

Not sure about a 64 but the check valves in my 67 are little tubular looking deals that are pressed into the fuel inlet hole on the pump. Your problem sounds like it's fuel pump caused since it works when you become the fuel pump. Is yours connected to the engine block? Or does a tube hook to the block and run to the pump? Wondering if your getting pulse to the diaphram.

 

[Wellwater]

Re: 1967-1969 Merc 110 10hp outboard problems

The pump mounts to the side of the block with 4 screws which also hold the pump together. I located the check valves that are pressed into the pump housing . With the pump off I can blow through the pump in both directions. the valves look good and I can see a plastic covering on both that look to be in good condition, with no holes or cracks. I have good compression on both cyl. and blew out the vacumm holes ,resealed that access plate on the side of the block . any other ideas are welcome here. The ball pumps up hard so I dont think that I have any leaks in the gas lines.

 

[Harker]

Re: 1967-1969 Merc 110 10hp outboard problems

You should only be able to blow one way through the pump. If your float chamber is being sucked dry..I would have to think that it's either pump related or a sticky inlet needle. Did you adjust the float height levers according to the manual or instructions with the rebuild kit?

 

[Wellwater]

Re: 1967-1969 Merc 110 10hp outboard problems

My needle and seat works great and the float is working good and adjusted the bowl fills when pumped up and cuts off when full . I just cant get the pump to assist in gas delivery to the bowl I will have to either try to get a different pump housing with new check valves. This is all that is left to do i believe, since I can blow backwards toward the tank through the pump. I just wonder even when air passes backwards ,if gas would act differently under pressure through those check valves.