Merc 110 9.8 test run, need feedback please!

jsweber82

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Earlier this week I bought a 14ft Alumacraft Jon w/merc 110 9.8hp (1972 I believe) from a guy on craigslist. I am fairly new to outboards so when I bought it, I didn't know what all to look for. I had him start it up and run through the gears but that was about it.

Today I took it out for the first time. After about 10 pulls with the choke on and working the throttle it cranked and seemed to run well. The boat ramp and dock were rather busy so I tried to get out of the way asap. After about 10 mins of driving I noticed the motor was not "Peeing" the water stream as normal rather, it was trickling out a couple drops at a time. I shut it off and used the trolling motor to come back to the dock. Also, before I shut it down, I clocked the max speed with the fish finder and a speedometer app on my phone, and was about 10mph tops. So here are my questions:

1. Do you think I did damage to the motor running for 10 or so minutes without the water pump working right? It was a pretty chilly day, didn't see any smoke or signs of overheating.
2. Does 10mph seem right for this boat and motor? I have seen youtube videos of guys getting 25mph from a similar setup.
3. What maintenance should I do right away given I don't know the history? I plan to change the plugs, clean the carb, change the gear oil, and I have an impeller repair kit on order.
4. This question shows how much of a noob I am with outboards...When do I use the "Shift" on the trottle handle? i was using it to change from neutral to F, F to netural, N to Reverse etc. Am i missing something?

Sorry for the dumb questions. Still have A LOT to learn.
 

tpenfield

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Re: Merc 110 9.8 test run, need feedback please!

I usually keep a piece of 'weed wacker' line with me to stuff up inside the pee hole to clear out clogs, etc., since the Mercs of that vintage do not have much of an intake screen on them.

I believe water flows out elsewhere though, it is just a tell tale.

10 mph sounds a bit slow . . . I have gone 13 mph with my 1969 7.5 hp Merc, which is substantially the same engine as yours. It kind of depends how loaded up you were, etc.

I would doubt that you damaged anything

the "shift" label on the twist throttle is just to let you know how low to have the throttle in order to be able to shift into and out of gear. It is a visual reference, yet I believe there are some throttle linkages connected to it as well. You want to be at or below the shift mark on the throttle when shifting.

As far as maintenance, I picked up a 1969 7.5 Merc this summer and had to replace some seals in the lower unit and rebuild the fuel pump. Just finished the fuel pump today. Also had to replace some cruddy wiring. Your motor is 41 years old, so certain things will need to be replaced partly because of age.

here are my stories with a vintage Mercury outboard: http://forums.iboats.com/non-repair-outboard-discussions/i-got-me-mercury-617939.html

http://forums.iboats.com/mercury-mariner-outboards/1969-mercury-7-5-fuel-pump-629345.html

I hope that helps
 
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jsweber82

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Re: Merc 110 9.8 test run, need feedback please!

Thanks Ted, this does help.

I took the pee hole hose off and blew compressed air though it and cleaned it, same with the intake hose in the lower unit. I also inspected the impeller and it actually looks to be in good shape. It is all in tact and the rubber still feels new. Any other ideas why it wouldn't be flowing properly?

as for the top speed, I am no expert but after examining the throttle, I feel like it has something to do with the throttle adjustment. When I twist the handle from "start" to "fast", there is almost a quarter turn where nothing happens. The throttle handle will max out and the carb will have just opened a smidge. Do you know how I can adjust this?
 

tpenfield

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Re: Merc 110 9.8 test run, need feedback please!

mineral deposits in the cooling system can clog the pee hole, as well as things that get sucked in the cooling system can do the same. When I first got my engine (in July) the pee hole was impacted with mud.

The age of the engine has something to do with it, but I had a Yamaha 8hp a while back that was only about 12 years old and it did pretty much the same thing, I was constantly unclogging it.

There are some stop adjustments for the throttle control up near the flywheel (IIRC), but the throttle linkages are fairly bullet proof on those engines. The 'gear mechanism' that is in the pivot point of the control handle could be out of adjustment or even slipped a tooth.

I use marine engine site for parts diagrams, etc. Mercury Marine 110 THROTTLE CONTROL LINKAGE Parts

The engine should rev up fairly high under load and at full throttle, so that could be an indicator if you are getting the full extent at the carburetor.
 
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bgc

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Re: Merc 110 9.8 test run, need feedback please!

You're off to a good start with your maintenance plan.

The impeller is cheep compared to burning up an engine.
If the fuel pump kit is not included in the carb kit, get one.
When you drain the lower unit oil, look for signs of water.
The Throttle Control Linkage will start to advance the spark before opening the carbs. There is then a synchronous, advance and opening till the Max Spark Advance and then just the carbs open, till the butterfly valve is full open. This is know as Link-N-Sync.
If you post the first 5 digits of your serial number, Ill check my manual.

There are many factors to getting max speed on the water. Getting her running at top performance is the starting point.
 

jsweber82

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Re: Merc 110 9.8 test run, need feedback please!

Bgc, unfortunately I don't know the serial number. It looks like it was scratched off. Based on the cowl cover decals I believe it is a 1972 or 73 though. Last night I took out the carb and disassembled and
Cleaned it. It really didn't look too bad. A couple loose sediments but not as bad as I expected. I also cleaned out all the water hoses and intake. Hopefully that will fix the cooling flow since the impeller looks good. I definitely think my speed issue is throttle related. At full throttle, the carb is only partially open. It can go much further to get the butterfly wide open. Now I just have to figure out how to adjust. I downloaded a 500 page PDF service manual for $4.95 from a site online. It covers the 110 models from the 60's to 80's. Hopefully it will tell me something!
 

bgc

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Re: Merc 110 9.8 test run, need feedback please!

Is the carb and fuel pump integrated your your motor or is it two separate componets?
 

jsweber82

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Re: Merc 110 9.8 test run, need feedback please!

I am pretty sure it is all one unit but have attached a pic for you to see. Also, I was in the garage just now and found a needle and spring (inlet needle?) on the floor which must have fallen out when I cleaned it last night. Where does this needle go? Pic attached. carb 2.jpg
 

MH Hawker

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Re: Merc 110 9.8 test run, need feedback please!

From what I can see those are the float pin ears sticking out, so in that general area is where the needle goes.

carb 2.jpg
 

jsweber82

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Re: Merc 110 9.8 test run, need feedback please!

Throttle 1.jpgThanks MH. I think I found where it goes. It fit into a little hole under the float to create a spring action to the float opening and closing.

here are a couple pics of my throttle. In the first pic this is wide open, with the stopper at the bottom keeping it from going any further.

In the second picture, I am pulling the carb open completely. As you can see there is a ton of space between the two. Does this look right? I can't figure out how to adjust it. Throttle 2.JPG
 

AMD Rules

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Re: Merc 110 9.8 test run, need feedback please!

Don't forget, you cannot typically advance the throttle very much when the shift lever is in neutral, that -may- be what is holding it back. Try moving the shift linkage forward.
 

jsweber82

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Re: Merc 110 9.8 test run, need feedback please!

I will definitely buy the gasket kit. I put in fwd gear but cannot advance the throttle more than when it was in neutral. Just for reference, at WOT should the carb be completely open? At full throttle the carb doesn't open more than 1/4 of the way I would say, maybe even less.
 
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