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Mercury 110 9.8 HP - 1971 - Won't Start

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RicknDee Huntington

New member
I can not get my Mercury 110 to start
So far I checked :
1. Compression > then 100 psi
2. Cleaned Points
3. Checked Coils (both 532 ohms)
4. Checked the wiring with the diagram (switched wires on coil 1 to match diagram)
5. Cleaned carburetor - new bottom needle, cleaned filter and pump.
6. Checked top dead center on #1 cylinder, mark (one of the 2 marks) line up with factor markings

I have a good spark on both cylinders

I am currently think this may be a carb problem / plugs are normally wet

I have been getting a little bit of a spud-er every once in a while

I will be grateful for any suggestions
 
"Cleaned carburetor"...did you completely strip it, soak it and blow out all fuel passages w/compressed air? Since the plugs are wet the fuel pump probably is working. There has to be a back pressure pulse created by the pistons moving in order for the fuel air mix to be forced into a cylinder or it won't fire. If you have some Seafoam spray or just liquid use something to get a 1/2 teaspoon full into each cylinder and install the spark plugs tight. Crank it to see if it fires. If it tries to start you may have an upper/lower crank case seal failure.
 
Have you tried starting fluid (ether)? You'll get a bunch of guff on that being "dangerous" to your engine (it contains no oil) but it isn't when the motor already has lots of oil inside; and that's the problem--it's flooded with oil.

I've seen many a stubborn Merc 110, so try this:

1. Plug and clean the plugs

2. With the plugs out, and with the choke and throttle open, pull her over a few times to clean her out.

3. Reinstall the plugs

4. Open the throttle and shoot some ether into the carb, then quickly close the throttle. Hit the choke and pull like mad.

5. If it fires but doesn't go, repeat the above. If it does nothing, get back to me for you have a different and serious problem.

Jeff
 
fastjeff said:
Have you tried starting fluid (ether)? You'll get a bunch of guff on that being "dangerous" to your engine (it contains no oil) but it isn't when the motor already has lots of oil inside; and that's the problem--it's flooded with oil.

I've seen many a stubborn Merc 110, so try this:

1. Plug and clean the plugs

2. With the plugs out, and with the choke and throttle open, pull her over a few times to clean her out.

3. Reinstall the plugs

4. Open the throttle and shoot some ether into the carb, then quickly close the throttle. Hit the choke and pull like mad.

5. If it fires but doesn't go, repeat the above. If it does nothing, get back to me for you have a different and serious problem.

Jeff
Click to expand...

Thanks Jeff,
I did what you suggested. It fired (spit and sputtered, smoke) but could not get it started.
I pulled until I pulled the rope out.

I also replaced the float seat. And now it seem it wants to go when at full thottle / choke on then off.

Any suggestions?
 
Give it more choke when it sputters...they like lots of fuel when cold...hold the choke in for 10 secs. Then hit the key to start. That's what I have to do to start my 2002 115 hp.
 
Question: Before the rope broke, did it fight you tremendously when you pulled the rope, quicking back violently as if the spark was way advanced?

Jeff

PS: This is aserious question with an answer that might help you.
 
Check spark !------------" good spark " is considered to be able to jump a gap of 1/4" or better.----------If it will not do that then magneto needs work.
 
If it will not jump 1/4 " then the magneto needs repair.-------------You say you cleaned the points already ( absolutely must be clean ) no grease oil or dirt on them is tolerated.
 
That's not a magneto--it's the infamous Phase Maker ignition system. I suggest you try the super wide gap plug test to see if there's enough spark there for it to run: Take a junk plug and open the gap as far as possible, then see if the spark still jumps.

Jeff
 
RicknDee Huntington said:
I can not get my Mercury 110 to start
So far I checked :
1. Compression > then 100 psi
2. Cleaned Points
3. Checked Coils (both 532 ohms)
4. Checked the wiring with the diagram (switched wires on coil 1 to match diagram)
5. Cleaned carburetor - new bottom needle, cleaned filter and pump.
6. Checked top dead center on #1 cylinder, mark (one of the 2 marks) line up with factor markings

I have a good spark on both cylinders

I am currently think this may be a carb problem / plugs are normally wet

I have been getting a little bit of a spud-er every once in a while

I will be grateful for any suggestions
Click to expand...
I have a question. I have a mercury 110 9.8hp 1980’s and it was running great and all of a sudden it bogged and went to a real small idle and died. Sold start after, broke rope, replaced. Now won’t start. When I squeeze the bulb gas runs out of the carb. I was thinking that the fuel line collapsed bc I just bought the motor and it came with a gray fuel line which I heard bad stuff about. Pls help thanks!
 
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