1986 Mercury 9.8 110 outboard

[Kissdude]

I was wondering if someone could help me please. I have a 1986, 110, 9.8 mercury outboard. It’s been sitting a very long time but I have spark, carburetor has been soaked in gunk and completely cleaned but I still have no wet spark plugs. Plugs have been replaced as well. Any help here would be appreciated.

 

[Scott Danforth]

86 should be a 9.9/15, where the prior 7.5/9.8 series ended in 1985

Did you do a compression test? Issues with the reed valves?

Did you set the float correctly?
Did you go thru the fuel pump?

 

[Kissdude]

I’m not sure why they say the reeds are behind the carb on this one, I believe they are under the flywheel. Upon looking they look like not sitting flat but trying to find the manual to look this up.

 

[Kissdude]

I’m having troubles locating my manual. It’s a 9.8 110 Mercury, model number. 7151133 any help would be appreciated

 

[airshot]

If compression is good, then do a rebuild on the carb with a factory rebuild kit as it will give you all the specs for setting it up. Just cleaning rarely works in my experience, you need those new seats and gaskets. Also a thorough take down to clean all those tiny passages. If compression is good, you have spark and fuel, it will run.

 

[jimmbo]

Shows up as a 1980 - 1981 Canadian 9.8

https://www.marineengine.com/parts/mercury-outboard-parts/98/7127388-up-can

The Reeds on a Block that doubles as the Center Crankshaft Bearing

 

[Kissdude]

If compression is good, then do a rebuild on the carb with a factory rebuild kit as it will give you all the specs for setting it up. Just cleaning rarely works in my experience, you need those new seats and gaskets. Also a thorough take down to clean all those tiny passages. If compression is good, you have spark and fuel, it will run.

I took the carb apart, soaked it and then cleaned it all up, motor doesn’t even try to start. I have a bowl full of fuel, compression and spark, plugs are still dry tho so no idea. Was thinking maybe the reeds but like I said I don’t see them behind the carb.

 

[Kissdude]

Shows up as a 1980 - 1981 Canadian 9.8

https://www.marineengine.com/parts/mercury-outboard-parts/98/7127388-up-can

The Reeds on a Block that doubles as the Center Crankshaft Bearing

Ah ok then. I took the flywheel, trigger and bearing housing off, looked inside and (if I know what the reeds at) they don’t sit flat. Any ideas?

 

[jimmbo]

https://www.marineengine.com/parts/mercury-outboard-parts/98/7127388-up-can/crankshaft-pistons-and-connecting-rods

The Reeds are #11

Have you tried spraying a bit of Premix into the Carb Throat, to see if it fires?
You say it has spark. Is the Spark strong enough to jump a 3/8" Gap?

 

[Kissdude]

I have tried spraying premix into the carb along with ether, I know that’s bad but nothing happens at all. I’ve also been using an online spark tester and I do get spark.

 

[jimmbo]

A spark tester like this? Don't waste your time or money on ones that are in a Bulb



Don't spray Ether into a 2 Stroke, not a good idea as it ignites by compression, and there is Compression in the Crankcase too. It also can wash away Oil, very critical for the Bearings

Maybe try a few drops of Premix into the Sparkplug holes, and see if it lights

 

[Kissdude]

I have been using a tester with a bulb. What do I have to look at for better spark?

 

[Kissdude]

https://www.marineengine.com/parts/mercury-outboard-parts/98/7127388-up-can/crankshaft-pistons-and-connecting-rods

The Reeds are #11

Have you tried spraying a bit of Premix into the Carb Throat, to see if it fires?
You say it has spark. Is the Spark strong enough to jump a 3/8" Gap?

so looking down the crankshaft, the reeds must be almost touching the round pieces correct? and if they look like bending up, what does that mean please?

 

[jimmbo]

A tester like the one I post a pic of, is adjustable, and puts the Ignition System to the Test. They are available on Amazon, and Evil Bay. A very large Gap is required because not much Voltage is required to jump a 0.030" Gap at Atmospheric Pressure, in the Combustion Chamber at much higher Pressure, a lot more Voltage needed. That 0.030" Gap on the Plug is now closer to a 5/16" Gap at Atmospheric Pressure.
Electricity is a creature with a One Track Mind, connect to Ground. And it doesn't care how it gets to do so, and will always pick the Easiest Path, so any weakness in the Wire Insulation, cracks in the Coil Housings or the Plug Ceramic Insulator, will offer a lesser Resistance than the Plug Gap

There are Reed Stops(part #12 on the Parts List) above the Reeds. They limit the Travel of the Reed, and they are Curved away from the Block, so maybe you are seeing the Stops.

 

[Kissdude]

That makes a lot of sense, thank you. I must be seeing the stops and the reeds are probably good then. I haven't learned much about reeds yet nut probably should. I forgot that I ordered new coils last fall along with a tester like the one you showed here and maybe try the new coils to see if I can get better spark.
Thanks again

 

[airshot]

I took the carb apart, soaked it and then cleaned it all up, motor doesn’t even try to start. I have a bowl full of fuel, compression and spark, plugs are still dry tho so no idea. Was thinking maybe the reeds but like I said I don’t see them behind the carb.

If the plugs are dry, the carb is not letting fuel in, you probably have a blockage that you missed, or compression is low enough to not draw the fuel in.

 

[Kissdude]

So I went out and tried this morning and pulled her a few times and no start but now, the pull start came apart and feels like I have no compression like I broke something? there is little resistance when I turn the shaft and propeller moves when I do. The pistons still go up and down. Any idea of what might have happened?

 

[jimmbo]

The Recoil may have failed. When you pull the Cord, does the Flywheel turn? Or does the Cord just pull out, and then goes back in?
Have you ever done a Compression Test on this motor?
If yes, what were the Numbers?
If no, do it and post the Numbers

 

[Kissdude]

The Recoil may have failed. When you pull the Cord, does the Flywheel turn? Or does the Cord just pull out, and then goes back in?
Have you ever done a Compression Test on this motor?
If yes, what were the Numbers?
If no, do it and post the Numbers

ya the recoil failed for some dumb reason and doesn't retract but now my main concern is that I had about 100 compression before but now if I turn the flywheel by hand it turns with very little resistance. The prop turns while i do this and pistons move in and out.

 

[jimmbo]

The Recoil: Either the Spring has snapped, or something has jammed it, preventing it to retract. A bit of Troubleshooting needed. A Word of Warning, if the Spring is not Broken, it will be storing a lot of Energy, and can be VERY Dangerous to work on.
The Link I provided in Post #6, will take you to a Menu, an Exploded view of the Recoil is in there
The Motor: Are the Plugs installed, Properly(Seated with Gasket, not Cross Threaded)? A Compression Test is still needed. Not easy right now, and if I recall, there is no Provision for a knotted Rope to be used when the Recoil is out of commission. Don't even think of using a Drill to spin the Crankshaft, as that may overtighten the Flywheel Nut, and ruin the Flywheel