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1976 Mercury 110 9.8 2 stroke - Won’t Start

C

Cajones

New member
Hello All,

So I’ve been through quite the process over the last few months. I bought a 14’ boat with the above mentioned motor as well as a trolling motor. During the outboard motor test, it was a bit of a hard start, but started nonetheless. However, I noticed the water stream wasn’t coming through, so I ordered and replaced the impeller. Good right? No...

I could not get it start again. During my attempts, I guess I got a little overzealous and damaged the pull starter/recoil spring. I attempted to removed it but could not get it out. I managed to locate some parts and just replaced the entire starter housing...once that was installed, it would turn over, but I could never get it to start. I removed the carburetor, cleaned and secured every thing. Still to No avail. Does anyone have any idea what I should do next? I can’t find any videos for these problems with this particular motor. I’m at a bit of a loss...Anything will help. Thanks in advance.
 
Test compression.----Check for good spark.----Now good spark on these is considered to be able to jump a gap of 3.8" ( 1 cm ) on a test device.
 
I got banned from a Merc site for saying this, but what the hell....

Merc added a throttle stop to those motors that keeps them from over-reving on start up. (I guess they thought ham-fisted morons would over rev them motor in neutral.) And, to keep those naughty boys from shifting it into gear and opening the throttle, to get away from that fool stop, they added a dingus that locks the recoil starter except in neutral--they weren't taking any chances!


Anyways. this stop is a bit too aggressive when the motor gets a bit old and won't allow enough throttle to get them going--and Mercs love a bunch of throttle to get going.

My usual solution is to remove and toss that stop out. (It's located near the bottom of the carb--a 5/16 wrench as I recall).

Now (and this is what got me banned) you don't just crank the throttle wide open and pull the cord, not that the motor will zing its way to 9 gazillion rpm in a second--its heavy flywheel slows reving up. You simply add a bit more throttle and yank away.

Does wonders for starting, especially if you accidentally flooded the motor.

Jeff

PS: If I get banned again, sure was nice e-talking with you folks!
 
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The motor is 45 years old.-----Why does it suddenly need this modification.----The owner should do some simple trouble shooting and repair accordingly.
 
If the comp. and spark are OK then maybe the starting procedure isn't being followed 1: Pump fuel line bulb until hard 2: Pull choke out all the way, 3: Make sure it's in neutral and advance throttle to start position 4: Pull cord 5: If it starts push in choke. A quick way to see if fuel is getting into carb is to tilt the motor onto its full tilt position and pump the ball - fuel should flow out of the carb.
 
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racerone said:
Test compression.----Check for good spark.----Now good spark on these is considered to be able to jump a gap of 3.8" ( 1 cm ) on a test device.
Click to expand...


Finally did the compression test...ended up getting one from harbor freight. Both cylinders tested around 50 psi ��. There’s no obvious leaks around the gasket or anywhere really.

BUT...I’ve read to get a true test of compression the engine needs to be started and be warm. Obviously the problem with that is...it won’t start. I have two new spark plugs coming in...i don’t think that’s the problem, but what the hell. Any insight as how to proceed?
 
Quicksilver said:
If the comp. and spark are OK then maybe the starting procedure isn't being followed 1: Pump fuel line bulb until hard 2: Pull choke out all the way, 3: Make sure it's in neutral and advance throttle to start position 4: Pull cord 5: If it starts push in choke. A quick way to see if fuel is getting into carb is to tilt the motor onto its full tilt position and pump the ball - fuel should flow out of the carb.
Click to expand...


The compression was approximately 50 psi per cylinder, so that’s a bit low. All the starting procedures were followed. I’m quasi OCD with that stuff, so ����*♂️
 
fastjeff said:
I got banned from a Merc site for saying this, but what the hell....

Merc added a throttle stop to those motors that keeps them from over-reving on start up. (I guess they thought ham-fisted morons would over rev them motor in neutral.) And, to keep those naughty boys from shifting it into gear and opening the throttle, to get away from that fool stop, they added a dingus that locks the recoil starter except in neutral--they weren't taking any chances!


Anyways. this stop is a bit too aggressive when the motor gets a bit old and won't allow enough throttle to get them going--and Mercs love a bunch of throttle to get going.

My usual solution is to remove and toss that stop out. (It's located near the bottom of the carb--a 5/16 wrench as I recall).

Now (and this is what got me banned) you don't just crank the throttle wide open and pull the cord, not that the motor will zing its way to 9 gazillion rpm in a second--its heavy flywheel slows reving up. You simply add a bit more throttle and yank away.

Does wonders for starting, especially if you accidentally flooded the motor.

Jeff

PS: If I get banned again, sure was nice e-talking with you folks!
Click to expand...


Thanks Jeff. If all else fails (and maybe even if it doesn’t ��) I might remove that stop. I’m not super experienced on this but my compression test was around 50 psi per cylinder, so not sure where to proceed.
 
FYI...I definitely appreciate all the comments...keep them coming!!! ��
I actually didn’t expect anyone to reply...����
 
Only 50 psi is way too low--unless the rings are stuck. A can of Power Tune from Merc might be worth trying.

Jeff
 
fastjeff said:
Only 50 psi is way too low--unless the rings are stuck. A can of Power Tune from Merc might be worth trying.

Jeff
Click to expand...


My only issue is that I’ve seen many compression testers have wildly different results. The compression tester I bought had fairly good reviews, but who really knows. Hell, maybe I did something wrong during the compression test ����*♂️
 
On the starboard side of the motor you will find a cover.----About 1-1/2" X 4" held on with 3 screws.-----Remove that cover and have a look at pistons and rings.
 
racerone said:
On the starboard side of the motor you will find a cover.----About 1-1/2" X 4" held on with 3 screws.-----Remove that cover and have a look at pistons and rings.
Click to expand...


youre talking about this right? Just a little worried about damaging the gasket. BCB776E0-D81D-4DEC-B709-4025D21E5EF1.jpg
 
racerone said:
On the starboard side of the motor you will find a cover.----About 1-1/2" X 4" held on with 3 screws.-----Remove that cover and have a look at pistons and rings.
Click to expand...


i don’t really see any OBVIOUS damage, just a little gunky. There looks to be some flaking on the outer casing and residue on the other part. What do you think? When I turn the flywheel, the pistons move freely and I really don’t see any problems or obstructions. Here’s a few pictures...

24F22AC3-7E47-4D24-B2D7-A4F6157CB5B6.jpegDC5712FB-AC46-4BAC-B036-8D04046DBB3B.jpeg9CE0FE41-06F6-4B6C-AFC3-BE8ADFCCDC7D.jpegBA2E74E7-E0A2-492B-9007-FF5A0F83687B.jpeg
 
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