Merc 115 Tower of Power Won't start

[timo4001]

I recently bought a 1986 Merc 115 on an 18 ft tri hull. When I looked at the boat, it started right up, went into forward and reverse just fine, so for short money I bought it. The boat had been sitting covered for a few years, so I knew I would need to do some maintenance when I got it home. When I got home it will not start....it cranks fine. I replaced the impeller, 4 of the 6 spark plugs (2 were helio coiled from a previous owner, so I figured I would replace them later). Pulled the carbs off and apart, chem dipped them, (got the 3 rebuild kits) re installed and set the jets to where they were when I took them apart. I am using fresh 93 (50:1) in a separate tank...still no joy. I have spark on all 6, compression is 110 on the 4 cylinders that aren't helio coiled. Obviously I have squeezed the fuel bulb till its good and hard, and the bowls are getting filled. Fuel filter is new and I can hear the choke clicking when I push in on the ignition switch.
What am I missing? Something simple I hope. Any help would be appreciated.

 

[ThomW]

Is there a safety lanyard or kill switch that is not connected?

 

[racerone]

Give it lots of throttle in neutral.----Push key in and hold it in while cranking it over.

 

[timo4001]

Is there a safety lanyard or kill switch that is not connected?

No, I don't believe so. Also, if there was, I wouldn't be getting spark.

 

[timo4001]

Give it lots of throttle in neutral.----Push key in and hold it in while cranking it over.

Tried that, no luck yet.

 

[ThomW]

Did you try starting it at home prior to the work you did and it wouldn't start, or after?

 

[timo4001]

Did you try starting it at home prior to the work you did and it wouldn't start, or after?

I tried it before I began the work. Wouldn't start. I figured the ride home probably shook up crap in the tank and trying to start it after the ride probably got junk in the carbs....hence the rebuild.

 

[racerone]

And so the trouble and the trouble shooting starts.----Charge the battery, then load test the battery ( even if new )-----Take starter apart for inspection , ohm test on armature and perhaps new brushes.-----Test for spark ( sparkplugs still in the block ) and see if you have spark.----Spark must jump a gap of 3/8" or more.

 

[timo4001]

And so the trouble and the trouble shooting starts.----Charge the battery, then load test the battery ( even if new )-----Take starter apart for inspection , ohm test on armature and perhaps new brushes.-----Test for spark ( sparkplugs still in the block ) and see if you have spark.----Spark must jump a gap of 3/8" or more.

Batteries check out fine. One is new and load tested fine, the other is a deep cycle less than a year old I keep on a trickle for my camper. Starter is not giving me issues, spinning fine and strong. Spark is strong on all 6 cylinders. If it had a distributer, I would surmise a timing issue.....but it doesn't.

 

[racerone]

Well ----Then it should start right up.-----Is gas line connected ?----Primed the bulb till hard ?

 

[timo4001]

Well ----Then it should start right up.-----Is gas line connected ?----Primed the bulb till hard ?

Yes...it should start right up. Fuel lines good, primed till hard. That's why I'm stumped. Compression good, fresh fuel, rebuilt barbs etc.

 

[Chris1956]

It is worth it to check the timing. Set the throttle to a point where the carbs are ready to open, but still closed. Remove prop. Turn ignition on and connect timing light to top spark plug wire.

Jumper starter solenoid and read timing at decal. Timing should be 0-8* ATDC.

 

[timo4001]

It is worth it to check the timing. Set the throttle to a point where the carbs are ready to open, but still closed. Remove prop. Turn ignition on and connect timing light to top spark plug wire.

Jumper starter solenoid and read timing at decal. Timing should be 0-8* ATDC.

Of course this boat is at my camp....and 200 miles away from my timing light and the 2 rollaways in my garage. Brought what I thought I would need for tools of course...and a timing light was not on the list....go figure. That being said, the light might not do too much good for this distributor-less ignition. I need to get a gauge to measure TDC of #1 cylinder, according to the repair manual. Still, since it ran when I bought it, and two hours later when I got it back to my camp it didn't, I figured something besides timing. But...that's why I am asking for help. I'll check timing next though. Thanks!

 

[Chris1956]

If you want to check the timing, a timing light is necessary. I do agree that the would not normally change, but you have ruled out the other stuff...a motor needs spark, fuel and compression to run. You say you have those, so timing is logical to check.

Maybe you inadvertently changed the timing by hitting the trigger linkage? Maybe you changed some of the screws on the throttle arm? Those control timing.

 

[timo4001]

If you want to check the timing, a timing light is necessary. I do agree that the would not normally change, but you have ruled out the other stuff...a motor needs spark, fuel and compression to run. You say you have those, so timing is logical to check.

Maybe you inadvertently changed the timing by hitting the trigger linkage? Maybe you changed some of the screws on the throttle arm? Those control timing.

Yup, could be. I didn't touch the throttle arm, but you never know. I hate to buy another timing light up here.....haven't used mine in years (just like my dwell meter). So I think I will call it a day for today, have a beer and check on the throttle arm tomorrow. Thanks again.

 

[sludgeguy68]

FWIW, my tower needs a lot of fuel to start, even after a full rebuild. Trim all the way in, squeeze fuel past the needles, full throttle in neutral and choke. Gotta be johnny on the spot to pull it back when she goes, but it works. Could try squirting some premix in the carb throats? But yeah a timing light would be next step.

 

[Chris1956]

You didn't remove the outer flywheel by any chance? Those get reinstalled wrong all the time, which can play havoc with the timing.

Spray some 50::1 fuel into the carbs, pull up on the manual choke knob. cold start all the way up, and crank her.

 

[Faztbullet]

Reinstalling flywheel wrong will not effect static or running timing, just marks in wrong location

 

[katch_me]

This is something I came across on my 90. The starter gear was stripped. It sounded like it was cranking. But it really wasn’t. I put a piece of tape on the flywheel to clearly see how fast it spins. For me it a pinned a bit, then stopped, then spinner again. Never can start like that.

 

[jheron]

FWIW, my tower needs a lot of fuel to start, even after a full rebuild. Trim all the way in, squeeze fuel past the needles, full throttle in neutral and choke. Gotta be johnny on the spot to pull it back when she goes, but it works. Could try squirting some premix in the carb throats? But yeah a timing light would be next step.

This.
Good luck!
Jon