Force 120 outboard won't start when warm

lakemerwinlarry

Recruit
Joined
Mar 29, 2015
Messages
3
Hi everyone,

I bought a 1998 Bayliner 1800 with a Force 120HP outboard a couple months ago. When we test drove the boat, it ran great, no problems.
I took the boat up to the lake the next week and we were on the water the whole weekend with no issues.

Same thing the weekend after that. It was my 5th time out on this boat. We ran all day, drift fishing - starting and stopping the motor several times throughout the day.
Got the boat to the dock, and it wouldn't start to pull it onto the trailer. Smelled of gas like it was flooded too.
Thank god there was nobody at the launch - we must have looked like fools pulling the boat onto the trailer with a ROPE!

So yesterday we put her in the water again - she started right up on the second crank. She ran great all day, but I noticed that she was smoking (blue smoke) a bit more than normal. Because I was a tad bit gunshy from the weekend before, I didn't shut it off, we ran around the lake for a bit - fished some - then headed back to the ramp about 2 hours later.

I shut it down, went and got the trailer, came back - won't start! Waited 10 minutes, still won't start.
again - had to PULL the boat onto the trailer with a rope.

This time after cranking and cranking (and not starting) I noticed a heavy gas smell, like it was flooded. when I tilted the motor up to pull it onto the trailer, I noticed feel dripping out of it.

Gas used - 87 Octane with regular marine 2-stoke oil at 50:1 mix.

This is pretty frustrating. Like I said, I'm new to boating and know almost nothing about this outboard besides what I have read already.
Does this boat need professional help? I'm pretty mechanically inclined and can fix it if it's something minor.

It would be nice to work out these bugs before summer comes and the weather warms up and the kids want to get on the water every weekend!
 

SkiDad

Lieutenant Commander
Joined
Jul 18, 2010
Messages
1,518
what about starting it up in fast idle - pull out throttle base towards you with left hand and then push forward with rig
ht hand.

Sounds like fouled spark plugs. Have you cleaned or replaced them. They should be NKG BUH. Double check this bc your motor is newer and I might be wrong on that.

Also check your idle speed. Idle adjustment is at the bottom of the tower and not up near the flywheel.
 
Last edited:

Jiggz

Captain
Joined
Oct 23, 2009
Messages
3,817
I'm concerned that after the first time it would not start while warm, it could be that you lose a cylinder or one cylinder quit on firing. This could be due to some electrical problem or it could also be mechanical. I'm not really sure how experienced you are with 2 cycle engines but for the inexperienced, it is very hard to discern especially with 4 cylinder engines to discern when one cylinder is not firing. As suggested start with the plugs to make sure they are not worn out and fouled. Replace them as required. Second, double check no cylinder is misfiring or not firing. You can do the plug wire pull test to listen to change in engine tone but make sure you do it very quickly for each plug wire to avoid damaging cd modules. If you find one cylinder not firing, you might want to do a compression test on the engine.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
Try tilting the motor all the way up and then turn it over.
As soon as it pops, starts, drop it and then start.
Might work, might not.
Some time the additives in the fuel swell the rubber and the float sticks.?? Or maybe not!!
 

HydroGeek

Cadet
Joined
Feb 10, 2015
Messages
16
Next time this happens, check to make sure that you have spark. Keep a spare plug with you, and a beefy alligator / test clip lead. Pull each of the plug wires, attach it to the spare plug and ground the body using the test lead. You could hold the plug against the engine to ground it, but you risk not getting a good ground. Check each plug for spark. If no spark, check your stator leads for correct resistance.

This will at least tell you if this might be electrical or fuel related.

Can you duplicate this in your driveway with water muffs on the engine? Can you get it hot enough that way to make it fail?

Sorry for the trouble. I have the opposite problem right now.... mine won't start when cold. All things considered I'd rather have my problem.

Good luck!
 

lakemerwinlarry

Recruit
Joined
Mar 29, 2015
Messages
3
Finally got back out on the lake today. I replaced the plugs and put the boat in the water. As usual, the motor started on the first pull. ran great all day. Not as much smoke as there was the last time out. Ran and trolled around for about an hour and a half.
Got it back to the dock, shut it down. Again, wouldn't start... GRRRR.
I pushed the throttle only button and boom - she started up right away.

One of the guys at the dock said I may have mixed my gas a little too rich.

At least I know I can get it started...

Thanks for the suggestions everyone. I'm looking forward to being on the water this summer!
 

Jiggz

Captain
Joined
Oct 23, 2009
Messages
3,817
Normally, with just about all two stroke engines when warm will start on the first try even without throttling or choking. I'm still wondering if your motor is actually only running on 3 cylinders. And the main reason could be bad or broken reed. I wish you can post a video of it idling so we can actually see and hear it.
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,657
You could also be down a cylinder when hot, due to a failing coil. It gets hot and will stop working.
Although it will usually restart.


If you are really experiencing a flooded condition, it could be the fuel pump diaphragm.

They get ildm develop holes or tears, and leak fuel directly into the crancase and flood out 1 or 2 cylinders.

Fuel pump diaphragm should be on your regular maintenance list, about every 5 years or so.

Could be you are still running the original diapagm, which should be replaced. $13.


http://www.iboats.com/mall/partfind...gd_poid=112445&gd_row=45&session_id=130665444
 
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