Advice on Honda 15 HP 4 stroke

[Tomcat]

I have a Honda 15 HP four stroke short shaft outboard purchased new in 2007. During two week long trips in 2007, the motor performed flawlessly for my application (90% of the time I back troll for walleye). Last fall, dealer’s mechanic did 20 hour maintenance routine as well as the winterization.

 

First 08 use of this outboard was a recent week of walleye fishing (90 % back trolling as usual) at a remote location four hours from nowhere. Unfortunately, while the motor ran great at ½ to ¾ WOT going from A to B, it continually stalled during back trolling. Although the motor was easy to restart, a cloud of blue smoke always accompanied the restart. I was reluctant to attempt fixes at water’s edge because, firstly, I’m no mechanic, and secondly, one can’t easily get at spark plugs or the oil dipstick without removing a bunch of screws. I was also 16 miles (by water) from my truck.

 

Once home, I checked both spark plugs. Both plugs were dry and looked identical. Both were dark chocolate brown to black in colour. When I checked the oil reservoir, the oil level was almost an inch above the full mark.

 

Could the high oil level in the reservoir be responsible for the problems experienced?

 

Might it be beneficial to switch to a hotter plug? I’ve read that prolonged idling or continuous low-speed driving (i.e. back trolling) may keep spark plugs from reaching their optimum operating temperature.

 

Does anyone have other suggestions/recommendations?

 

Thanks in advance.

[Fisherman]

Well Tomcat, take a 20 pound frozen carp, go to the dealer/mechanic that did the servicing and give him 20 smacks upside the head with said frozen carp and tell the dumb poop to pay attention how much oil goes into the crankcase. Hopefully no other damage has been done by overfilling. Pull the drain plug at the rear of the motor case(just underneath the outside of the motor hood), I believe it's a 12mm hex head bolt. Drain about a cup of oil or until the dipstick shows no more than full. You should get another set of plugs too. That should solve the problem. It's not hard to winterize those motors, you can do it yourself with a bit of guidance. Good luck. Dpon't worry about trolling at idle with those motors, mine probably spends 95% of its time at idle trolling in Georgian Bay, 12 years, second set of plugs, absolutely no fouling.

Edited August 24, 2008 by Fisherman

[vance]

Some 4 strokes have tendency to make oil. Check out this link from Iboats http://forums.iboats.com/showthread.php?t=158085 I think it shows where the extra oil comes from.

 

vance

[Wild]

Change your oil and note the color and if any water is present. concerning your plugs there is no need to change them and a hotter plug if available might promote detonation at full throttle and that could cause permanent damage. If your plugs are in good shape with sharp edges just clean them with carb cleaner and use air to blow out any debris.

 

The dark color of the plugs is an indication that the engine fuel mixture may be rich and stalling at low speed would back that up.

 

The best thing you could do when this 4 stroke is broken in would be to use Royal Purple synthetic oil it's superior in every way for this engine with better protection, performance ,fuel economy, and the internals will be so much cleaner.

[Garyv]

Well Tomcat, take a 20 pound frozen carp, go to the dealer/mechanic that did the servicing and give him 20 smacks upside the head with said frozen carp and tell the dumb poop to pay attention how much oil goes into the crankcase. Hopefully no other damage has been done by overfilling. Pull the drain plug at the rear of the motor case(just underneath the outside of the motor hood), I believe it's a 12mm hex head bolt. Drain about a cup of oil or until the dipstick shows no more than full. You should get another set of plugs too. That should solve the problem. It's not hard to winterize those motors, you can do it yourself with a bit of guidance. Good luck. Don't worry about trolling at idle with those motors, mine probably spends 95% of its time at idle trolling in Georgian Bay, 12 years, second set of plugs, absolutely no fouling.

 

 

I 100% agree with the above...in fact it's what I do my own servicing on my Honda 5, 9.9 and 50 Easy to do and the right amount of oil goes in. Remember when changing the filter you will add a a bit more oil than required if you don't change it. Just watch the dipstick and if you don't run it at the oil change check the stick after you finally run the motor.

[glen]

The best thing to do is to follow the manual that came with the motor.

 

When i change my oil i measure out the amount as per the manual. I think it is 1.3L with a filter change.

 

Also never lay that motor down on the wrong side.

[holdfast]

I have an older Honda four stroke that ran flawlessly till this year. I just got it out of the shop since July 1st long weekend believe it or not. What happened is a magnet fell out and jammed the motor so I had to change the flywheel. 1 hour labour but a 375 dollar part. Ouch

 

Now for you. I had my engine do the same thing. Puff of smoke and half power. After checking the oil I decided to change a spark plug. I was lucky and picked the right one as no problems afterwards. Here's what I learned, I carry a set of tools and now have two new spark plugs as backup instead of one.

 

As far as winterization, Ill disconnect the hose and run the engine till it runs out of gas. There is also a screw in the Engine to drain the carb. Its in the Owners manual. Ill change the oil and the lower case oil, then I store it in my heated basement. Ive only changed the fuel filter once in 3 years and it was only a preventive thing.

[Tomcat]

Here's a follow-up to my post about the constant stalling problem I experienced while back trolling this summer with my 2007 Honda 15 HP four stroke outboard.

 

Took my Honda back to the dealer. First thing they did was to determine whether idling rpms (after warmup) were within spec. Idling rpms were 200 rpms too low. After adjustment of the idling rpms to 950 (spec says 900 plus or minus 50 rpms), my outboard idled without even a hiccup for 45 minutes while in reverse in the water tank. I asked the tech to lower idling rpms 200 rpms and rerun idling in reverse test in water tank. Within a couple of minutes, you could hear the tell tale engine shutter that prefaces a stall. Sure enough within 5 minutes, the engine stalled. During this 5 minute period, the engine rpms kept degrading (from a start of 700 to about 530 at stall). This degradation of the rpms remains unexplained. Anyway, suffice to say that I'm now satisfied that the improperly set rpms during 20 hour maintenance service were the cause of my stalling problems. I've reset idling rpms to 850 (lower limit of spec) to keep backtrolling speed to a minimum (I can adjust if necessary). Dealer didn't charge me a cent for the service call - I didn't even have to threaten to hit the mechanic with a 20 pound frozen carp.

[Raf]

As far as winterization, Ill disconnect the hose and run the engine till it runs out of gas. There is also a screw in the Engine to drain the carb.

 

Hey holdfast, I used to think disconnecting the hose is a good idea to drain the fuel however, I've since been told that the fuel pump relies on gas as lubrication and you could burn it out draining the engine of fuel this way. The screws on the carbs are the way to go.

[fishdawg]

good point Raf

 

just add stabilizer & fuel line-antifreeze to your tank and run it through during your final couple trips of the season whenever that may be, then top the tank up for storage

[holdfast]

Hey holdfast, I used to think disconnecting the hose is a good idea to drain the fuel however, I've since been told that the fuel pump relies on gas as lubrication and you could burn it out draining the engine of fuel this way. The screws on the carbs are the way to go.

Thanks for the Tip, point is taken