Kicker Motor problems, Mercury 8HP

[Mike Carey]

I just got back from fishing Merwin and had some weird kicker motor troubles. I have an 8HP Mercyry two-stroke. It's around 7-8 years old. Generally runs pretty good, likes to hiccup from time to time...

The problem I had was the motor starting running really rough, wanted to die which I averted by giving it a biot of gas, then it started doing it more. I opened up the choke and it ran good for a bit, then started up again. It final just died. I could not get it to turn over. I let it rest, nadda. Right before it died it had a burst of whitish bubbles from the prop exhaust. Nothing floating on the water, but it was odd. I figured maybe a fuel pump had died, IDK, not a motor guy. Anyway, a day later I tried to start it and it fired right up. I ran it about ten minutes at full throttle to get back to the boat launch so did not try trolling at low speed with it.

Any ideas as to what may be going on?

[scraig1962]

Since your motor ran better when air was choked off, it sounds like a fuel problem, but im no expert. Before throwing money and parts at it I would check the obvious first which would be spark and fuel. Pull the plugs and use a spark gap tester set at 3/8" and see if theres a bright blue spark on each plug while operating starter. Another way is to unscrew the plugs from the block, plug them into the coil wire and hold the plug about 3/8" away from the block with gloves while operating the starter. If the spark is weak or doesn't jump the gap then you have ignition problems. In the case of my old mercury 7.5 hp, I had a bad coil which was causing weak spark and poor performance then a bad ignition module which caused it to not spark/start. Before buying a rebuild kit for the fuel pump, i would pull the carb and do a good cleaning with compressed air and carb cleaner since its fairly easy and you shouldnt need parts to clean it.

[Mike Carey]

Thanks, now if I just knew half of what you said.

I'll have to do some researching...

[Idstud]

When was the last time you had the fuel filter changed? There should be one before the carburetor.

[ridgeratt]

Remove the hood there is a filter in the gas line. It should unscrew and then you can dump out any water that has gotten in there. Not sure if that is it but just a Bad guess on my part!

[hewesfisher]

Mike - Since your kicker is a two-stroke, do you run it off a separate tank or same tank as your main (don't know what you have for the main)? Do you always use fresh, non-ethanol, 87 octane? Do you ever mix non-ethanol with ethanol? Have you ever changed the fuel lines and bulb from tank to motor? When was the water pump impeller last changed?

[Mike Carey]

All good questions, last tune up was two years ago. I guess it's time...

[Bodofish]

The white goopy stuff from the exhaust is quiet normal for an engine (2C) that runs at low speed a lot. Its just unburned 2 cycle oil and water. Toss in a couple plugs, change any filters then do what ever it takes to make it run and pump a couple gallons of seafoamed fuel through it. Merc and BRP both make an aerosol that's used for cleaning out the built up oil and carbon. In both cases run it full throttle and spray it in the carb and it will amaze you what comes out. Don't do it on the water, they'll be calling you Mike Valdez....... I've got to do it to my old Johnson 9.9 every couple years.

[hewesfisher]

The white goopy stuff from the exhaust is quiet normal for an engine (2C) that runs at low speed a lot. Its just unburned 2 cycle oil and water. Toss in a couple plugs, change any filters then do what ever it takes to make it run and pump a couple gallons of seafoamed fuel through it. Merc and BRP both make an aerosol that's used for cleaning out the built up oil and carbon. In both cases run it full throttle and spray it in the carb and it will amaze you what comes out. Don't do it on the water, they'll be calling you Mike Valdez....... I've got to do it to my old Johnson 9.9 every couple years.

^^^^ This!

One thing I always do with my kicker is run it WOT for at least 5mins after every trolling session. 4-strokes will load up if always run at low speeds (mine spends 99% of its running time at low speeds) and 2-strokes are far more susceptible to plug fouling.

Merc's aerosol is called Power Tune. Once you get the motor cleaned out, Quickleen (1 oz to 5gals) in every tank will keep it that way.

[ResQ]

Quite honestly, it sounds exactly like what my Nissan 8 hp did a while back. Took it to Toms Outboard and it was the carburetor. He said it was more than likely from the ethanol pulling in moisture, but the carb was gummed up. He cleaned it with their sonic clean thing and it was 100% like new. But mine was doing the same thing yours was/is. Even ran better half choked. Frustrating as all get out! I was even using treated fuel. It was like 200$ for the tear apart and cleaning.

[duffy]

Sounds like either water in the gas or ethanol phase separation or both. If it's old gas drain and get new non ethanol. If you've never had ethanol gas then it's probably water.

Simple things to do that help enjoy playtime:

Always use fresh gas preferably non ethanol. Either filter your fuel and keep it clean and for god's sake take a look in the empty can once in a while. You wouldn't believe the crap and water I've seen in peoples gas cans.

When you get to the dock and any time the engine is going to set for some time disconnect the fuel line and let the engine run out. Or during a WOT run on the lake pull the line and let it run out which is a bit better. (pulls more fuel out of the bowl) I did this on my first boat engine and the carb was still spotless after 25 years.

Open up the trolling motors and run them at high speed. This heats them up more, burns off deposits in the cylinders and plugs and makes fuel and air flow through all of the carb passages. Also helps boil off moisture if you've gotten water in the fuel.
Be careful adding additives like seafoam. Add the suggested amounts and don't do the "if a littles good mores better" philosophy because it can build up. Most additives don't burn the same as gas and can cause an engine to run lean making it hard to diagnose problems.
Just my 2 cents worth

[Mike Carey]

Thanks!

When I was a kid my dad use to run the car up to 85mph, he would say "just burning the gunk out of the engine".

[Bodofish]

Sounds like either water in the gas or ethanol phase separation or both. If it's old gas drain and get new non ethanol. If you've never had ethanol gas then it's probably water.

Simple things to do that help enjoy playtime:

Always use fresh gas preferably non ethanol. Either filter your fuel and keep it clean and for god's sake take a look in the empty can once in a while. You wouldn't believe the crap and water I've seen in peoples gas cans.

When you get to the dock and any time the engine is going to set for some time disconnect the fuel line and let the engine run out. Or during a WOT run on the lake pull the line and let it run out which is a bit better. (pulls more fuel out of the bowl) I did this on my first boat engine and the carb was still spotless after 25 years.

Open up the trolling motors and run them at high speed. This heats them up more, burns off deposits in the cylinders and plugs and makes fuel and air flow through all of the carb passages. Also helps boil off moisture if you've gotten water in the fuel
Be careful adding additives like seafoam. Add the suggested amounts and don't do the "if a littles good mores better" philosophy because it can build up. Most additives don't burn the same as gas and can cause an engine to run lean making it hard to diagnose problems.
Just my 2 cents worth

I don't buy it, period. I've cleaned up a dozen small outboards with and never had a problem, I always mix at least twice the amount of Seafoam in the directions. It will pull any water out of the system. It's cleaned every single carb to running new condition, with out exception. It dissolves all the old varnish and junk out of the carb.
When the directions say pour an entire can down the carb or intake of an engine running at half throttle, I doubt your going to get a lean burn problem, running a small percentage in a tank of fuel.
It's doing the same thing every 2 stroke OB (chain saw, weed wacker, yard blower, etc.) in the world does. The fuel and oil gets old makes varnish in the carb and fuel pump. It starts to flake off and clogs the filters, screens and the diaphragm pump. Two ways to fix it, take the carb off and take it completely apart and clean it in the hot tank or run a cleaner through it till it all dissolves. The latter is much easier and more cost effective.

Just the way it is.

[duffy]

I was simply trying to tell the op how to prevent problems through preventive maintenance before it got to the extreme measures.

[Mike Carey]

I appreciate all the info, thanks guys. I'd be the first to admit I don't do enough routine care to my motors, which is dumb. No excuses.

[sickbayer]

Mike you ain't the only one mate. I never touched my kicker in the fire years of owning it. Although I seafoamed the main tank which fed the kicker once a year.

[Bodofish]

I appreciate all the info, thanks guys. I'd be the first to admit I don't do enough routine care to my motors, which is dumb. No excuses.

You and me both, hence the intimate repair knowledge......... And I've been repairing and rebuilding small 2 stroke motors since I was 15. Spent a couple winters rebuilding outboards to loan the natives in Alaska for our fish company, all in all about 50 outboards a winter. It's amazing what they can do to equipment when they don't own it. OK their own stuff too.....

[BARCHASER10]

I had a 1991 8hp Merc 2 stroke. I put at least 3000hrs on it, all I ever did with it is troll mostly in the salt. It just gave up in 2010 and I bought a 4 strk T8. I may have been able to fix it but I wanted a T8 and I figured nearly 20 years is enuff.

When it was nearly new, I had a similar problem. The exhaust pipe going down the leg of the outboard was simply plugged up with unburned gas/oil and carbon. It would run for a a minute or two and die. The fix it guy just reamed out the exhaust pipe out with round wire brush on a rod. After that when I trolled with it, I ran it at high speed for 5-10 minutes to burn out any residual gunk, and it worked fine. I do the same thing with my T8.

[Bodofish]

I had a 1991 8hp Merc 2 stroke. I put at least 3000hrs on it, all I ever did with it is troll mostly in the salt. It just gave up in 2010 and I bought a 4 strk T8. I may have been able to fix it but I wanted a T8 and I figured nearly 20 years is enuff.

When it was nearly new, I had a similar problem. The exhaust pipe going down the leg of the outboard was simply plugged up with unburned gas/oil and carbon. It would run for a a minute or two and die. The fix it guy just reamed out the exhaust pipe out with round wire brush on a rod. After that when I trolled with it, I ran it at high speed for 5-10 minutes to burn out any residual gunk, and it worked fine. I do the same thing with my T8.

Merc Power Tune will do the same thing with out taking it apart. It's scary the stuff it blows out when you spray it in.

[hewesfisher]

Why pay more for non-ethanol fuel to keep alcohol out of your tank and add alcohol with Seafoam? Seafoam contains 10 - 20% alcohol by weight - read the MSDS.

Since Mike's kicker is a Merc, 1 ounce each Mercury Quickare (Quickstor if not using fuel within 45 days) and Quickleen to 5gals fuel will keep it fresh and the fuel system clean without adding alcohol to your non-ethanol fuel. I don't have the luxury of using non-ethanol fuel where I live, only one station carries it and it is inconvenient to obtain, so my motors have only ever seen ethanol fuel. I treat every gallon of fuel, have done so from the very first tank, and not a single problem since new. IMO, proper maintenance is always cheaper than paying for service/repairs.