Auxiliary Outboard Engines

[MrBill_FLL]

well a carb rebuild is just a really good cleaning and adjustments...

so I'd say its back to fuel issues.

when you use it, how long is that normally? 15 min or more? or much less like 5 min?

 

[draymond]

well a carb rebuild is just a really good cleaning and adjustments...

so I'd say its back to fuel issues.

when you use it, how long is that normally? 15 min or more? or much less like 5 min?

Closer to 5 min than 15

 

[draymond]

Hello All,
Mechanic called yesterday (hurricane set us back a bit) and said it was the spark plug. John23883 had said his problem was a spark plug that was cracked. According to my mechanic, the spark plug was not working properly as it had a gunky kind of glaze over the spark end and was not producing the appropriate spark.
Possible? Make Sense? Still caused by bad fuel?
Thanks,
Dean

 

[Winkfish]

That could be it. Excessive carbon (oil) buildup on the plugs ("fouled plugs") can certainly cause that kind of problem. I would recommend dong the Sea Foam treatment I mentioned above, then use a maintenance dose after that.

 

[kloudie1]

When you use the engine, ya need to work it to get the combustion temperatures high enough to burn those deposits off the plug.. run the engine harder for a longer time than you are doing.. If that doesn't help, or is not feasible, a hotter heat range spark plug will get hotter faster and run hotter at your operating conditions which should keep the plugs cleaner.. Get the mechanic to talk about that and maybe install the next hotter heat range spark plug..

 

[draymond]

good ideas, will do

 

[grantar2]

My 2010 Tohatsu 8hp on my 25 Venture has been flawless. I had has some problems with my 8hp Honda, and I still use that engine on my inflatable, but my mechanics advice has run true. My boat is marina kept in California 365 days a year. Don't use the gas from the fuel dock, go to service station. Only use Chevron and put stabill in it. They have found (Trade Wind Inflatables) that the Techron stuff really makes a difference in keeping the engine clean. Now my engine gets used up to 50 times per year, but still I can go a month without starting it and not have a single issue. The only problems I have had with the motor since new are the tilt, and the Tohatsu fuel line coming slightly unplugged. If you have a problem that is the first thing I check.
In So Cals light winds, I tend to motor more than you might, the average is about a half hour per outing, but I have also cruised the 28 miles to Catalina on motor and no issues there either.

 

[SamLust]

You realy do not want to be playing with spark plug heat range unless you have a deep knowledge of what you are doing. The plug used in that engine is hot enough as it is. Overly hot spark plugs can make pretty little holes in the tops of pistons. If you expereience consistent fouling of the plug you might consider switching to a PROJECTED NOSE plug of the same range, and that only after you have determined to a certainty that the tip will clear the piston at top dead center and not interfere with valve travel. If they exist in that plug, NGK's designation will be a "P" somewhere in the plug number. Champion if I recall used "Y" to indicate projected nose. These plugs expose more of the central, white insulator to the combustion swirl, thus keeping them cleaner and less likely to foul. I ran them for years in my Kawasaki KZ 1000. It was tough to get jetting right in the low and mid-range and the projected nose helped off idle throttle response.

I just bought a barely used Mercury version of that engine. Have not gotten it out on a bout yet but Just running it in the tank I do find it to be a very cold blodded engine. Does not run well till it warms up.

Pay attention to the OE fuel filter. The plastic mesh filters Tohatsu uses seem pronr to frequent plugging. The filter I see on mine is iline and could be replaced by a fiber element disposable. That will happen to mine very soon.

 

[bffatcat]

I have an 8hp 08 4stroke tohatsu I run it out of fuel every time I use it. as per the dealers advice. In MA the fuel is 10% ethanol. you can not get ethanol free gas in MA. I do not run it much. There is one thing Im doing. After 30 days I pour any fuel left in the 3 gallon tank into my car. I do not mix old fuel with new. I use mid grade. I service the engine at the dealer at the end of every season. I have had no trouble with the engine ever. It always starts on the second pull.

From your comments it sounds to me like you are using old fuel with ethanol

 

[draymond]

bffatcat,
A gas station sells ethanol free gas by the marina and I used techron in it. I note that I do not empty it every 30 days and thought because of the treatment and ethanol free, it would be good for the season. I need to note to change it often.

 

[Winkfish]

Draymond, new fuel is certainly better than old fuel, but in my outboard I have used fuel that has sat for up to 6 months with no problem, having added Stabil and Sea Foam before the layup. What you really need to do, though, is run the engine for about 10 to 15 minutes/week even if you don't take the boat out.

 

[draymond]

Common theme as i review all comments is run the engine!

You use stabile and seafoam?

 

[Winkfish]

I do, D. A few months after I got my boat, which at that time, the engine was 20+ years old, I did the Sea Foam treatment. since then, I put at least 2 cans (sometimes 3 or 4) of Sea Foam in each 12 gallon gas tank (I have two external 12 gal plastic tanks) plus a maintenance dose, or a little more, of Stabil (the blue kind). It's OK to use more than the recommended dose of Sea Foam and Stabil.

Remember, the Sea Foam and Stabil count as "gas" when mixing in your 2-stroke oil.

As for 2-stroke oil, don't use the cheap Home Depot stuff like you'd use in a weed-whacker. Get a good 2-stroke oil made for outboards. I use the Mercury Quicksilver brand.