CanNOT have a good day on the water!

[Fughetta-boat-it]

Frustrating here. Got my 75 Harris FloteBote w/ a 1967 35hp Chrysler.

1st trip out: motor ran great for a couple of hours, then wouldn't want to run at lower RPM's without stalling out, then it was hard to start. Had to come in somewhat hot and with the motor off. Got 'er docked up and out, went home and started swapping for the 9.9 Mercury that I had already bought. Wasn't about to put any money into a 47 year old motor.

2nd trip out: I have the 1993 9.9EL Mercury installed. Ran great, but winds were wicked and the winds blew is in fast. Had the motor in neutral and reverse just to try and slow down. This pontoon is much more sensitive to wind than my old bowrider was. Still got it docked up, but again, without that feeling of a successful day and nice easy docking.

3rd trip out (today): Had a great day out, dropped anchor so the kids could fish. Took 3 tries to start back up, then it would continually run rough. Sounded like a miss. Kept on going for about an hour, then on the way back in, it really started bogging down. At WOT, it sounded and felt like it was just above idle. Popped the hood, the cables are all where they belong. Carb was at WOT but the HP was not there at all.

So, forget about 1st and 2nd trip... those problems are solved. What's going on with the 9.9 where it bogged down today? I'm going to start to check things over, but where to start? Fuel filter? Spark plug? I'm wondering if this could be a gas-oil mix problem? I'm good with 2 stroke lawn equipment, but new to outboards. What diag tips might you have and where should I start? Any help or advice is appreciated.

Thanks,
FBI

 

[Fughetta-boat-it]

 

[Fughetta-boat-it]

Running 50:1

 

[no704]

Ya know outboard 2 stroke oil is different than lawn 2 stroke oil ?

 

[Fughetta-boat-it]

No! Or should I say oh no?!?

 

[redneck joe]

really? How?

 

[Fughetta-boat-it]

I'm running STIHL oil at 50:1.

If that's wrong, then dang, stupid me. I assumed it was the same. If it's different, I'm curious as to how, but more importantly - could that be causing my problems, and most importantly, any permanent damage? Easy fix? Just mix a new tank with the right oil?

 

[Fughetta-boat-it]

Researching this now. I see there is a difference in that the liquid cooled outboard motors don't run as hot as a chainsaw, and therefore the oil mix is different. It appears as if the improper oil can leave potentially catastrophic deposits behind. I'm hoping after less than 5 gallons, that I haven't screwed anything up. I'm mixing new fuel with the right oil, and I assume some Seafoam would be a good idea?

 

[no704]

Ya know outboard 2 stroke oil is different than lawn 2 stroke oil ?

 

[Fughetta-boat-it]

If someone could give me a list of things to do in order to make sure I don't blow this motor, I would appreciate it.

I assume fresh fuel, a new fuel filter, and a new sparkplug are a must. Probably Seafoam too?

 

[midcarolina]

The brand of pre mix oil is NOT the problem............ I would start by checking for water in fuel or bad/weak gas, replace any fuel filters. It could also be as simple as the gas tank is not vented properly...........

 

[Big Rig]

Sounds like something in the carb. clean carbs and make sure the tank, lines, and fuel filter is clean. There isn't enough difference in oils to cause your problem. the new 2 stroke oils that are available today can be used in any 2 stroke engine. don;t worry about the oil brand too much.

 

[Fughetta-boat-it]

Found a bad plug. Pretty sure the wire was loose. New plugs, new fuel w proper mix, checked filter- it was fine. Tightened everything up- idles, throttle up and runs fine in a bucket. Hoping for a good Sunday! . Thanks for the help and suggestions. FBI

 

[roscoe]

Definitely use TCW3 rated oil in your TwoCycleWatercooled engine.
Do not use oil for air cooled engines.

And yes, I would add and ounce or 2 of Seafoam.

I use with every tank of gas to help keep the fuel system clean.

Plug wire was probably the issue.
Check all other wires for tight connections, broken insulation, and corrosion.

Late afternoon is usually the windiest part of the day.
If you fish another 6 hours, and come in at 11 pm, you will likely have an easier time at the dock.