Pontoon Boat & Deck Boat Forum

When my '04 Yamaha, 2 stroke, oil injected, carburated, 50HP motor is running at idle or slightly higher rpm I am noticing a light smoke coming from it. When I am at cruise speed I don't see it, or it just dissipated so quickly I can't notice it.

There is also a smell of gasoline when I cruise at idle speed. I am thinking that maybe it is running to rich?? It also smokes at start up quite a bit. I do have to keep the motor tilted up when not in use because I am in a wet slip. Not sure if this affects anything. Ideas?

Don't worry Ron I haven't seen a 2 stroke that doesn't have those symptoms...

Yep, everything you have described is a "2-Stroke" thing, and happens to mine as well. 2 strokes don't run well at low RPM, and honestly, aren't made to. They are made more for the mid to higher RPM range, where they perfrom the best. I'd say as long as you change your plugs at least every other year ( or every year if you use it a lot) and keep an eye on your fuel and other maintenance, you're good to go.

Ditto on the "2 stroke thing". That is why I have a 4 stroke. We have so much of the bay that is slow speed only that I had to get rid of an otherwise good 75 2 stroke.
You could dump your favorite "cleaner" in the gas to try to get some of the gum out and throw a set of plugs at it but the best thing you can do with a 2 stroke is run it 4000+ RPM for an hour or so every time you go out. That is usually enough to flush out the carbs and burn the carbon out of the system.

There are lots of things people dump in the gas to keep it "fresh" but the best solution is to run often enough so it doesn't have time to get stale. You are in paradise and your boat is in the water all the time, you have no excuse not to

Welcome to the 400 hour a year club!

GregF wrote:...the best thing you can do with a 2 stroke is run it 4000+ RPM for an hour or so every time you go out.

That's what I keep telling my wife...lol



I usually only have to idle for about 10 min before I get out to open water and 4000 rpm, but a couple weeks ago I took the back way to my uncle's house which is about 30 min of no wake/idle speed which is when I first noticed it.

I usually try to get out at least once a week, but sometimes it's every other week. I still add a little StarTron blue with each new fill up.

curtiscapk wrote:Don't worry Ron I haven't seen a 2 stroke that doesn't have those symptoms...

Thanks, that's what I suspected but wanted some reasurance.

GXPWeasel wrote:Yep, everything you have described is a "2-Stroke" thing, and happens to mine as well. 2 strokes don't run well at low RPM, and honestly, aren't made to. They are made more for the mid to higher RPM range, where they perfrom the best. I'd say as long as you change your plugs at least every other year ( or every year if you use it a lot) and keep an eye on your fuel and other maintenance, you're good to go.

As long as I could "run", my old 2 stroke was doing great but when the manatee huggers trumped sanity here I simply had to get rid of it.

I just could not go fast enough, long enough to keep the carbon out.

Tell your wife, if she insists on going slow, she has to come up with the $6000 to buy you a new 4 stroke.
I can't say enough good about the Mercury big foot 60 EFI 4 stroke. This thing has not burped in 3000 hours and 9 years.

I can keep up the rpm's for an hour (even at 4000rpm's it's not too fast), but should I still use some seafoam to help the process?

I am not a huge fan of additives but some people swear by them. I think they are mostly to make up for owning a trailer queen.
None of the commercial operators I know, who actually use their boats regularly, use any of this stuff.

Interesting...this may be a contoversial topic. I'm interested to see some of the other comments that may follow.

...I'm off to run my motor, and burn off that carbon

For some reason I have been hesitant to 'run' for too long...I don't really know why...but sounds like it is good thing...

Loner here..........love my opti with dfi
doc

GregF wrote: Tell your wife, if she insists on going slow, she has to come up with the $6000 to buy you a new 4 stroke.
I can't say enough good about the Mercury big foot 60 EFI 4 stroke. This thing has not burped in 3000 hours and 9 years.

I was just kidding...she actually wants to go faster, and upgrade to a 90HP, but I doubt we will have the dough for a while.

Does Merc make a 90HP big foot?


Just a video of me being a jackwagon behind the camera as usual...

A "big foot" is a 40-60 HP with the same foot they put on a 90.

I do have a 14 7/8 x 15 SS prop I can make you a deal on if you do go with a 75 or a 90 Merc. On my boat it would probably be right with a 75 but a heavier boat might use it for a 90.

I found this motor online...2006 90HP Mercury 2 stroke for $3900. Would you ever buy a used motor? It's about 1/2 price of a new one.



http://cgi.ebay.com/ebaymotors/2006-MER ... 27b98974a0

I would put another three grand on the stack and get a new Optimax or a 90 EFI 4 stroke for $200 more.

Do you have any idea about the history of the used motor. Four grand is a lot of money for a pig in a poke.