Yamaha 150 Saltwater Series II Idle

[mac83]

I've noticed a higher idle when I flush the motor with muffs on, yalls around 800-1000 RPMs. It flucates between those and almost sounds like it's missing a little. In the water, dosnt do it as much. A slow troll is a struggle, usually can't get it slower than 2mph. Boat is a 98 Adventure 208 with hardtop. I feel like it shouldn't struggle to go slow. Any ideas guys? Should I just get the idle adjusted possibly?

 

[mac83]

??? No one

 

[artodea]

Is that a carbureted engine? If so, a good cleaning and rebuild may be in order.
Before I repowered I found the yamaha board to be extremely helfpul (and active):
http://www.yamahaoutboardparts.com/forum2/

 

[DennisG01]

Be patient, not everyone works on your schedule. :wink:

What is "yalls"?

In many cases, 2-strokes don't idle very well out of the water. The back pressure of the water (when in the water) on the exhaust helps calm them down.

Need more info on the engine and specifically what is happening... Trolling at 2mph may just plain be impossible with the hull/engine combo. I've never actually measured it, but I'm sure my idle speed is more than 2mph. You may want to invest in a trolling motor.

Fuel quality... fuel filter... fuel pressure... plugs/wires....

 

[seasick]

Be patient, not everyone works on your schedule. :wink:

What is "yalls"?

In many cases, 2-strokes don't idle very well out of the water. The back pressure of the water (when in the water) on the exhaust helps calm them down.

Need more info on the engine and specifically what is happening... Trolling at 2mph may just plain be impossible with the hull/engine combo. I've never actually measured it, but I'm sure my idle speed is more than 2mph. You may want to invest in a trolling motor.

Fuel quality... fuel filter... fuel pressure... plugs/wires....

There is no way my 208 with the 150 can run at 2 mph. The only way to go that slow is by shifting in and out of gear and that isn't easy while fishing.

 

[DennisG01]

There is no way my 208 with the 150 can run at 2 mph. The only way to go that slow is by shifting in and out of gear and that isn't easy while fishing.

Do you remember those "plates" that would install on the lower unit and then drop down behind the prop to stop some of the prop wash/forward momentum of the boat? What were those called... trolling plates, or something? I wonder if they still make them?

 

[enfish]

My motor, though slightly older vintage, always idles around 800-900 RPM while out of the water and 600-700 while in the water. As Dennis stated above, the back pressure on the exhaust underwater seems to smooth things out. Assuming you have a 17 inch pitch prop, idling in gear @600 RPM is going to be about 3-4 mph, assuming a prop slip of somewhere between 10% and 50%, ignoring wind and current effects. 2 mph is tough unless you throw out a drift sock or install one of those trolling plates on the motor.

 

[mdscole]

I have 2 of the same engine on the back of the 248. They don't do slow well. Running a single - I can get down to about 2.8 mph. And the motor hates it. So - I threw on a honda kicker. That does slow well and doesn't burn much gas.