Went fishing this morning, and on the way back, I noticed I was not getting quite up to speed. Instead of mid-60's it was low 60's/upper 50's. I hadn't gone in over a month, and the gas was low, until I filled up this morning. Could it have been just some old gas? I didn't notice any sputtering, or bogging just a lack of umph. I have a one year old 200 hdpi yamaha. I always use stabil ethanol treatment and ring-free on every fill up, but wonder if the gas still broke down or if I have other issues?

Any thoughts are welcome.

thanks

These recent hot summer temps combined with the humidity will rob your engine of a couple mph's.

When the temps and humidity come down in the fall, my boat seems to run a lot stronger!

+1

This heat will do it ever time. Had mine out this morning (late morning) and felt like it was down 50 hp at least.....

A recent article in a boating mag did research on two stroke outboards that showed a loss of 15% hp on a hot humid day. That will equate to at least 3-5 mph on any boat.

Factor in water temps of 90 degrees and you have a recipe for loss of performance.

Whew! That makes me feel better. Is there anything we can do to offset this? Some octane additive or something?

Moving up North will work as long as you avoid a big elevation change.
I top out at 55 now instead of 59 when its cooler outside and the water temp is lower.

Nope!

Just ta reinforce what we're sayin' I went to tha lake this mornin', had no problem bumpin' tha limiter at 7800 , by 10 am it was 72 ta 73 hundred at best ............

TLW, If you don't mind me asking what motor has the limiter set at 7800 rpms ?

Consumer 280.......Merc/Mariner. Its actually supposed ta be 7750 if ya split hairs

Thanks, so has it been dressed up a little, and what hull are you running this beast on ?

003 allison. Its a bone stock 280. I've got another powerhead that started tha same way but its no longer tha same motor. Is an unlimited rpm "real hot rod" motor.......Just something ta keep and old man entertained

Sounds hot I bet it puts up some solid numbers.

Yeah, it runs decent. A TRUE anytime 88 ta 90 but has embarassed several so called gps'd 100 mph boats with tha stock motor...........