Logo

High altitude power loss

sargew

New member
"This may be completely normal

"This may be completely normal, but I wanted another opinion anyway. I took the Nissan 9.8 out on a lake in Utah yesterday. The elevation is pretty high, about 8000+ feet. Put the boat in the water and fired the Nissan. She started right up and and idled fine. When I was warmed up, after about 3 minutes I applied about half throttle. The RPM's came up slowly, but not much power. After a few more minutes I opened the throttle full. The RPM's topped out at about 3400, and the top speed measured by GPS was a hair under 5 knots.

I am assuming that it was due to the increased elevation and thin air. This is only the second time I have run her, the first time was at sea level on a lake. She topped out at about 5800 RPM and came up on plane pretty easily. The Nissan is on a 11' inflatable with a high pressure floor.

Does this sound normal operating conditions at this altitude? I will be traveling all over the country, and in all kinds of waterways. I didn't know if there was any adjustment possible for running at high altitude.

Thanks, Marty"
 
What I have understood and rea

What I have understood and read about my older outboard engines you have to compensate for the altitude. I haven't read how you do it on the Nissan/Tohatsu engines as I don't plan to go to any altitudes with my Tohatsu. I believe you will find how to compensate for the altitude in your owner's manual.
 
"I don't remember if I rea

"I don't remember if I read anything like that for my Tohatsu, but I know I read it for my old Johnson 15 hp I bought 1987 and retired 2002 when I bought the Tohatsu."
 
"I rechecked the manual, nothi

"I rechecked the manual, nothing about high altidude adjustments. The search continues."
 
Back
Top