Need more power at elevation

[ilmostro99]

Gonna take the family up to a lake tomorrow that is at 5,000'. My boat, '99 Sea Ray 190 BR w/ carbed 5.0, 220 hp, stainless prop, is jetted great for sea level (where I live). When I go up to 5,000' I obviously loose power. Top speed drops from about 55 to 35 at that elevation, not a big deal, but it struggles to get on a plane. Is there a quick fix, say messing with the fuel/air mixture screw, that will give me a bit more power? Not worried about top speed, but would like to get on a plane quicker. And since I only go to this lake maybe 1-2 times/year, I'm not interested in rejetting or spending the money on a new prop. If I can't do it quick, easy, and cheap, (and be able to get it back to exactly how it is now when I come down), I won't mess with it.
Any advice?
Thanks,
Erik

 

[tashasdaddy]

Re: Need more power at elevation

don't mess with it. requires rejetting. just like an automobile.

 

[45Auto]

Re: Need more power at elevation

As TD says, it requires complete carbureter diss-assembly and re-jetting (smaller main jets). The mixture screws ONLY affect the idle mixture, and have no affect above idle speed. Don't screw them up.

 

[Silvertip]

Re: Need more power at elevation

A prop with less pitch will help with hole shot but you will need to watch RPM to prevent over reving. And be sure to install the original prop when you return to lower elevations.

 

[bruceb58]

Re: Need more power at elevation

The reason that you have way less power is because you wave way less oxygen at that altitude. You would only make up a fraction of the power loss by re-jetting and you would only want to do that if you were permanently leaving the boat there. Putting on a lower pitch prop is the only thing you really can do.

 

[SNye45]

Re: Need more power at elevation

I agree with re-propping.

I bought my outboard at a dealer based at sea level, but I live at 3,000 ft. When the dealer heard this, he changed the prop from the standard 21" to a 19".
Engine runs great and I max out at just under 6,000 rpm. (Engine range 5,000 - 6,000).

This would be simpler than messing with the carb!!

Just a thought

 

[ilmostro99]

Re: Need more power at elevation

Yeah, that's kind of what I thought, but was hoping for some magic. I'm not going to mess with it. Prop would be the way to go, but can't really justify the price for a casual weekend trip. Thanks again. I can always count on good advice from this forum.
Erik

 

[12vMan]

Re: Need more power at elevation

You should carry a spare prop anyhow. Check ebay or CL, you'll find some great deals on used props!