Altitude Issues

[mercman2]

Re: Altitude Issues

I agree with the prop change. Shouldn't be any need to rejet the carb. I live in florida but had my 115 merc at 3700 feet for 2 years at Lake Powell. I had to go down 2 degrees on the pitch in the summer. Seems like the ambient air temp had alot to do with it. Naturally it sounds like your pulling a pretty good load so you might have to go down another prop size. Propping a boat can be a science good luck.

 

[mercman2]

Re: Altitude Issues

I agree with all the other posts about carb adjustment and all that, but unless you have excess oil running down the mid section or black soot on or around the prop your carbs and timing are probably good. Usually the jets are bigger at sea level and get smaller the higher you get. Really the boat should run just fine with the original jets, so I would start by doing a general shake down with a compression and spark check just to make sure all of your cylinders are intact.