Mercury 250 Optimax

"I'm looking at an aluminu

"I'm looking at an aluminum jet boat with very low hours. It boasts a 2004, Mercury 250 Optimax jet drive. I'm not familiar with a 2 stroke inboard system. Could I expect long life and trouble free service?"

1) what are the changes t

1) what are the changes to be done for a refregeration plant if we are changing refregerant of R12 to r22?

2)what is meant for singing of propeller?

"I am having a problem with my

"I am having a problem with my Mercury optimax 250 XS. At WOT I am only getting 5000 RPM with a 24p prop 4 blade. I am at an altitude of around 5000 ft and running around 50 mph(GPS). With the boat fully trimmed but the Hydraulic jackplate down the engine begins to lose power after about 1 min. it then acts like it is starving for fuel. If I cut it back to 1/2 throttle and 1/2 trim it runs fine but I can only go 40 mph. Could this be a prop or fuel issue. When I ran it in San Diego I ran a 27p prop and ran 80(GPS)no problem. I thought with a 250 I should be able to turn the 24p prop and get at least 6000, rpm. Any Ideas?"

"Frank it may sound like that

"Frank it may sound like that you are not getting enough air. San Diego is is pretty much at sea level and you would run fine, but at higher elevations you need more air to mix with the fuel. Before doing anything I would talk to your local dealer because they should have an idea what the air/fuel mixture would be for your area, and if your getting 80mph with an 27p I would stick with that pitch.
Ron"

I have a 250 optimax in a utop

I have a 250 optimax in a utopia 2002 seadoo jet boat. In the process of replacing the alternator and all bolts removed but can't get at the two electrical connections facing aft (tight space and can't see). Any tips would be appreciated. Thanks.