Loss of power above 4000ft

[3inan84]

Hey there,

I'm travelling in Mexico with my family in a 1983 21 ft sunrader 22r. Recently we experienced a very significant loss of power going uphill or even just up a curb. As a result we visited several mechanics which all together changed spark plugs and cables, replaced clutch, 'washed' the carb, adjusted the hand brake, added a Lucas additive to the engine and took out the bad catalytic converter. All of these combined made for a nearly unnoticeable difference. But when we dropped below 4000 ft again suddenly power seems to hhave returned. I then realized that the problem started when we went higher than 4000 the first time. Is this normal or is there something wrong? We went from going up a hill in 3rd or 4th gear to going up an equivalent hill in 2nd and crawling up it. Seems like we need to push the engine to up of 4,000 rpm to get the same acceleration as we did at 2,500 rpm before and even then I can't shift quick enough to not lose all the power... 

Is something wrong with the altimeter or some other component? It seems like an unreasonable loss of power.

 

Thanks,

Itamar

[linda s]

Well it just needs more air. Your carb model doesn't automatically adjust like a fuel injected one. Even with fuel injection 2nd gear going up hill at high altitude is normal. Adjusting timing and carb should help some. There is an air fuel adjustment screw hidden somewhere on your carb that can lean out the mix but don't know where it is. Someone here will

Linda S

[fred heath]

http://www.fixya.com/cars/t1006445-22r_carb_high_altitude