81 ss440: carb issues or in need of a tear down?

[duke06]

picked up an 81 SS440 a couple of weeks ago.it is in pretty decent shape.was told it had a complete rebuild last winter.(new pistons,rings,seals).it always starts on the 1st. or 2nd.pull.problem is once i get up to about 30 mph. and around 4500 rpm it seems to hit a wall. it will not rev any higher or go any faster.first i thought is was a clutch issue.cleaned and rebuilt primary (comet duster) and cleaned secondary clutch. still same problem. it is running very rich.lots of smoke out the exhaust. pulled plugs they were very wet. it has stock carb but is running 145 main jet. i thought stock is 135? checked compression with carb off and it is only 60 psi on both cylinders. now i'm wondering if the cylinders got washed down due to being excessivly rich? should i rejet and pull off the top end to check things out? oil injection was disconnected so i'm running premix at 50:1.any thoughts would be appreciated.

 

[Yamaha Nutz]

60psi????? that think should not even run ...........bump the pre mix to 40:1 but you problem could be the duster clutch .........not a good clutch for that sled ............check for plugged exhaust

 

[duke06]

thanks for the info.i didn't think it would run with that low reading either. maybe the gauge is wrong. just trying to figure out where to begin.when i rode it, it pulled strong up 4500 rpm lifting the skis off the ground then nothing more. it also has an aaen pipe.