Re: no top end in a 71 85hp
Check the fuel pumps for a ruptured or leaking diaphragm. If the diaphragm goes it'll dump raw fuel directly into the crankcase.<br /><br />Check your distributor and carb linkage to make sure the distributor advances fully to the 'spark stop', and the throttle butterflies on both carbs open fully.<br /><br />Take the plugs out, stick them back in the spark plug boots, and ground them firmly to the block. Crank over the motor and see if you get a good, hot, purplish spark on each plug.<br /><br />Do a compression check. You shouldn't have more than 10 psi variance between the highest and lowest cylinder, and hopefully it's less than 5psi.<br /><br />If that doesn't help, report back with further symptoms and we'll thrash on the problem some more!.........ed
