A few questions abut my 1983 75 horse.

I have a 1983 75 horse mounted on a 17ft 1971 Glastron Crestflite. When the throttle at the drivers seat is at full throttle I have looked at the throttle on the engine. I have maybe a half to one inch left where I can manually push it down and get more speed. Right now the engine usually runs at about 4100 to 4200 rpm at full throttle. Would it be safe for the engine if I adjusted the throttle cable to where I gould get that last bit of throttle for more speed or should it be left alone ?
Is 4200 about right at full throttle ? Im getting about 28 mph according to the gps. The other question is Im wondering what brand name of repair manual is preferred as I have seen a couple different aftermarket brands. And last of all would a prop change get more speed ? Im pretty sure the one on it is the factory prop.
Regards........... Jim up near Flathead Lake Montana

Re: A few questions abut my 1983 75 horse.

The top rated rpm for the 1983 75hp model is 5500 rpm. Your top full throttle rpm should be close to this reading.... 5300 would be good.

At your full throttle lever setting, the carburetor butterflies should be completely open (horizontal). Adjust the adjustable trunion on the throttle cable at the engine's cable retaining clamp to obtain this setting.

Prop? I'll leave that to someone else. Try the above first.

Re: A few questions abut my 1983 75 horse.

you may have to do a link n sinc, to achieve wot and a reasonable idle. also could have a failing cable.