1971 125hp Johnson tuning

[rekamlias]

I just ran my 1971 125hp last night for the first time off the hose and in the bay and it was great fun after all the work on the boat and motor. First time i reved the engine since the manual says dont rev it on a hose.
First what is a good idle speed for this engine. At 400 rpm she will stall going into gear. Is 500 to 600 rpm hard on the gears?
What is the maximum rpm at full throtle for this engine. She ran at 1200 rpms at full throttle. 4 people in the boat. Surfing down some big wakes she was able to hit 1400 rpms and felt good. Just want to know where to set her idle and what to expect as max rpms

Thanks in advance
mike

 

[tashasdaddy]

Re: 1971 125hp Johnson tuning

that motor should idle around 550-650 in gear. you have hydroelectric shift if it is a 71. wot rprm should be 4500-5500.

 

[rekamlias]

Re: 1971 125hp Johnson tuning

Yes it is a a hydro electric shift

wot = Wide open Throttle?
rprm = rpm or something else?
4500 to 5500 rpms would be crazy fast but thats ok with me

Thanks

ps go gators!

 

[tashasdaddy]

Re: 1971 125hp Johnson tuning

rprm typing error rpm, wot yes, do you have a tach, are you sure it is right ? 1200 would be a just above a high idle.

 

[rekamlias]

Re: 1971 125hp Johnson tuning

Yes I have a tach and I may have to adjust it. It is a teleflex and it has 1, 2 and 5 mutilpier. I just installed it yesterday and do not know what setting is required.