Reprop a 35 Johnson

[40magnum]

I have a 1976 35 hp Johnson w/ an 84 powerhead. The man I bought from had it for years then one day it didn't have power to plane off. He told me the motor was worn out. I put it back together and had it running and found that it had no power. Started looking at it and found that the trigger was not advancing all the way. Got that working took it out again and it did just fine except it didn't sound like it was turning enough rpms. He fished by his self most of the time (He weighed about 165 lbs). My friend and I weigh 405 together plus our gear is why I think I can only turn 4000 rpms with a 10X15P. Does it sound like I need to go down to a 10P to get 5500 rpms or should I be trying to find something wrong with the motor? Thanks.

 

[hidef]

Re: Reprop a 35 Johnson

I would say you are over propped. Although without knowing what size boat you have and how fast you are going it makes it tough to give the correct answer. 11P prop would give 600 RPMs and 9P would give you 900 more.

 

[40magnum]

Re: Reprop a 35 Johnson

It is a 14' Winyah going 24 mph gps.

 

[hidef]

Re: Reprop a 35 Johnson

You want a smaller prop. a 9, 10 or an 11 will make a big difference your call on how much you want her to turn but figure 300 RPMs for every two inches.