Hi everyone,
Been here a couple of times asked questions and received some awesome help, been reading it again today and well.....the questions asked made me think of some more questions I have being that I am a newbie boat owner.
So here we go.....
How does one determine the proper pitch of prop for a boat motor combination, is there a starting formula ? I have a 16' Lowe river Jon 6'10" across the gunwales at the back in the widest part. I went to the Lowe site and comparible current boats they make put it in the 400 to 450 lb. range for the boat only. I have a couple of heavy 7/8 plywood casting decks on it two 6 gal fuel tanks a deep cycle marine battery and a console. So I figure rough estimate it adds about another 250 lbs to the boat less the motor weight. The engine is a Johnson 70 VRO 1988 vintage, and also discovered at the Lowe site that this boat is only rated for 35 hp.
Firstly am I going to get in deep do-do with water patrol haveing the 70 hp on this boat ? I bought it with this motor already on it and knowing nothing about boats didn't realize that it was way over motored if you will. Also the previous owner had the cutout on the stern filled in with aluminum up to the height of the surrounding transom, welded in and braced, very nice job of welding (I am a certified welder). But still it is a user modified addition not factory. The boat is a rivited design not the fully welded design that Lowe makes which is rated to 85 hp. It is also quite old a 1976 model.
So now I am wondering if I will even be able to license it, or if no hitches there, if I will be ticketed if I get stopped on the water ?
Anyway back to the pitch question.....at this weight level, and this HP of motor, what would be the proper pitch ? It currently has a 19 pitch three blade prop.
It starts and runs good, (in a barrel anyway) I haven't checked things like the compression as I have no compression checker. The electric choke works fine. The VRO has been taken off the engine and I was told to run it at 50:1 is this the correct oil gas ratio ?
I sure wish I had known enough about boats to know that this motor was way to big for this boats rating before I bought it. I just assumed it was modified because the Johnson 70 was a long shaft.
Thanks for all the great help this forum provides !
Marty
Been here a couple of times asked questions and received some awesome help, been reading it again today and well.....the questions asked made me think of some more questions I have being that I am a newbie boat owner.
So here we go.....
How does one determine the proper pitch of prop for a boat motor combination, is there a starting formula ? I have a 16' Lowe river Jon 6'10" across the gunwales at the back in the widest part. I went to the Lowe site and comparible current boats they make put it in the 400 to 450 lb. range for the boat only. I have a couple of heavy 7/8 plywood casting decks on it two 6 gal fuel tanks a deep cycle marine battery and a console. So I figure rough estimate it adds about another 250 lbs to the boat less the motor weight. The engine is a Johnson 70 VRO 1988 vintage, and also discovered at the Lowe site that this boat is only rated for 35 hp.
Firstly am I going to get in deep do-do with water patrol haveing the 70 hp on this boat ? I bought it with this motor already on it and knowing nothing about boats didn't realize that it was way over motored if you will. Also the previous owner had the cutout on the stern filled in with aluminum up to the height of the surrounding transom, welded in and braced, very nice job of welding (I am a certified welder). But still it is a user modified addition not factory. The boat is a rivited design not the fully welded design that Lowe makes which is rated to 85 hp. It is also quite old a 1976 model.
So now I am wondering if I will even be able to license it, or if no hitches there, if I will be ticketed if I get stopped on the water ?
Anyway back to the pitch question.....at this weight level, and this HP of motor, what would be the proper pitch ? It currently has a 19 pitch three blade prop.
It starts and runs good, (in a barrel anyway) I haven't checked things like the compression as I have no compression checker. The electric choke works fine. The VRO has been taken off the engine and I was told to run it at 50:1 is this the correct oil gas ratio ?
I sure wish I had known enough about boats to know that this motor was way to big for this boats rating before I bought it. I just assumed it was modified because the Johnson 70 was a long shaft.
Thanks for all the great help this forum provides !
Marty
