90HP V4 Johnson on a Sakonnet - top speed? - Moderated Discussion Areas

  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: Whaler Performance
  90HP V4 Johnson on a Sakonnet - top speed?

search | FAQ | profile | register | author help

Author Topic:   90HP V4 Johnson on a Sakonnet - top speed?

bsmotril posted 07-05-2005 03:27 PM ET (US)
I've got a mid eighties 90HP V4 on a 66' Sakonnet, and was wondering what similar rigs are seeing for top speed. I don't have a tach, but will run 42mph with two aboard, and 44 with a single driver measured with GPS. My prop is an OMC 19" stainless 3 blade. Does anyone with a similar configuration know what RPM that would be at WOT? Also, what is the gear ratio for those mid 80's V4s?
BillS
rumrunner posted 07-05-2005 06:37 PM ET (US)
Do a search on this topic, we just had an extensive conversation regarding 90hp top speed with various prop pitches. Should be about 7-10 days ago. If you can't find it, I'll try looking for you.
bsmotril posted 07-05-2005 09:48 PM ET (US)
Found this one, but it is for a Dauntless 16 hull, and a Merc Motor, not OMC:
http://continuouswave.com/ubb/Forum4/HTML/003623.html
Nothing else within the last 10 days
Bills
rumrunner posted 07-05-2005 11:05 PM ET (US)
http://continuouswave.com/ubb/Forum4/HTML/003499.html
Title is deceiving, but a lot of prop pitch talk involving Montauks (I realize no Sakonnets, but good info)
bsmotril posted 07-06-2005 10:29 AM ET (US)
Thanks for the pointer, that was an excellent thread.
BillS
Teak Oil posted 07-07-2005 12:07 AM ET (US)
Sounds like you are propped right as far as mph goes. Get a tach.
My 1985 Evinrude gets 43-44 with two and some fishing gear, but I have a jackplate and ss prop. When I was mounted on the transom I got the same numbers you are getting now
Robob2003 posted 07-07-2005 09:58 AM ET (US)
bsmotril,
I'm running a 1966 Sakonnet with a 1980 100 HP Johnson turning a 17X13 stainless 3 blade prop, which is painted black, and on my GPS I run about 40 MPH at 5500 RPM. I don't like to run it at WOT so don't usually go much beyond 3000-3500 RPM and 20-25 MPH , a range it seems to like.
It's old like me:-)
Bob on Tampa Bay
P.S. I thought I had an aluminum prop but the prop shop told me what it was when I took it in for ding removal.
bsmotril posted 07-07-2005 10:20 AM ET (US)
Do you know what the gear ratio is for the lower unit in your motor?
BillS
Teak Oil posted 07-07-2005 11:38 PM ET (US)
All the old crossflows had 2:1 lower gears.
LHG posted 07-08-2005 02:59 PM ET (US)
My in-line 6 Mercs have 2:1 gears also, and with a 19" pitch prop, the prop chart shows 46-47 MPH at 5600 RPM. So you are probably running at maybe 5300 RPM.

Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.

Author	Topic: 90HP V4 Johnson on a Sakonnet - top speed?
bsmotril	posted 07-05-2005 03:27 PM ET (US) I've got a mid eighties 90HP V4 on a 66' Sakonnet, and was wondering what similar rigs are seeing for top speed. I don't have a tach, but will run 42mph with two aboard, and 44 with a single driver measured with GPS. My prop is an OMC 19" stainless 3 blade. Does anyone with a similar configuration know what RPM that would be at WOT? Also, what is the gear ratio for those mid 80's V4s? BillS
rumrunner	posted 07-05-2005 06:37 PM ET (US) Do a search on this topic, we just had an extensive conversation regarding 90hp top speed with various prop pitches. Should be about 7-10 days ago. If you can't find it, I'll try looking for you.
bsmotril	posted 07-05-2005 09:48 PM ET (US) Found this one, but it is for a Dauntless 16 hull, and a Merc Motor, not OMC: http://continuouswave.com/ubb/Forum4/HTML/003623.html Nothing else within the last 10 days Bills
rumrunner	posted 07-05-2005 11:05 PM ET (US) http://continuouswave.com/ubb/Forum4/HTML/003499.html Title is deceiving, but a lot of prop pitch talk involving Montauks (I realize no Sakonnets, but good info)
bsmotril	posted 07-06-2005 10:29 AM ET (US) Thanks for the pointer, that was an excellent thread. BillS
Teak Oil	posted 07-07-2005 12:07 AM ET (US) Sounds like you are propped right as far as mph goes. Get a tach. My 1985 Evinrude gets 43-44 with two and some fishing gear, but I have a jackplate and ss prop. When I was mounted on the transom I got the same numbers you are getting now
Robob2003	posted 07-07-2005 09:58 AM ET (US) bsmotril, I'm running a 1966 Sakonnet with a 1980 100 HP Johnson turning a 17X13 stainless 3 blade prop, which is painted black, and on my GPS I run about 40 MPH at 5500 RPM. I don't like to run it at WOT so don't usually go much beyond 3000-3500 RPM and 20-25 MPH , a range it seems to like. It's old like me:-) Bob on Tampa Bay P.S. I thought I had an aluminum prop but the prop shop told me what it was when I took it in for ding removal.
bsmotril	posted 07-07-2005 10:20 AM ET (US) Do you know what the gear ratio is for the lower unit in your motor? BillS
Teak Oil	posted 07-07-2005 11:38 PM ET (US) All the old crossflows had 2:1 lower gears.
LHG	posted 07-08-2005 02:59 PM ET (US) My in-line 6 Mercs have 2:1 gears also, and with a 19" pitch prop, the prop chart shows 46-47 MPH at 5600 RPM. So you are probably running at maybe 5300 RPM.