Go Back   TeamTalk > Maintenance Tips, How-tos and Refurbishing Topics > Engine / Drive Train

Reply
 
Thread Tools Display Modes
  #1  
Old 09-05-2018, 08:37 PM
DVW70 DVW70 is offline
TT Newbie
 
Join Date: Jul 2018
Boat: Mastecraft, 190, 1987, 351
Location: Northeast
Posts: 19
1987 Prostar 190 prop shaft diameter?

Is it 1 or 1-1/8?

I have an opportunity for a 2003 prop 13.25x16 for use in a pinch but its 1-1/8 diameter
Reply With Quote
  #2  
Old 09-05-2018, 08:48 PM
waterlogged882 waterlogged882 is offline
MC Master Poster
 
Join Date: Dec 2004
Boat: 93 190
Location: lake
Posts: 12,338
Quote:
Originally Posted by DVW70 View Post
Is it 1 or 1-1/8?

I have an opportunity for a 2003 prop 13.25x16 for use in a pinch but its 1-1/8 diameter
Could be either size with no information.

Just look and see.

Several ways to tell from looking at the boat.
__________________
John 14:6
Reply With Quote
  #3  
Old 09-05-2018, 08:51 PM
DVW70 DVW70 is offline
TT Newbie
 
Join Date: Jul 2018
Boat: Mastecraft, 190, 1987, 351
Location: Northeast
Posts: 19
Thought it was simple so I’ll put a caliper on it
Reply With Quote
  #4  
Old 09-05-2018, 09:02 PM
waterlogged882 waterlogged882 is offline
MC Master Poster
 
Join Date: Dec 2004
Boat: 93 190
Location: lake
Posts: 12,338
Quote:
Originally Posted by DVW70 View Post
Thought it was simple so I’ll put a caliper on it
Look on the face of the hub of the prop. The prop size will be stamped on it, including the hole size diameter.

Look on the tag of the transmission for the standard or the gear reduction option (power slot):
1:1 gear ratio = 1" dia

1.52:1 gear ratio = 1-1/8" dia
__________________
John 14:6
Reply With Quote
  #5  
Old 09-05-2018, 09:10 PM
DVW70 DVW70 is offline
TT Newbie
 
Join Date: Jul 2018
Boat: Mastecraft, 190, 1987, 351
Location: Northeast
Posts: 19
Well that settles it I know for sure it’s 1:1 - thanks for the hep!! DVW
Reply With Quote
  #6  
Old 09-06-2018, 09:57 AM
Strreamline Strreamline is offline
TT Enthusiast
 
Join Date: Aug 2016
Boat: 1988 Mastercraft Platinum Prostar 190
Location: Canada
Posts: 145
They sell prop shaft adapters to bring a 1" shaft up to 1 1/8". Some will say sketchy, but for an emergency basis it may not be a bad idea if the prop is free.
Reply With Quote
  #7  
Old 09-06-2018, 10:38 AM
88 PS190 88 PS190 is offline
MC Maniac
 
Join Date: Aug 2005
Boat: 1988 MC Prostar 190, 351 Ford
Location: Midwest
Posts: 4,358
Send a message via AIM to 88 PS190
Quote:
Originally Posted by DVW70 View Post
Is it 1 or 1-1/8?

I have an opportunity for a 2003 prop 13.25x16 for use in a pinch but its 1-1/8 diameter
So lots of issies there 2003 is probably splined vs keyed. Your 87 regardless of transmission would be keyed shafting.

1" shaft is a 1:1 ratio 13" diameter by 13" pitch
1.125" shaft is a 1.5:1 ratio 14" diameter 18" pitch.

The way this works is that for every 1 turn of the engine a 1:1 boat wants to move forwards 13" in the water but slips a bit. A 1.5:1 boat turns the prop less rotation but due to having 18" of pitch it wants to move forwards 12" but slips.

That amount of slip is reduced on a 1.5:1 boat because the prop is larger and turning slower.


Between 1987 and today the 1.5 ratio was deemed too steep and most every modern ski boat has a 1.2-1.4:1 ratio with less than 18" pitch
That larger 13.25x16 prop even if it were a 1" tapered keyed bore would load the boat down being both larger so less slippage and 125% steeper pitch.

Hope that helps.
Reply With Quote
  #8  
Old 09-10-2018, 06:45 PM
DVW70 DVW70 is offline
TT Newbie
 
Join Date: Jul 2018
Boat: Mastecraft, 190, 1987, 351
Location: Northeast
Posts: 19
Thanks for the great info. I purchased a 13x11.5 three places new style CNC prop (everyone said you need a puller a a spare prop) - boat definitely more pop out of the hole and interesting the 4 blade 13x13 the engine would hit 4950 and 45mph at wot now 4600 and 44MPH - something’s off a little but I’m not barefoot in and we saved the weekend - all is good...
Reply With Quote
  #9  
Old 09-10-2018, 11:00 PM
cbryan70's Avatar
cbryan70 cbryan70 is offline
MC Maniac
 
Join Date: Jul 2006
Boat: 1993 Prostar 205
Location: midwest
Posts: 4,652
Your motor should not be hitting 5k....
__________________
Quote:
Originally Posted by Hoosier Bob
She always misses me and when I turn her on it is hard to turn her off! She is MC and she completes me! She is the first ride that wants it as much as I do!
Reply With Quote
  #10  
Old 09-15-2018, 11:17 AM
DVW70 DVW70 is offline
TT Newbie
 
Join Date: Jul 2018
Boat: Mastecraft, 190, 1987, 351
Location: Northeast
Posts: 19
The teach is original and I can confirm accuracy but the 4 blade 13x13 WOT would show 4950 and the new 13x11.5 3 blade is happy and running well at 4600 dunno why. And getting the 4 blade fixed and adding cup to it to bring down the rpm regardless.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -4. The time now is 06:22 PM.


2018