max RPM of 1977 115 mercury and whats final drive ratio?

kcseasprite

Cadet
Joined
Sep 17, 2009
Messages
16
I need to know what the max rpm is for this motor and the final drive ratio example: 2:1,2.07 etc. Also would like to know max timing for this motor. Thanks.
 

Jeff_G

Petty Officer 2nd Class
Joined
May 1, 2005
Messages
179
Re: max RPM of 1977 115 mercury and whats final drive ratio?

19-21* 5800 rpm 2 to 1
 

daveswaves

Ensign
Joined
Mar 22, 2002
Messages
901
Re: max RPM of 1977 115 mercury and whats final drive ratio?

19-21* 5800 rpm 2 to 1
Hi Jeff, my book has the 77 1150 with a max at 5300, the 77 1500 is a max at 5800. From experience, the 77 1150 just cant gulp enough air to make 5800. I know the innards would take it no problem but....
 

emckelvy

Commander
Joined
Jan 16, 2004
Messages
2,506
Re: max RPM of 1977 115 mercury and whats final drive ratio?

5300-5500 is probably a more realistic rpm for an 1150 I reckon. My old 1350, on the other hand, had no problem spinning the tach right up to 6000! Pretty interesting on a 15'-9" Super Sidewinder!!!

Here's all the info you'll need to get your 1150 Tower of Power in perfect tune:

http://forums.iboats.com/showthread.php?t=168855

HTH..........ed
 

Jeff_G

Petty Officer 2nd Class
Joined
May 1, 2005
Messages
179
Re: max RPM of 1977 115 mercury and whats final drive ratio?

I should have expounded more. The 115 was rated for a full throttle of 5300 as Dave correctly pointed out, in the 1970's.
However I found if you prop it for 5800 you will have a much better all around boat. Propping will allow the 5800 no problem.
The 150 I recommend 6,000. The XS was rated for 6300 and I would say leave them there or even a little less, more of the 1500 specs.
In all of these engines lower the timing to around 19* with todays fuels and go up one jet size. Your motor will thank you.
 
Top