Significant Fuel Burn Differential

YYZRC

Recruit
Joined
May 21, 2023
Messages
4
I have twin 6.2L with Bravo 3 sterndrives 2.2 ratio. Hill Marine 4x4 props new. 200 hours on motors. Replaced plugs, cap and rotor plus fuel filters in spring 2022 and the boat ran great.

Mid-summer 2022, I clipped a rock with the starboard drive which caused minor damage to the props and a chip out of the skeg. There was a drastic change in fuel burn on starboard side (+3gph vs port) which I attributed to the damaged props.

At haul out, I noticed that the gimbal ring was cracked so I replaced both transom assemblies. I also replaced the props and had the skeg repaired. When I mounted the drives, I swapped them so now the repaired drive is on the port side.

After all that, the port motor is now burning +3gph vs starboard. Also, the port motor won’t get above 3700 RPM when accelerating where starboard will do 4000. Once on plane both motors perform fine. I can only assume the drive is the cause but I can’t figure out what/why.

Thank you for any insights.
 
Last edited:

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
50,305
Did you inspect the drive gears, or just get the skeg welded?
 

YYZRC

Recruit
Joined
May 21, 2023
Messages
4
Thank you for the reply.

I split the drive so that the lower unit could be repaired. I did not inspect the gears but the drive shaft did spin freely by hand.
 
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