78 V150 lost high speed rpm

jetfixer

Recruit
Joined
May 29, 2006
Messages
1
I'm new at this and I looked at the previous posts, but just didn't nail it down. I have a 78 v150hp mercury s/n 5108663. The motor runs 5400 rpm with no engine complaints, but it won't charge the battery. I changed the stator bought off ebay and noticed the battery is charging now,also changed the switchboxes also ebay, problem now is at above 2000 rpm cyl 1,3,5 lose their spark. I swapped the stator leads red,blue to the opposite switchbox to see if the problem follows, ran it last night and all cyls seem to be firing but it seems to run rough at low speed and stalls at idle only get 2500 rpm but cyls don't lose fire like before. When set up like the wiring diagram it purrs like a cat at idle, just can't get above 2000 rpm. Could the stator high speed windings be bad on just the odd cyls?
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: 78 V150 lost high speed rpm

Could be the stator, could be the switchbox. Swap the switchboxes. If the problem moves to the even cylinders, it's the switchbox. If it's the stator, the odd ones will still act up.
 
Top