Need help diagnosing Evinrude 9.5 problem

[david-bartlett]

quote outbdnut2:

quote fleetwin:

Yeah, these engines don’t have a lot of power/top RPM….They start easy, idle nice, and are smooth, but aren’t going to win any races….
Try to take a video of the engine running on the boat if you can…

Yeah – these 9.5s were rated at the powerhead, as were the Mercury 9.8s. I’ve found these two motors perform about the same, and the Johnson 9.9s rated at the propshaft from the late 1980s and the Merc 9.9s from 1986 up will plane boats and run circles around the 9.5s and 9.8s. I’ve had them all on my 14′ aluminum rowboat for comparison.
Dave

That 9.8 Merc you had must have been running pretty poor if it ran about the same as the 9.5.

I ran the same motors on the same aluminum boat and the Merc was way more motor than the OMC.

Like Mumbles said the 9.5 is a fishing motor.

[fisherman6]

quote david bartlett:

quote outbdnut2:

quote fleetwin:

Yeah, these engines don’t have a lot of power/top RPM….They start easy, idle nice, and are smooth, but aren’t going to win any races….
Try to take a video of the engine running on the boat if you can…

Yeah – these 9.5s were rated at the powerhead, as were the Mercury 9.8s. I’ve found these two motors perform about the same, and the Johnson 9.9s rated at the propshaft from the late 1980s and the Merc 9.9s from 1986 up will plane boats and run circles around the 9.5s and 9.8s. I’ve had them all on my 14′ aluminum rowboat for comparison.
Dave

That 9.8 Merc you had must have been running pretty poor if it ran about the same as the 9.5.

I ran the same motors on the same aluminum boat and the Merc was way more motor than the OMC.

Like Mumbles said the 9.5 is a fishing motor.

I was thinking the same thing when I read this. I have a Merc 9.8 with a prop that is chowdered beyond recognition and it will handily outrun a OMC 9.5 on the same boat. I still have that beat up prop on it because I can’t get it off the shaft to replace it.
-Ben

OldJohnnyRude on YouTube

[outbdnut2]

Thinking about it, the mid-1970s Merc 9.8 I fixed for a friend did have about a million hours on it, so compression could be down some.

Dave

[titantn]

quote crosbyman:

maybe I missed it….. what was the basic cause of all this grief….coils carb wires crud, ……? …and tell it to that original mechanic who had no faith in oldies 😆

I’m not 100% sure what the issue was because I replaced everything electrical. Even though the coil packs physically looked good, I suspect it might have been that. But now I have new packs, wires, points, condensers, plugs.

When I took it to the lake this weekend I think it would have started on one pull if I’d had a good angle. I repositioned and it started on the next pull. Idled great and really had no issues. This was after sitting for a month.

I concur with the overrated power. It runs great, but I have so much water friction with my inflatable dingy that it doesn’t stand a chance of getting on plane.

And yeah, I do hope to see that mechanic again. Thanks again for your help.

[Author]

Posts