Penn Yan Tunnel Drive Exhaust Problem

Jorem

Recruit
Joined
Sep 17, 2007
Messages
3
The cowlings on my twin tunnel 26' Vindicator were cracked and losing their chaulking. I purchased new cowlings and mounted them.

Now I am experiencing a significant decrease in power. Both engines were rebuilt this summer and ran at 35-3700 rpm @ 24 knts. Now the engines struggle to get to 1500 rpm and I can't get to plane. The only change I've made is to replace the cowlings and to seal them tightly against the transom and the transom plates. The engines act as if the exhaust has is being restricted.

Looking at the exhaust ports, they do seem small. And I've noticed that the transome plates are tappered toward the transom. In fact the tapper is so large that 1/2 to 3/4 of an inch of chaulk is needed to fill that space.

Should I NOT chaulk the cowlings to the transome plates? Has anyone run into anything like this before?
 

SpinnerBait_Nut

Honorary Moderator Emeritus
Joined
Aug 25, 2002
Messages
17,651
Re: Penn Yan Tunnel Drive Exhaust Problem

Welcome to iboats.
I take it you are talking about inboard/I/O engines so I will move this to the Mercruiser, Volvo and OMC I/O or Inboard Engine Problems forum for you.
 

Jorem

Recruit
Joined
Sep 17, 2007
Messages
3
Re: Penn Yan Tunnel Drive Exhaust Problem

I would like to delete this thread as I have started another with pictures. How can I do this? I have followed the "Edit" buttons but I am unable to find a delete button.

Also, if you read my new thread and see my pictures you may want to post in some other more appropriate place.

Thanks for looking this over.

Joe
 
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