| View previous topic :: View next topic |
| Author |
Message |
Chester
Joined: 04 Sep 2006
Posts: 1176
City/Region: home
State or Province: WA
C-Dory Year: 2005
C-Dory Model: 22 Cruiser
Vessel Name: Sold to lovely couple
Photos: Chester
|
 Posted: Sun Jan 05, 2014 3:17 pm Post subject: Outboard Engine Mounting Bolts - How Tight? |
 |
|
My research suggests the engine's anti-ventilation plate shouldn't be immersed while on plane. Ours are and I can raise the motors one notch without drilling new holes.
I doubt if that will be enough to raise the plate out of the water but we'll see if it helps.
My question is how tight do the engine mount bolts need to be torqued?
Don't wanna crush the core or have loose mounts.
Like Goldilocks porridge they need to be just right. |
|
| Back to top |
|
 |
Sunbeam
Joined: 23 Feb 2012
Posts: 3990
City/Region: Out 'n' About
State or Province: Other
C-Dory Year: 2002
C-Dory Model: 22 Cruiser
Photos: Sunbeam
|
| Posted: Sun Jan 05, 2014 4:12 pm Post subject: Re: Outboard Engine Mounting Bolts - How Tight? |
|
|
| Chester wrote: | My research suggests the engine's anti-ventilation plate shouldn't be immersed while on plane. Ours are and I can raise the motors one notch without drilling new holes.
I doubt if that will be enough to raise the plate out of the water but we'll see if it helps. |
I have the same situation - likewise I am going to raise the engine one "hole." (Another Brat with my same engine/mounting height already did this and reported favorable results.)
| Chester wrote: | | My question is how tight do the engine mount bolts need to be torqued? |
Good question and I will be reading the replies with interest. Right now it looks like my engine was put on with galvanized fasteners; I got ahold of some "stock" coated Yamaha fasteners and will use those. I wonder if there is a torque specification for the fasteners themselves? I suppose many people just do it until it seems "right," but I'd like to know more.
| Chester wrote: | | Don't wanna crush the core or have loose mounts. |
I hear you there. What I am going to do is remove the core in the way of the fasteners and replace with thickened epoxy. That way there will not be crushable (and/or "soakable") core there. Not that this means they shouldn't be torqued correctly, but at least I won't be tightening them against balsa (or other coring). |
|
| Back to top |
|
|
Captains Cat
Joined: 03 Nov 2003
Posts: 7313
City/Region: Cod Creek>Potomac River>Chesapeake Bay
State or Province: VA
C-Dory Year: 2005
C-Dory Model: 22 Cruiser
Vessel Name: Captain's Choice II
Photos: Captain's Cat
|
| Posted: Sun Jan 05, 2014 4:54 pm Post subject: |
|
|
The 90 ETEC service manual that I just got says to torque to 40 ft lbs. On other google search threads, it also says to use a backing plate. That seems like a good idea as does the undercutting and epoxy fill if you have totally removed the engine. I would hope that the original installer did that but I'd bet not.
Oh, and anti-seize stuff seems like a good idea if you ever intend to do it again.
Charlie
_________________
CHARLIE and PENNY CBRAT #100
Captain's Cat II 2005 22 Cruiser
Thataway (2006 TC255 - Sold Aug 2013)
Captain's Cat (2006 TC255 - Sold January 2012)
Captain's Kitten (1995 CD 16 Angler- Sold June 2010)
Captain's Choice (1994 CD 22 Cruiser- Sold Jun 2007)
Potomac River/Chesapeake Bay
K4KBA |
|
| Back to top |
|
|
Sunbeam
Joined: 23 Feb 2012
Posts: 3990
City/Region: Out 'n' About
State or Province: Other
C-Dory Year: 2002
C-Dory Model: 22 Cruiser
Photos: Sunbeam
|
| Posted: Sun Jan 05, 2014 5:18 pm Post subject: |
|
|
| Captains Cat wrote: | | On other google search threads, it also says to use a backing plate. |
That is a good idea, and I intend to add that (on the inside of the splashwell) when I remount the Yamaha (main engine). There are a few companies who sell them ready-made (TH Marine and Bob's Machine, for example).
When I re-installed my secondary engine on a Mini Jacker, I found that there weren't any "pre-made" plates for that mounting spacing (because it ends up being the Mini Jacker that one wants to "back," and it's not the same spacing as the engine clamps themselves), so I made a couple of oversized "fender washers" of fiberglass board, gelcoated them, and used those underneath the metal fender washers. One side benefit is that I was easily able to make one a bit of a "waxing gibbous" where the GRP washer came close to the curve of the splashwell. The extra backing is probably not necessary on the Mini Jacker, but I like having it anyway. |
|
| Back to top |
|
|
BrentB
Joined: 15 Jul 2006
Posts: 4420
City/Region: Greenwood
State or Province: IN
Photos: BrentB
|
| Posted: Mon Jan 06, 2014 8:13 pm Post subject: |
|
|
torque varies with bolt size
google yamaha rigging manual
For M12 bolt, it is 38 lb ft
M10 it is 27
_________________
Brent Barrett |
|
| Back to top |
|
|
Sunbeam
Joined: 23 Feb 2012
Posts: 3990
City/Region: Out 'n' About
State or Province: Other
C-Dory Year: 2002
C-Dory Model: 22 Cruiser
Photos: Sunbeam
|
| Posted: Mon Jan 06, 2014 8:40 pm Post subject: |
|
|
| BrentB wrote: | torque varies with bolt size
google yamaha rigging manual
For M12 bolt, it is 38 lb ft
M10 it is 27 |
Thanks for the info. I was able to find a 2012 Yamaha rigging manual for download (and did download it), but no luck on the 2002. At any rate, I doubt the torque that a specific year fastener can take would change, so I'll measure mine and go from there. |
|
| Back to top |
|
|
tpbrady
Joined: 08 Feb 2005
Posts: 891
City/Region: Anchorage
State or Province: AK
C-Dory Year: 2005
C-Dory Model: 25 Cruiser
Vessel Name: Bidarka II
Photos: Bidarka
|
| Posted: Mon Jan 06, 2014 8:51 pm Post subject: |
|
|
I didn't see it mentioned, but I have always used NYLOCK nuts on the bolts. That keeps them from vibrating loose lock washers not withstanding. If you don't use NYLOCKS, I would double nut the bolts for the same reason.
As far as motor height is concerned, I haven't seen any C-Dory yet where the motor wasn't too low when it was rigged by the dealer. I admit I haven't seen that many (6), but that's a pretty bad track record for "professionals" rigging engines.
Tom
_________________
Tom
22 Cruiser Bidarka 2004-2009
25 Cruiser Bidarka II 2010-2013
38 Trawler Mia Terra 2012-2015
42 Nordic Tug 2015-
28 KingFisher 2009-2014
14 Jetcraft 2000-
17 Scanoe 1981- |
|
| Back to top |
|
|
Captains Cat
Joined: 03 Nov 2003
Posts: 7313
City/Region: Cod Creek>Potomac River>Chesapeake Bay
State or Province: VA
C-Dory Year: 2005
C-Dory Model: 22 Cruiser
Vessel Name: Captain's Choice II
Photos: Captain's Cat
|
| Posted: Tue Jan 07, 2014 12:26 am Post subject: |
|
|
| tpbrady wrote: | I didn't see it mentioned, but I have always used NYLOCK nuts on the bolts. That keeps them from vibrating loose lock washers not withstanding. If you don't use NYLOCKS, I would double nut the bolts for the same reason.
As far as motor height is concerned, I haven't seen any C-Dory yet where the motor wasn't too low when it was rigged by the dealer. I admit I haven't seen that many (6), but that's a pretty bad track record for "professionals" rigging engines.
Tom |
Or locktite! |
|
| Back to top |
|
|
Foggy
Joined: 01 Aug 2013
Posts: 1579
City/Region: Traverse City; Northern Lake Michigan
State or Province: MI
C-Dory Year: 2014
C-Dory Model: 26 Venture
Vessel Name: Boatless in Boating Paradise
Photos: W B Nod
|
| Posted: Tue Jan 07, 2014 5:42 pm Post subject: Re: Outboard Engine Mounting Bolts - How Tight? |
|
|
| Chester wrote: | SNIP.... how tight do the engine mount bolts need to be torqued?
Don't wanna crush the core or have loose mounts.
Like Goldilocks porridge they need to be just right. |
Understandably, wanting your engine(s) to stay on your transom is a valid concern directly related to torquing the mounting bolts. Checking your owner's manual is a good place to start looking for "ft lbs" of torque. Of course, you'll need a torque wrench to read the recommended ft lbs of torque by exerting the appropriate pressure on the wrench.
In some situations, a torque wrench is not always handy or available. In these situations here in the boonies, I use my own "grunt torque" matrix which hasn't let me down yet. It goes something like this when knowing the required ft lbs:
5 - 25 ft lbs: 1 grunt
25 - 60 ft lbs: 2 grunts
60 - 95 ft lbs: 3 grunts
over 95 ft lbs: all the grunts you can muster, then check your pants
Using this, I've never lost an engine and rarely need to change clothes.
Aye.
_________________
Keep an open mind just enough to not let your brain fall out. |
|
| Back to top |
|
|
BrentB
Joined: 15 Jul 2006
Posts: 4420
City/Region: Greenwood
State or Province: IN
Photos: BrentB
|
| Posted: Tue Jan 07, 2014 7:29 pm Post subject: |
|
|
funny
 |
|
| Back to top |
|
|
|
Search
Private Messages
Profile
Log in
Register
Help
