# CMC PLATE



## Puertoricoinshore (Aug 26, 2010)

Has anyone try this before, to put a plate on the cmc to raise the motor up. 
sorry the pic is kind of off.

































I will take the piece to the machine shop to cut 1/2" off so the two parts look like one. Any opinion please let me know.


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## HaMm3r (Dec 11, 2006)

I would be a little concerned that you don't have enough overlap of the two plates, basically you'd only have two bolts holding them together the way you've got the new piece positioned. If it were me, I'd get a larger piece and bolt it onto the back of the CMC so that it covers most of the existing plate and sticks up the extra few inches.

Otherwise, good idea!


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## AfterHours2 (Aug 2, 2010)

> I would be a little concerned that you don't have enough overlap of the two plates, basically you'd only have two bolts holding them together the way you've got the new piece positioned. If it were me, I'd get a larger piece and bolt it onto the back of the CMC so that it covers most of the existing plate and sticks up the extra few inches.
> 
> Otherwise, good idea!


X2. Definitely mount to the outside and cover the entire back of the cmc. This should give you plenty of support and also act as a fixed jackplate. Good idea..


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## Puertoricoinshore (Aug 26, 2010)

[smiley=1-mmm.gif]
Thank you guys. Defenetly a better idea to use a bigger plate on the outside. 
Thanks!!!!!!!!!!!!!


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## Puertoricoinshore (Aug 26, 2010)

Took the plate to the machine shop this after noon. Hope by the end of next week the piece is done and i can try the motor. Going to go with this piece for now and do some test if not plan b will be the wining ticket. Will see.


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## HaMm3r (Dec 11, 2006)

Well good luck. Just make sure your motor is bolted or chained to something else besides that add-on plate. If the torque tears that plate loose, I'd hate for your motor to take a swim.


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## Puertoricoinshore (Aug 26, 2010)

I am thinking of usisng another 1/2"on the back of as you guys said and install both.


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## Puertoricoinshore (Aug 26, 2010)

After 7 months an update on the piece.
































where it seats with the plate








with out the plate


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## firecat1981 (Nov 27, 2007)

is it sandwiched between 2 plates, or is it still just those 2 little bolts holding it on?


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## Puertoricoinshore (Aug 26, 2010)

The cut curve is 1/2" deep living 1/2" plate and it seat on top the cmc making the two parts into one. The two 1/2" nuts and bolt on the corners holds the two pieces together really strong and then the motor to the top holes. I am going to use 1/2"aluminium bar from the motor holes to the cmc to reinforce. But is not really needed at all.


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## Puertoricoinshore (Aug 26, 2010)

Here is how it seats


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## HaMm3r (Dec 11, 2006)

Well, the torque on those two bolts is going to be pretty severe I'd think, but if you're happy with it then good luck to you. It looks good, I'd just be afraid of snapping that plate off and losing the whole motor.


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## Puertoricoinshore (Aug 26, 2010)

I understand your point. But that motor was hold to the cmc for the past five years since the owner boughted with two not even the four 3/8" ss bolt with no issues. Now with the remodeling i change them to 1/2" and use the four. But defenetly in the end i am going to put reinforcements. Ohh and that aluminium plate is the stronges aluminium alloy for the application. Thanks HaMm3r!!!!!


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## Puertoricoinshore (Aug 26, 2010)

Right now the only issue with the plate is ventilation. I did put the cavitation plate on the motor with the bottom of the transom. And the first test with the aluminium propeller 11 3/8 x 12p and tabs, no running at all only ventilation. Then test with another propeller 11 5/8 x 14p ss prop and no tabs. better hole shot and good top end speed with two persons and full tank of gas. To me what we need is another prop 4 blade or cup the ss prop. So we can get more bite on the water.

If you have any knowledge on the issue you be more than welcome


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## DuckNut (Apr 3, 2009)

If you are getting ventilation then you need to drop the motor, add a compression plate. A different prop is not necessarily the answer.

Also, your comment on how the previous owner mounted the motor worked because the bottom of the motor bracket had the transom/jackplate to push against. What you have done is to remove this solid point of resistance and changed the fulcrum point which will create tremendous amounts of stress on those two bolts. If it were me I would try to fit a couple more on there. It appears you have room to do this at the point near the curve you ground out.


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## HaMm3r (Dec 11, 2006)

> ...But that motor was hold to the cmc for the past five years since the owner boughted with two not even the four  3/8" ss bolt with no issues. Now with the remodeling i change them to 1/2" and use the four...


Fine, except the four bolts are through the new plate, not the original CMC mounting surface, so ultimately they're doing nothing to strengthen how the motor is attached. You've still just got two bolts holding the plate which holds the motor, and because of the added height you've essentially created a lever which will put far more force on the two connecting bolts.

Look, it's a great idea, but that weak junction just screams trouble. At least try to put an extra set of bolts through the bottom of the motor clamp bracket and the CMC plate. Or go pick up a bigger piece of aluminum and do it right, as suggested earlier.


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## Puertoricoinshore (Aug 26, 2010)

After a bunch of testings the plate does what it supose to do. But when you have more than 2 people plus gear, baitwell (28gls of water), 12gls of gas, 10ft cast net is defenetly under power. So know my buddy the owner was waiting for and excuse to change the motor and this one work great for him. So in the next couple of days a motor upgrade to a yamaha 60hp 2007 same setup (manul start etc). Pics coming soon!!!!!!!!!!!!!!!!!


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## Puertoricoinshore (Aug 26, 2010)

Whent on thursday to pick up the 60hp 2 cycle 2005 yamaha. Rigth know moto is already mounted, but took the carbs out to clean them and install new kit. Pics coming soon


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## Puertoricoinshore (Aug 26, 2010)

Yami 60 hp 2005


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## AfterHours2 (Aug 2, 2010)

Nice to see you got some more power. Whats the weight difference between the two?


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## Puertoricoinshore (Aug 26, 2010)

I was looking in the net fir specs and the 60hp is 233lbs and the 40hp is 160 -170 not sure. When we install the motor we did not notice any difference at least on the trailer. The real issue is that this one is long shaft.


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## AfterHours2 (Aug 2, 2010)

That sux its a long shaft. You are probably going to either have to build up the transom, possibly shim the motor up or ??? Putting a jack plate on top of the cmc would be out of the question if it were me. Way too much setback. Can you raise the cmc a few inches and do the same with the outboard? Hard to tell without close up pics..

It sure would be nice if the new motor had factory trim. Then you could ditch the cmc all together and go with a manual jack plate. That would be ideal...


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## Puertoricoinshore (Aug 26, 2010)

Better pics

















Right now is sitting on the 3 hole from top to bottom still have one more hole to go up.


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