need more negative trim

[randyray41]

I have a 78 Evinrude 70 hp mounted on a CMC pt130 power trim unit. I need some more down trim. I was thinking I could place some washers ( about an 1") behind the engine mounting bolts on the top to allow for more down trim. If this is done there will be a gap between the engine mount and trim mount plate.

Can this be done? I dont know if that will be safe to keep the motor securely mounted. Any thoughts or suggestions would be appreciated.

 

[interalian]

You can get transom shims. I have them on my rig and they do the trick. They're about an inch thick at the top, tapering to nearly nothing.

 

[randyray41]

I ordered a set of shims from CMC. I dont have any means to lift motor with a hoist, etc. Any ideas of how and what needs to be done to install them?

 

[Sea Rider]

For what precise purpose do you need to count with negative trim ?

Happy Boating

 

[Lightwin 3]

There should be a lifting ring on the back of the engine block. You can rent a portable engine crane from most tool rental places.

 

[randyray41]

I cant trim it low enough to keep boat from porposing(sp) at low speeds.

 

[flyingscott]

Is your trim pin in the lowest hole?

 

[randyray41]

yes it is

 

[kbait]

Can you transfer some weight toward the bow? Fuel tank..battery(s)?

 

[oldboat1]

A come-along and a sturdy overhanging limb is enough to lift the 70 out of the way. Not sure if motor mounting height is a factor, but guess it might be -- maybe mounted a little too high(?)

 

[interalian]

For what precise purpose do you need to count with negative trim ?

Happy Boating

In my case, the transom angle on my tin boat is too shallow and I couldn't keep the bow down. Good planing trim was only a skoche above full trim-in (yes, pin at min trim). Now I have a useable trim and good planing trim shows lowish in the "trim range" on the OE gauge. Now, I can trim it low enough to make the bow plow.