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My 16.5ft. crestliner came with a 70 hp Evinrude. It has power tilt but no trim. I would definitely like to add trim to this setup to help my performance.

This fall it was running right on 30MPH with two people, full tank of fuel and gear. According to the rpm guage it was hanging right around 5000rpm at full throttle I didn't think this speed was too bad but felt it could be better.


My options are add a trim unit and prop change. Question is, do I just have to add the proper unit to the outboard to do this

Here is a pic of the setup currently



Would I be better to just do a prop change and wait to see what difference this makes? Current prop is an aluminium 13 1/4 x 17

Anyone have a similar engine and can tell me what speed/rpm they are getting?

thanks

Joe

Hey Jale,

I might be mistaken here, but I believe your set up acts as both tilt and trim. I friend of mine has a 60 hp Merc with the same set up as you and he seems to trim just fine. Try lowering the pin down a couple of holes.

Peppino

Peppino,

That is what I currently do now. I just want the ability to trim it while moving. Leaning over the back moving that pin is not fun in 2 or 3 foot waves

Joe

Doesn't that cylinder raise your motor even when you're motoring? From your picture, it seems that it will raise beyond trim? My power tilt and trim is finished on my 70 Merc, I'm considering the CMC t/t unit. That also has a similar set up as yours , one main cylinder.

Peppino

Peppino

It will currently raise/lower the engine at low rpm, probably 1000rpm and below. Anything above idle/trolling speed it will not.

I guess it is possible that there is a malfunction somewhere.

Joe

RPM's should be around 5500. Maybe a prop change in size.

roughrider out

I'm no mechanic but, it sounds like your hyddraulics aren't doing what they're supposed to. In this case, that cylinder do-hickey thing-a-ma-bob.

Perhaps you need a new one of those or, the motor that actually activates the trim.


Where's Mikey when ya need him ...... Ya I know, I know...

Roughrider,

So you think my best bet would be to first drop down to maybe a 13 1/4 X 15 prop That would definitely increase the rpm but would it not also decrease speed?

Thanks

Joe

jale6666 wrote:Here is a pic of the setup currently



Would I be better to just do a prop change and wait to see what difference this makes? Current prop is an aluminium 13 1/4 x 17

Anyone have a similar engine and can tell me what speed/rpm they are getting?

thanks

Joe

Hi Jale....

My set up looks the exact same......, except an 85 evinrude....

I see one problem right away.......

That long "rusty" looking pin across the bottom of your motor support...

Slide it out, ....and put it in the last "hole" (the one closest to the transom)

With the pin where it is, .....you are losing most of your trim travel....

The trim and tilt are two separate systems, ....there's a switch on your throttle, ...connected to a valve on your tilt, .....when you pass a certain RPM...., this switch opens the valve, ....and drops your motor to the "top of your trim travel" (it's supposed to do that, .....so you don't accidently try running full throttle, ...with your prop half out of the water)....

Think about it, ...if your motor is tilted way up........the prop is angled downwards.......So If you gun it, ......where's the prop trying to take the back of the boat....., not a good thing, ...unless you're a submarine.....

This link may help explain it better, different problem, ...but same sort of thing........

http://www.fish-hawk.net/hawktalk/viewt ... hydraulics

If you're not sure what I mean about the pin, .....I'll try and get a pic of mine up later, ....if I can get to it.....

Hope this helps......

skooter.....

Here's the pin I'm talking about......





I found an old pic, ...which sorta shows where the pin is on mine, .....if you look closely.....



Move your pin to the back hole, ...and you will be able to trim your motor up and down through all that extra space......

The only thing I just thought of, .....maybe someone put the pin way up there, .....cause the trim system really is busted.....

You won't know though, ....till ya water test it......

Good Luck.....

skooter......

Thanks for the great info guys,

Skooter.... The reason the pin is out so far is I placed it there. When it was in tight to the transom the boat plowed a bit of water. The unit would not adjust when under power. It will only adjust when down around 1200 or less rpm.

By what you describe it sounds like a motor is not working properly...valve sticking possibly?

I was under the assumption that this was a power tilt only unit.


let me know what you think

Joe

You aren't meaning raising and lowering your motor are you?
If so, you need a jackplate, not T&T.

BTW, if you get 40mph, you'll likely bang on.

M.T.

jale6666 wrote:Thanks for the great info guys,

Skooter.... The reason the pin is out so far is I placed it there. When it was in tight to the transom the boat plowed a bit of water. The unit would not adjust when under power. It will only adjust when down around 1200 or less rpm.

By what you describe it sounds like a motor is not working properly...valve sticking possibly?

I was under the assumption that this was a power tilt only unit.


let me know what you think

Joe

Geeze, ......I'm not sure what to tell ya John....

From your pic, .....your set up looks exactly the same as mine.....

This is the manual that came with my boat.....





I know it's not specifically for your motor, ...but I'm thinking that aspect of it, ......would be the same....

I scanned a page dealing with the tilt/trim interaction....



I split the page in two, to make it easier to read...





I have a "generic" manual I keep at work, ......I got it cause it covered my old 40hp evinrude, .....but it also covers your motor, and even the motor I have now.....


I'll see what it has to say about it tomorrow, and let ya know......

Still tryin' to help.........

skooter

Bill....no I'm not trying to raise the engine..just trim it out for a better/smoother/faster ride. Not sure if it'll hit 40mph but should run mid-thirties at least

Skooter...My setup doesn't have those trim pistons. Looks like It'll be a whole new unit to get it set up properly. thanks for the help and keep me posted if you come up with anything else

Joe

Hi Jale....

Not much success today.....

This manual does explain the "operation" better though




I'm getting the impression that the trim cylinders are incorporated inside the main centre cylinder, .....using the same piston, .....so you won't see anything from looking at it, .......maybe

I tried to snap a couple of pics when I got home, ...but everything is pretty much hidden with the motor down ....





It's kinda difficult too, when it's almost pitch black and you can't really see what you're shooting....

I was really hopin' for an "exploded" view somewhere in the book, that showed all the parts, ....and where they fit, ...etc, ...etc

I obviously haven't found one yet, ...but I'll keep looking....

If nothing else, ...next time the boat is out, ...I'll snap some "good" shots with the motor up, ......

And, If nothing else, ...again, ...at least this keeps my mind off the weather, ....sort of.....

skooter ......