1970 Johnson '85 - which prop/tilt/trim?

[edandq]

Greetings all, a couple questions. I have this engine on a 1970 Starcraft Super Sport (aluminum), and use it for pulling my kids on the tube, messing around, etc.. what's a good prop to get it up on plane quick. It does great once on plane, but not a good hole shot.<br /><br />Also, I have to hand lower and raise this engine. What a pain... Can I add power tilt, without killing my pocketbook?

 

[Cricket Too]

Re: 1970 Johnson '85 - which prop/tilt/trim?

What pitch prop do you have on it now and what is your WOT rpm?

 

[Hooty]

Re: 1970 Johnson '85 - which prop/tilt/trim?

First the prop:<br />You can most likely reprop and get a better "hole shot", but before we can offer any advise, we'll need to know a few things.<br />First, what diameter and pitch prop is on it now. Second, how many rpm and third, how is the engine trimmed now. Where is the 'cavitation' plate in relation to the bottom (keel) of the boat and which trim hole do you have the pin in.<br /><br />Tilt & trim? Probably. I just noticed, that's a '70 engine but something should be available, either a factory or aftermarket set-up. Check ebay.<br /><br />c/6<br />Hooty

 

[edandq]

Re: 1970 Johnson '85 - which prop/tilt/trim?

Okay, so I'm a little new to boating. Learning as I go though Okay, so what is WOT RPM? How can I check RPM. I don't have any, I mean any, gages. Also, how do I check what pitch/size my current prop is? How do I check where the caviation plate is relative to the bottom of boat? Simply lower the engine? I know this is the engine that came with the boat when new. Also the trim hole, I can look at which one it's in, no problem, but didn't even know that's that big pin was for trimming the engine...

 

[R.Johnson]

Re: 1970 Johnson '85 - which prop/tilt/trim?

They made a power tilt in 1970, but not tilt & trim . If your prop is an OMC,the size will be found on the hub, under the prop nut spacer. You will need a tach to check RPM. There are after market tilt & trim units. That may be difficult on your engine because you also don't have tilt tube steering. You also have the seperate mounting brackets.

 

[edandq]

Re: 1970 Johnson '85 - which prop/tilt/trim?

What do you mean I have don't have tilt tube steering and I have seperate mounting brackets?

 

[R.Johnson]

Re: 1970 Johnson '85 - which prop/tilt/trim?

If you look at the way the engine is mounted to the transom, you will see a bracket on each side of the engine. These are bolted to the transom, the engine slides down into these brackets, and the engine is held in place with a bolt on the top of each bracket. Tilt tube steering has a hollow tube that the engine pivot's on. The steering cable on later engines runs through this tube, and the tube act's as an anchor point, as well as a guide. Your engine has a transom mount anchor point. This does not lend well to a after market tilt & trim, as these units' have a certain amount of set-back. I'm not saying it can't be done, but it has to be safe.

 

[edandq]

Re: 1970 Johnson '85 - which prop/tilt/trim?

Okay, I think I get it. But, I would rather retrofit my with original tilt if it was available. I don't even know. As for the steering, My cable follows the side of the boat, comes through a hole in the transom where there is a standout bracket holding the outer sleave, and then the inner portion of the steering attaches to a bar type area in the lower front point of the engine. <br /><br />Another point then, so you're saying I can remove this engine without removing all the brackets attached to transom?<br /><br />Oh, and to answer another question, my pin is in the second (of five) hole from the transom.

 

[R.Johnson]

Re: 1970 Johnson '85 - which prop/tilt/trim?

In my post I said the tilt tube is what the engine pivot's on, I meant what the engine tilts on. On removing the engine there is a stainless bolt on top of each bracket, you unscrew these and lift the engine straight up. The steering cable anchor on your transom is what I was talking about. It limit's on how far back you can set the motor. If you get a chance to look at another boat with a newer engine, the picture becomes much more clear. As I said before, you may find a OEM tilt for you engine, but not trim.

 

[edandq]

Re: 1970 Johnson '85 - which prop/tilt/trim?

To answer an earlier question, it says on the hub of the prop 0157B, what does that mean? It's stamped on the outside of it...