Inboard outboard air cooled engine

guy74

Senior Chief Petty Officer
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Jul 12, 2007
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794
Re: Inboard outboard air cooled engine

You can cut off the crank if you need to. I've run motors with cut down crankshafts with no problems.
 

maxum247

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Re: Inboard outboard air cooled engine

You can cut off the crank if you need to. I've run motors with cut down crankshafts with no problems.
Ok, then it is possible! Was wondering about that!:)
 

MikDee

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Re: Inboard outboard air cooled engine

Here's the T-bolt clamp it's stronger, heavier then a screw type worm gear clamp,,, plumbers use them on fernco (no -hub) fittings, so they should be readily available at Home Depot, Loews, or a plumbing supply, they use a hex head wrench to tighten.

By the way, I'm just here to throw idea's out to ya, to guide you if I can, and tell you how, or why, I think they'd work, no hard feelings if you experiment, and do it your way ;) after all you're the guy with the plan, ambition, and doing all the work, to make this happen.

Also, is there anyway you can make this work by cutting the L.U. shaft instead of the motor shaft?

I figure you should be able to do 20mph at least with this combo. :D

Oops! forgot the link: "http://www.hosexpress.com/clampsandtools/clampsandtools.htm"
 
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maxum247

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Re: Inboard outboard air cooled engine

Lower unit shaft can't be cut any shorter!

Do you really suppose that it could get that kind of speed with 221 pounds of me and gear aboard? I was willing to be happy with the fact that it might plane! Man that would be great coming into the dock and bystanders saying man that thing moves right along what kind of power (looking in to see the Briggs) "jaw drop" a riding lawm mower engine? Head scratch! That's what makes this fun for me is the thought of the conversations to come! Can't wait!
 

MikDee

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Re: Inboard outboard air cooled engine

Do what you gotta do with the shaft, to get whatever height you need, just make sure there's no way to get around it first.

Hell yah! I think it would take 15mph to plane off, it should do that, and a bit more.
 

maxum247

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Re: Inboard outboard air cooled engine

Ok, then if that's the case will the tiller steering be practicle? Seems there might be a lot of force there, might need to consider cable and pulley steering with a steering wheel. What do you think?
 

Lone Duck

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Oct 17, 2007
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Re: Inboard outboard air cooled engine

Ok, then if that's the case will the tiller steering be practicle? Seems there might be a lot of force there, might need to consider cable and pulley steering with a steering wheel. What do you think?
Will the 1 1\2 " left on the crankshaft be enough for your coupler? I think cable steering would be best. I don't like the idea of being too close to that engine with the top open spinning fly wheel and a HOT exhaust . And your son in the boat. Maybe shim the engine up till after your 1st test before you cut the crank. turn the engine to get at the spark plug and aim the exhaust opening to the stern. Then you can direct the 90 for the oil drain where ever you want. Hang your rudder off the stern with a tiller handle above top of transom for your cable steering. Then use wheel or joy stick . This rig is going to be beautiful. Are we having fun yet? I am but I ain't getting my hands dirty.
 

MikDee

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Re: Inboard outboard air cooled engine

Will the 1 1\2 " left on the crankshaft be enough for your coupler? I think cable steering would be best. I don't like the idea of being too close to that engine with the top open spinning fly wheel and a HOT exhaust . And your son in the boat. Maybe shim the engine up till after your 1st test before you cut the crank. turn the engine to get at the spark plug and aim the exhaust opening to the stern. Then you can direct the 90 for the oil drain where ever you want. Hang your rudder off the stern with a tiller handle above top of transom for your cable steering. Then use wheel or joy stick . This rig is going to be beautiful. Are we having fun yet? I am but I ain't getting my hands dirty.

I agree with Lone Duck on all this, finding or making a rudder to mount in the rear most bottom sounds difficult, especially to make it seal under water, a tiller handle off the rear close to the transom, is your best bet, a steering wheel can be added, but this gets a bit more complicated. Then you'll need cables to pulleys mounted in the rear corners, and also wherever you're gonna mount the wheel? I was also thinking all along, if you turned the engine 90* so the spark plug is clear, and the exhaust went straight back, maybe better if possible.
 

MikDee

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Re: Inboard outboard air cooled engine

The tiller rudder will not be hard to turn atall, I'd go that way, but take note a steering wheel needs a sturdy center console, or a fabricated 1/2 center deck mounted to the rightside of the boat, but either one need to be built into the boat, and either fastened to the front of the rear seat, or back of the center seat for strength, and remember to hide the cables, & pulley system, or get them outta the way, a 1/2 center deck fastened to the right side, will get them out of the way. A lot of extra work if you want to take it on?

When you think about it, if need be, the higher you mount the motor really won't matter much, because the powerhead of an outboard is usually above the transom anyway.
 

maxum247

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Re: Inboard outboard air cooled engine

Mount the engine higher it is! This will give me more room under the engine to make my connections and do repairs!
 

MikDee

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Re: Inboard outboard air cooled engine

I would recommend 3/4" galvanized pipe for the tiller, with a 90* elbow at the top, and sliced on the bottom to slip a rudder (of some type) in between than bolted thru, or welded on. They make sidewall pipe support loops, that attach to a small rectangular base with 2 holes in it (with a short piece of 3/8" threaded rod in between) to mount to the transom, to slip the tiller shaft into. You would need a 3/4" pipe coupling somewhere near the top, to hold the tiller assembly up off the transom, by resting on top of the upper pipe support, instead of going thru it.

Unless you have other idea's?
 

Nos4r2

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Dec 12, 2004
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Re: Inboard outboard air cooled engine

Pipe it out the back and call it a rooster tail with all the speed I'm going to get from this thing! Actually the impeller and pump have been removed! But I will still need to make a cover plate to keep the water pressure from driving the water up thru won,t I? Didn't think of that! That would be embarassing wouldn't it! Hey! Thanks!

Might be worth simply cleaning off your chosen lower unit and filling the water intakes and any other holes with a good epoxy adhesive? It'd be less likely to leak than a mechanical seal around the driveshaft.
 

maxum247

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Re: Inboard outboard air cooled engine

Will the 1 1\2 " left on the crankshaft be enough for your coupler? I think cable steering would be best. I don't like the idea of being too close to that engine with the top open spinning fly wheel and a HOT exhaust . And your son in the boat. Maybe shim the engine up till after your 1st test before you cut the crank. turn the engine to get at the spark plug and aim the exhaust opening to the stern. Then you can direct the 90 for the oil drain where ever you want. Hang your rudder off the stern with a tiller handle above top of transom for your cable steering. Then use wheel or joy stick . This rig is going to be beautiful. Are we having fun yet? I am but I ain't getting my hands dirty.

Having second thoughts on cutting the crank myself. After looking closer I don't think I will need to, but it's nice to have the option!

Thinking on useing a metal spaghetti strainer turned upside down to take care of the flywheel leaving the back third open!:D

Exuasht: Louvered grill of some sort to disapate the heat!

Don't know about beautiful! I'd settle for functional!

Fun? yeah! Don't worry I get greasy enough for both of us when I work on it!:)
 

MikDee

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Re: Inboard outboard air cooled engine

Hey maxum, For the exhaust couldn't you use that heatproof type heavy tape wrap covering they use on race car headers.
 

maxum247

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Re: Inboard outboard air cooled engine

Hey maxum, For the exhaust couldn't you use that heatproof type heavy tape wrap covering they use on race car headers.
I've seen it used, and I understand it works pretty well!:cool:
 

Lone Duck

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Oct 17, 2007
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Re: Inboard outboard air cooled engine

Yeh but where does the heat dissapate too? Burn out muff? Hmmmm who says the tiller has to be in the centre? How bout off side of the exhaust ?(width of the motor port or starboard.) Must be a reason why it is in the centre isn't there ?
 

maxum247

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Re: Inboard outboard air cooled engine

Mufflers are low cost, couple a season no big deal! Or is it?:confused:

Steering might take on a whole new meaning with the rudder mounted to the side!:eek:
 

MikDee

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Re: Inboard outboard air cooled engine

Trust me, steering works better on center, besides who's using a muffler? :D It sounds better with just a piece of pipe on there, the longer the better, it mellows it out.
 

Lone Duck

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Re: Inboard outboard air cooled engine

Well now, I suggest we all step back and let you think over all these idea's . Let us know how you think this is going to go together. Of course we will all have something to say about it. But the final choice of course is yours.
 

MikDee

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Re: Inboard outboard air cooled engine

Here's a common readily available reasonable muffler to screw onto 1" pipe at the end, (I'm guessing that might be the standard size exhaust port of a 12hp motor 1" I.P.S., instead of the smaller 3/4" I.P.S. outlet on the B&S 4-5hp motors) in case you need to throw one on.

"http://www.amazon.com/dp/B000UGVD2I?smid=A1IZCISXTFZ9OX&tag=dealtime-tools-20&linkCode=asn"
 
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