Topic: GL1100 engine, in a BOAT!? can someone field a question about those motors?

[oddballmotorsports]

another harebrained idea from the Oddball labs    build a jet boat, use a goldwing engine.  anyways,  this might not amount to anything,  but working it out on paper to see.  first hurdle, getting a pto made up that bypasses the transmission.  but since I've never owned a GL I don't know what I'm looking at.  there seems from pictures on the web, that there is something driven off the back of the crank, so my question is, what lives inside the circled nub?  Looks like an overrunning clutch,  or idunno.  since that's right off the back of the crank, and on center, it would make a good place to fab up a pto to run a 1:1 shaft to a jet pump. 2nd option, the clutch basket.  but the problem with that is its down low so the motor would have to be high up to make that work.  so can anyone tell me whats inside that nub?

[eigenvector]

Can't give you a definite answer - but if you search GL1100 starter, a couple of decent pictures of the back of the engine come up.  One of them looks promising as the area you're looking at.

[jgger]

Sounds like someone has too much time on their hands! Haha!

I don't know about the technology inside  the GL motor, but I'm thinking if you used the regular output shaft and the Trans the lower gearing could maybe pull 2 pumps? They would turn a little slower, but maybe produce less cavitation.

You are definitely a sick puppy and this will be cool to see how it comes out. Please keep us posted and good luck.

[oddballmotorsports]

Can't give you a definite answer - but if you search GL1100 starter, a couple of decent pictures of the back of the engine come up.  One of them looks promising as the area you're looking at.

the starter has a chain that hooks to the stater basket,  its not that,  at least i think its not...

[333]

Seems to me that 1:1 is somewhere between 4th and 5th gears.  Much easier to take the power from the shaft, over figuring out how to seal the crankcase after removing the transmission.  Also, keeping the clutch gives you a way to have a neutral.

[oddballmotorsports]

the biggest problem (that I see so far im sure there's many) is that if I were to use the output shaft, is the engine would be offset 4"ish in the boat,  it would be the easiest, and most ideal because of all the gear choices,  but I don't know enough about weight distribution in a boat to say if this is okay,  I think I could even it out on the opposite side with something,  that's an option too.  it would definitely be the cheapest as well.  as far as operating rpm's the gl1100 makes peak power at 8k where the Yamaha from the ski that has the pump I'm looking at, makes it at 7,  so 1:1 or a slight reduction like 4th gear might work perfect.  there's also the idea of a small supercharger, and degreeing the cams to bring the powerband down If I wanna get really crazy. basically take all the "gee whiz" stuff from the 70s jet boats, and have them, only smaller..  I think its a really slick idea lol

  I think I figured out what that nub is.  on the older models, it was where the kicker went, so, older kick start housing, gutted with an output flange, or shafted welded to it could work too,  as far as neutral,  never seen a jet with neutral, I don't think id need it..  but still nice to have..  another really neat idea, reverse,  not to reverse the boat, (that's done by redirecting thrust backwards)  but have it for an option, if something plugs the jet intake, pop it in reverse and possibly blow what ever is clogging it back out the intake   but reverse so I'm told is only found in the 1800's which are out of my price range...

[jgger]

Another thing to consider is the rotation direction of the motor vs. the pump.

The offset you mentioned could be corrected with a flat drive belt if the motor and pump rotate the same direction. If they rotate in opposite directions, then you could use a gear setup.

[2wheels]

What about a harley style engine?  No transmission required so less weight.
There not liquid cooled, so that would be a problem.

[333]

I believe the reverse in the 1800 is powered by the starter motor, not the engine.  Besides, the intake grate rarely clogs, unless you're gonna take into shallow, grassy water.  I'm not sure where you're getting the pump, but try for one that has the reverse diverter.

Your bigger problem, IMHO, is cooling.  You can't just circulate water from outside the boat. The cooling system is designed for a 50/50 mix, something pure water can't replicate.  And then there's salt water, which the motor clearly isn't designed for. And just sticking the radiator up into the air will not look good. Probably a vision interference as well.  The proper way to cool this is a closed system, which isn't light or all that simple. And then there's the exhaust.  You can just muffle it up into the air, but if you're thinking of doing a more traditional marine style, it will require injecting water into the exhaust to cool the pipes. The upside of that is you can use straight pipes, no muffler.

I don't mean to be a spoiler here.  I think it's a cool idea.  The group I hang with are boat guys, and a popular conversation is finding non-traditional engines for boats.  Our best idea is an air cooled engine with an electric fan to help cool, depending how low the motor is mounted.  And I like the GL motors.

[754]

So if  the motor is centered, and drive shaft is angled.
What is the difference between that, and a truck where it is angled down ?
 Is it not a similar setup ?
 

[jgger]

Might need a real short drive shaft would be my guess. That's why I thought the drive belt or gears would work.

[oddballmotorsports]

that kinda is the point of this, I want a shallow water boat, like the ones in NZ where ya see them running aground, jumping berms etc,  yes the driveshaft needs to be angled, but only about 1-2* so I'm told to keep the U joint needles spinning to stay lubed,  but at about 4" inches, that's a bit much, unless the shaft was long.  my thought was a closed loop cooling system,  it seems to me to be a more reliable setup anyhow, as the engine stays at operating temp. piston to wall clearances are tighter, etc etc.  I didn't think a heat exchanger was that much money for a used one off ebay..  and the gears or belt isn't a bad idea at all,  I  can assume both the engine, and the pump run clockwise, as that's pretty standard,  but I don't know.. as far as manifolds,  dunno that one either,  but (huge but here) there might be a twin cylinder marine motor that has the same exhaust port spacing,  whole lotta if's I know,  but these ideas, may never produce something,  but its fun to flex the ole brain muscle.  I think it could work, I will be building a jet boat,  its just a question of what motor to use..  I like the idea of a harley motor, I wonder if there's any divorced transmssion jap bikes that are liquid cooled?  I Think moto-guzzi's are but, yeah, not cheap power plant... nor jap lol

[Yamahawk]

GL1100-1200 engine are very common and cheap. I would look into using a CV joint behind the flange off the output shalt instead of a U-joint. They take angles way better than U-joints. As for the 1-1 drive, there is a gear in your transmission that will approximate it, and why not overdrive the pump to gain higher top speed? I wouldn't re-engineer the motor, just use it as it is! I neutral, you could upshift and gain your drive to the pump, and get good thrust. Use an electric fan on a radiator for cooling, and you should be good to go!
Charlie

[333]

That would be a huge stroke of luck to find the right exhaust manifold.  More than likely, is that you find a manifold you can modify. And then, you'll need a separate water pump for it.  Marine V8s  that don't use a closed system, don't use the automobile style water pump, but have a high output pump that feeds both manifolds, and the motor, which is made for raw water cooling.

The style of boat you're trying to emulate is a racing boat.  And as such, isn't very practical.  Even those who have just taken a jetski engine/pump assy and put it in a jon boat, don't have a practical fishing boat in the end.  What they do have, is a boat that can make one guys face hurt from a day of grinning, but you won't have a boat that you and Da Boyz can spend the day on.

You would do better to make an air boat.  The motor would already be mounted up in the wind, you wouldn't need to cool the exhaust, and it would be easier to connect to a propeller.

[754]

The newer style CV joints we used on the high clearance truck handle up to around 3o degrees shaft angle.
 Make sure you have an adequate scatter cover whatever you use.

[Bankerdanny]

Seems to me that 1:1 is somewhere between 4th and 5th gears.  Much easier to take the power from the shaft, over figuring out how to seal the crankcase after removing the transmission.  Also, keeping the clutch gives you a way to have a neutral.

That is my thought too. Put it in 3rd, which is 1:1, and then just leave it there and use the shaft coming out of the engine to connect to a V drive or similar output.

It would need to be a smallish boat though, the GL1100 isn't that powerful.

[333]

'82 & '83, 4th is 1:1.   '80 & '81, 4th is 1:1.065, 5th is 1:0.829.

[70CB750]

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