I'm becoming a total water-head?

[Aqua Zombie]

:heresyoursign:Hi there world of hydros! I am brand new at this great sport and am starting off on the Minimax level. I am wondering if anybody knows about how far my prop should be in the water when the boat is compleat? I am building the motorboard now and my brain is turning to mush over how tall, or short the thing should be. The motor will be a greentop KG7 H. Any info would be apreciated. (this is my first post here as well, Woo Hooo!) Thanks.

[mdaspit]

:heresyoursign:Hi there world of hydros! I am brand new at this great sport and am starting off on the Minimax level. I am wondering if anybody knows about how far my prop should be in the water when the boat is compleat? I am building the motorboard now and my brain is turning to mush over how tall, or short the thing should be. The motor will be a greentop KG7 H. Any info would be apreciated. (this is my first post here as well, Woo Hooo!) Thanks.

A lot of really smart, really good guys on this thread to help you, in the meantime, go to the top of the page under the "search" function, search for "minimax". I know there have been a number of posts in the past, may be something there. lots of good information in that library. Probably good stuff about your KG7 also.

[Aqua Zombie]

I will do just that! Thank you for the direction.

[DeanFHobart]

Make the bottom of the motor cavitation plate even with the bottom of the boat.

Good Luck.

[mdaspit]

Make the bottom of the motor cavitation plate even with the bottom of the boat.

Good Luck.

There you go Zombie- and from Dean Hobart no less. You can take that to the bank.

[ebss011]

u need to buy a 102mod and a hydro! get alittle bit of wheel time and go have fun!youll never sleep good again!ok makin another one!

[Aqua Zombie]

Thank you Dean. That lines up with every thing I have heard. I wonder though... Am I over engineering it to make it an inch or so lower, leaving me the option to shim it up for more adjustability?

[jeff55v]

Make the bottom of the motor cavitation plate even with the bottom of the boat.

Good Luck.

Question: Does a KG-7H have a Quicksilver lower unit?

[DeanFHobart]

Yes, the "H" means it came with a quicksilver lower unit.

[DeanFHobart]

Thank you Dean. That lines up with every thing I have heard. I wonder though... Am I over engineering it to make it an inch or so lower, leaving me the option to shim it up for more adjustability?

That will work also. However, don't run out of 'clamp' .... the amount you can jack up the motor and still have the clamps on the motorboard.

Good Luck.

[hydroid]

Hey AZ, check out www.muskokaseaflea.ca, dedicated minimax/most fanatics, largely in Ontario, Canada.
I have a KG4H, goes like stink. Your boat will fly!

[DeanFHobart]

Remember, if you run the cavitation plate below the bottom of the boat, there is a lot of "stuff" dragging through the water.

Good Luck.

[B Walker]

Yes, your over-engineering it.

You would never run this with the cavitation plate below the bottom. Ever.

Back in the day, some people were known to run that with the center of the prop shaft level with the bottom. I dont recommend that.

So thats your high and low max dimensions.

Set it up with cav plate level with bottom to start. raise it up 1/4" at a time till the prop looses bite. Go down a quarter, your good.

Good luck with your project.

BW

[Aqua Zombie]

Thanks all again! It is starting to make a little sense up in my wheelhouse now! Though the gears do turn a bit slow up there. Ill get some pics up for you all as soon as I figure out how. And to you B Walker... that is what had my head spinning a bit, because I have heard of people running their prop halfway in the water before. I am new to all this and learning bit by bit every day. This project is just the start. I can feel it getting into my viens allready!

[Silas_53A]

all racing applications run the CENTER of the prop pretty much at or just below the bottom of the boat. Even though it may seem counter intuitive (didnt make any sense to me a couple years ago) running the prop half out of the water is faster.. by a lot. Thats why, in a lot of classes, there are restrictions to exactly how high you can run the motor. At a certain point it can become dangerous and/or cause damage to the motor, such as being hard to control and starving the motor of water causing overheating.

[Aqua Zombie]

Got ya Silas... In the case of the kg7h engine I will be running most of the time, I think I will play it safe. I know the green top was made for thrashing once opon a time, but I feel a bit responsable In owning It and preserving it. So I think bottom of the cavitation plate is going to end up level with the bottom of transom. Mabey a 30 horse something or other that I have less sentamentel value for might see the prop level with the transom for shear amusement and terror? But that remains to be seen

[Silas_53A]

in the case of your motor I wouldnt be concerned about damaging it unless you have a bad crash. over heating is an issue with Yamatos because they do not have an impeller. The water is forced through the cooling system by the prop, but if it is raised to high the prop may not be able to do this effectively. At the cavitation plate may be a little low, even for your application. I would make sure to leave room for some raising, once you get use to it you may want to squeeze some more MPH's outa her.

[Aqua Zombie]

Thanks for the websight referral Hydroid. I was wondering how you throttle your kg4h? Do you use a deadman or just the throttle and advance linkage on the motor itself?

[hydroid]

I run with deadman, and the mag is locked at full advance, lever tied off to forward gas tank mount.

[RichardKCMo]

What that guy said !!!

[Aqua Zombie]

Im stoked!! I just got my throttle linkage in the mail from Frank Erion. It is a bueaty factory clone of the original linkage. Very well made! The guy was nice enough to hand write constructions for me on how to put it on, and even allow me to call him for help If I needed it. Now that I have this motor mostly together I am ready to mock the lower unit up with the transom and finish this boat. Guess its time to learn glass and resign!

[hydroid]

AZ, could you provide a couple of pics, different angles, of the linkage assembly. I might replace the one I have if the engineering/functionality is better.
Thanks,
Erik

[Aqua Zombie]

You got it Hydroid. Ill try to get a few up on saturday for ya. I would be interested in lookin at what you run as well if you are able to post anything.

[Aqua Zombie]

Here ya go Hydroid... Let me know what ya think.

[Aqua Zombie]

Just for kicks, check this one out. Controlls the throttle and advance at the same time. I bought this one this way. Also notice the two yellow wires hangin out of the mag. That was their kill switch mod.

[hydroid]

AZ, great pics, thanks for the detail, my setup is almost identical w the cable clamp and bent arm support.
Your engine is mint! I'll PM my phone #, want to discuss your refurbishment process - my KG is torn down, block/tower ready for stripping/painting and want to compare notes. See mine attached on a 20SSH hull(a little heavy). I have lighter ASH hull on which I will run it this summer.

20507

[Mike45]

AZ,

The motor looks sweet. :congrats:I am glad to see Charlies drawings in action. The man never ceases to amaze me. If thier is anything you need to know about the old mercs I'll bet he can answer it. The only downfall is he does not use a computer.

Hydroid's Pitures are pretty cool to.:congrats: My dad is going to put a 10 Hurricaine on his old "B" this summer to mess around in the river I am curious to see how she flys.

[Aqua Zombie]

Thanks there Mike45. Ill keep Charlies in mind for my ever mounting merc guru list. And I hope your Ole Man has a blast on the river!

[Aqua Zombie]

Thats a good lookin setup hydroid! She looks mean! I bet the lighter ASH will really scoot! Go ahaid and pm me sometime and well chat.

[hydroid]

Thats a good lookin setup hydroid! She looks mean! I bet the lighter ASH will really scoot! Go ahaid and pm me sometime and well chat.

Can't find your PM info on HR. I'm at B:905-858-4917
Want to know if you sodablasted prior to spraying block/tower.

[Aqua Zombie]

No media blasting on this one Hydroid... Though you could. I have used black bueaty on alunimum before. It will alter the surface of the metal a bit though. I don't know about other media out there' as I have only used black bueaty on alunimum. Wallnut shells might be softer and may have less of a "splash" when it hits the metal. I would get yourself a scrap alunimum cased something (transmission tail housing, piece of a transfer case, alternator, anything cast/scrap/cheap-free) and hit it with your media, Then shoot some paint on it to see if you like the result. Just try to find a casting that has about the same finish as the condition of your tower. I would still strip the final pieces chemically afterwards though, as alunimum is a bit porous. The media removes paint on the surface in a hurry, but if anything is left permiated in the casting such as dirt, water, oil, rust, or even paint, it may show up later, just as the judge is about to critique it.