K&B outboard conversion to inboard mono engine

[casey day]

Hello i want to convert my K&B .21 air-cooled outboard engine into an inboard .21 so that i can race in a mono. I don't know if it would work to do that with that engine. if anyone is selling a .21 give me a holler. So whats your opinion about converting that motor>

Thanks B)

 

[Kez]

It will work very well. You will need an inboard flywheel and a water cooled head. Mount the engine with the flywheel facing front and the PTO facing the stuffing tube. You will also need a 0.150 cable with a squared end to connect to the PTO. Some may think 0.150 cable is too thin but it is adaquate for a K&B 21.

You may need to move the tank forward a little so that it would clear the flywheel. The good thing about this set up is that the pipe will be pointing to the transom.

 

[casey day]

thanks for the input the shaft that it has right now has a square end. im just kinda confused about how to make it work? :blink:

 

[RodneyPierce]

I thought you said Jerry Dunlap was going to help you at the next race? If your confused about it, let him show you. Its very simple...

 

[LarryConrad]

Put a K&B inboard crank, back plate, and flywheel on it.

 

[Kez]

Putting an inboard crank will work (if MECOA has it in stock) but it is not as cost effective. The bigger question I always wonder is if a P/L has been broken in with the CW crank, will reversing the rotation degrade the performance due to the different wear pattern.

 

[RodneyPierce]

Kez, it would be the same wear pattern. The piston is still moving up and down the exact same as it was.

 

[Kez]

Rodney,

With an OB crank that turns CW, during the up stroke, the piston is preloaded to the right side of the liner. Running an inboard crank would preload the piston to the left side. I am not sure if the wear pattern is significant enough to matter. I am not saying it does matter. Just saying I don't know as I have not reversed the rotation of an engine before.

Another thing to consider is the front housing. I have an old K&B 21 front housing (forgot the vintage) with a spiral grove on the inside designed to draw fuel back into the crank case. Running an inboard crank with a housing like this will blow fuel/oil out the front bearing.

kez

 

[LarryConrad]

It's just a K&B, It probably came new from the factory with more slop than a nova has after running ten gallons of fuel.

 

[Buddy Benedict]

Casey, I have most of the parts you would need to convert your outboard to an inboard see pict. The only parts I don't have is a Head Button and a Collet. If you want, I'll trade you for the outboard parts you won't need, (Gold Flywheel,Air cooled head, PTO,Crankshaft and Intake) You will need to keep your carb,case,P/S and rod.

G&M models 630-279-2451 should have the head button and collet. I would suggest you get a Keeley Turbo Head Button for your motor. It will out perform the stock K&B head Button

Let me Know,

Buddy

 

[Phil Fowler]

Casey,

Why not get a square drive cable and put it into the existing PTO(where the outboard normally drives from). Change the flywheel to one that can use a belt to start, Leave the head out in the breeze and put a water spray shield over the carb to prevent water entering.

Phil

 

[casey day]

yeah. i am just gonna show it to jerry dunlap at my next race. thanks for the input though.

B)