A Briggs and Stratton question

[Jesse]

Hey guys, I have a nice non Jeep related question for you to ponder over the winter.

Now that my Jeep is pretty well done, I'm thinking about what to do next summer. I've always wanted to build my own motorcycle, maybe something like the early 1910s type of thing. Those early bikes had a cool belt drive type setup that would be pretty easy to replicate. In any case, something more like an early motorcycle and less like a mini bike.

So here is my question. If I took a standard run of the mill 5 hp briggs and stratton and took off all of the sheet metal on it, would it still run at an acceptable temp in a free air type of way? Once I did that I was also going to trim down the flywheel to get rid of the "fan blades" on there. I'm not looking to gain performance as much as make the engine more "motorcycle-y" looking. I realize that it probably wouldn't be able to sit and idle with this setup for very long, but that is fine.

Let me know what you think!
-Jesse

[p3ferris]

It will run fine with the sheet metal off of it but the govenor will have a hard time adjusting.  The fins on the cylinder are what keep it cool.  To help this situation put Slick 50 or equivilant in it with the oil.  The fins on the flywheel are what run the govenor. When the engine slows down the air off of the gov. travel to the flag that runs the idle speed so this will be an issue.  When taking the fins off of the flywheel you must  also consider reballancing the flywheel or you will go through crank bearings left and right.  The fins also help keep it cool so slick 50 reduces the friction thus the heat.  Mini bikes and go carts were my favorite things to build.  Your chain saw engines are faster but a long run the 4 cyl. are more durable.

[Jesse]

Oh yeah, I guess I forgot about the balance of the flywheel as well, but that could be taken care of. I thought of removing the fins after reading an old Popular Mechanics article about tuning two stroke snowmobile engines, they suggested it to help the engine wind up faster. This isn't really my aim, I'm looking more to clean up the look of the engine by removing the recoil, sheetmetal, ect.

Could the govenor be disabled so that it isn't a factor with the flywheel? I thought maybe I could replace the stock carb with something more like a mikuni of the correct size, since I have good experience with them on other motorcycles. That would also eliminate a govenor.

Thanks for the advice, I had been previously cruising google for answers, but I pretty much only found things like " DOOD what If i taked my LaWn MowEr and Made It really FaAst    how Much wooD that coSt??!!> THanks " On there. I knew someone on the jeep board would know what to do for a good old briggs, and could actually help!
 
-Jesse

[p3ferris]

Yes the gov can be disabled  just take the spring or linkage that goes to it off.  The purpose of the gov is if you get a sudden load the air from  the fins stop blowing a great amount when the engine starts to get a load on it then it makes the genine speed up by getting more gas in the carb.  Also  when you let off of the throttle the gov. job is to slow the engine down easy. An abrubt shut down will kill the engine.  This can be remideed by remembering to down throttle gradually.  By experimenting you will learn more, like excelerating.

[Carls_jeep]

You don't really need the manual governor for a mini bike but you can use an electronic governor to limit the rpm.

[p3ferris]

I do not know how the people will comment to you here but it is a site you can try
http://neighborhoods.ebay.com/tractors-lawn
 They may have the advanced knowledge �to help. �Electronics is not my friend and they have many things out there that can control engines.  

Looks like carl has the same idea at the same time

[Jesse]

Thanks guys!

-Jesse