Schwinn Occ with 70's briggs flathead?

[Chainlube]

the engine is also at angle because I don't want to modify the frame if I can help it.

Hey, you're good already, no carb or exhaust. Make a new intake manifold and build the angle into it so your carb is level/(ish).

I have my 3hp on a mini-bike and the carb isn't exactly level until I sit on it, then the suspension sits down.

 

[DieselTech]

Hey, you're good already, no carb or exhaust. Make a new intake manifold and build the angle into it so your carb is level/(ish).

I have my 3hp on a mini-bike and the carb isn't exactly level until I sit on it, then the suspension sits down.

Well ain't that a cool little trail rig. What actually is that @Chainlube what brand or model?

 

[GW's Motorized]

I do know the history of the engine...

The engine was used to run a conveyor belt on some farm machinery, it was rebuilt then put in a shed, a friend of mine later was given the engine, and he put it away until he gave it to me.

 

[Chainlube]

Well ain't that a cool little trail rig. What actually is that @Chainlube what brand or model?

There was no name on it when I got it, so I'm not really sure who the maker would be. But I viewed a Mustie1 video and he has a Rupp which looks very similar to this one.

 

[Chainlube]

I do know the history of the engine...

The engine was used to run a conveyor belt on some farm machinery, it was rebuilt then put in a shed, a friend of mine later was given the engine, and he put it away until he gave it to me.

No worries, they're super easy to work on and not complex at all. Most of the time they have a vain type governor which is easy to remove.

I made the intake and exhaust for mine. The carb is a PZ19 with just stock jets, nothing fancy. The exhaust is kinda pieced together though and I'll be making a more one piece design soon. As she is, she's a strong runner and sounds cool. I put a 196cc on it at first but I couldn't even ride it, it would just wheelie the first touch of the throttle.

 

[GW's Motorized]

No worries, they're super easy to work on and not complex at all. Most of the time they have a vain type governor which is easy to remove.

I made the intake and exhaust for mine. The carb is a PZ19 with just stock jets, nothing fancy. The exhaust is kinda pieced together though and I'll be making a more one piece design soon. As she is, she's a strong runner and sounds cool. I put a 196cc on it at first but I couldn't even ride it, it would just wheelie the first touch of the throttle.

I was told it had a standard governor, but some of the 3hp briggs had an electric rev limiter in the points, which kept it going over a certain rpm

 

[Chainlube]

I was told it had a standard governor, but some of the 3hp briggs had an electric rev limiter in the points, which kept it going over a certain rpm

If you pull the side cover with the pull start off, you'll find out if there is one. The two flat heads I have are the same.

 

[Wrench]

The older Briggs cams are relatively soft. The valve springs are pretty weak also. They are not fully hardened like a cars cam. It was common practice among racers in the stock classes of kart racing to spec their cams if the lift was under
specs by removing the back side. Briggs at one point went to plastic cams. I have done this many times.

The only part of the cam that's been hardened is only the first .020" (if that) of the outer surface on the cam lobes. Maybe bearing races and the gear teeth. That's it the rest of the cam is soft
It's so easy to grind thru .020" No wonder why ya think the cams are soft

As for the plastic cams the lobes have a hardened metal skin and the gear is made from a special high density plastic

It was common practice among racers in the stock classes of kart racing to spec their cams if the lift was under
specs by removing the back side. Briggs at one point went to plastic cams. I have done this many times.

By grinding the cam lobe on the bottom ya still run a chance or ruining the temper of the thin .020" hardened outer surface
But then again ya might get lucky and not ruin it, That's why I said your taking a chance

Sure Racers will sacrifice a cam to win a race. Small engine cams are cheep


I've seen lifters that were not hardened properly and they mushroomed and metal fragments broke off
Sure it took over 500 miles to get to that point. If the cam lobes and lifters aren't hardened properly your just asking for trouble

 

[DieselTech]

There was no name on it when I got it, so I'm not really sure who the maker would be. But I viewed a Mustie1 video and he has a Rupp which looks very similar to this one.

Yeah after you mentioned that, I had forgot about the ole Rupp cycles, they made some pretty cool bikes. I think they may of made a 2wheel drive trail bike.

 

[GW's Motorized]

Yeah after you mentioned that, I had forgot about the ole Rupp cycles, they made some pretty cool bikes. I think they may of made a 2wheel drive trail bike.

speaking of 2 wheel drive bikes, does anybody else want a Rokon train bike