I Love My Two Stroke Bike

[xlite]

I already threw the fin shroud away.

You might want to be careful about what you throw away. Those shrouds are more than just cosmetic. I seized a VW air cooled once by failing to reinstall a 2" piece of tin that turned out to be vital to airflow over the fins.

Maybe these 50cc motors are designed conservatively enough that heat may not be an issue. Maybe.

 

[azbill]

Egor, keep us up on how it works with no shroud...
I like the look without it, but am to nervous to run it like that

 

[Egor]

Ill keep you posted. This engine was intended to be run on a edger or the like, so that is why it has all the shrouds. I know about the VW but remember it is covered up under all that car. I think one of the most important things for a small engine like this is also a good quality oil, if it breaks down and turns to thinner that will do in a friction engine like this. I know with the hot B&S engines we used to make one of the things we had to look out for was the rod. With no bearing it would fling all the oil off and seize to the crank and break in half. I think that is will be the delima with this engine if I ask too much of it. I was looking at one of my 60's Honda 50's, under the plastic shrouds this has at least as many fins. Keep you posted. Have fun, Dave

PS: I got it running today, runs good I need to install the chain. After I break it in I have some Prolong oil to run. Goes in Jack Roush race cars, it should work fine in this.

 

[Egor]

Ran the bike around a bit today, so far the oil I am using is working good. There is a small amount of gear noise, most when I let off. I like the way the clutch grabs, it is smooth and pulls good. It will be interesting to see what this thing will do when the engine breaks in. I took all the shrouds off and junked the air filter. I will find something that would work for the filter. I need to find something for the pedals the cranks that came with the kit are junk. I can put my hand on the engine after a bit of riding and not too hot to hold my hand. I ran it with the quiet muffler and that is no fun, I took the end off and now it sounds mean. I like the way it pops when you let off the throttle, my two strokes will never do that. LOL. Have fun, Dave

 

[BarelyAWake]

o.o

That's no 2smoker - get outta this thread you traitor!

 

[Egor]

I got two stroke gas in it. Thats all I have LOL, that makes it a 2 smoker. I hope my wife doesn't look at these posts. I wonder if she would like her bike now? Have fun, Dave

 

[the new ausped]

hi something i found out what other people have said+ more te engine WILL run hotter w/out all the shrouds/fancovers how u can fix this is take all the fan covers off even the one with the pull starter on it and make a costom thing so the pul start works if you need it and now the fun bit take a small hammer to all the cooling fins on the head,file and sand them down and ur set for a cool engine. how it works is when the covers arnt there to provide airflow to the head the cooling fins only create ristance of the flow it alsolooks kool i have doen this on 6 small engins 3 of them were 4 stroke and they all run flawlesley also it take up much less room and its very diferent

 

[xlite]

Somehow removing fins does not sound like a good way to increase cooling. Even worse than removing shrouds. This does not seem to be a good source for advice on motorized bikes.

 

[BarelyAWake]

Gotta agree w/that - fins = greater surface area to disperse heat, the larger/thinner the fin and the more of them the greater the cooling effect. The basic concept behind radiators for example...

 

[azbill]

I agree with xlite and BA
no fins = burnt valves

 

[GearNut]

The fins are there for cooling, Period. With the exception of certain 4-stroke cylinder head designs, water cooled engines have no need for fins.
Unless you plan on fabricating a water jacket, water pump, and radiator for your engine, leave the fins alone. 100 years of engine design has emperically proven this.

 

[Egor]

It has been too cold out for me. I have not had the bike out for a while. With the colder weather it would help with keeping the engine temp down. When I was last riding the bike, I was able to hold my hand on the front of the engine crankcase. I suspect the top end would be near 200, like I said I need to get out the thermal scan and see what it is. The small Honda motorcycles I have do not have any more fins than this engine. But like our bikes it is always moving, and convection with all the shrouds missing. Have fun, Dave

 

[xlite]

I suspect the shroud is not needed unless you go full power while stationary for extended period. These engines were for pump and generator which does but not likely on a bike.

 

[Egor]

Rode the bike with the engine like this. Gotta keep your fingers out of this mess, LOL. So far I have just ridden the bike I still need to use the Thermal Scan. I like the mechanical look if I decide to keep it this way I will make a guard to cover the fins. I like the look of the bike with the old B&S engine that showed up at the Eldorado Park in Long Beach Ca event last summer. Have fun, Dave

 

[Egor]

Well I put some miles on the bike with the shrouds off and then took the thermal scan to it. I left the engine running. This is what the numbers are.
Rocker Box 99*
Top of the Head next to the plug 199*
Crankcase 140*
Gearbox 105*
Engine cases under the carb 95*
Outlet to the exhaust 290*

If I put the covers back on I will get the numbers.
Merry Christmas everyone.