36MPH on a 4 Stroke

[JerryAssburger]

Does anyone else wonder this?..... I see people purposely leaving off cooling shrouds on fan-cooled engines, thinking they're doing the motor a favor. My thinking is, the engine fan at 4500-6800 rpm is throwing a heck of a lot more air past those fins than moving through the air at 20-35 mph. (Most vehicles REQUIRE their cooling fans up to 35 mph*) Also, unlike an air-cooled motorcycle engine, the fan-cooled fins are smaller for a given bore size, I'm assuming because their size is based on the assumption the fan and shrouds are in place.

Just wondering....

*Automobiles. Supposedly, once above 35mph, the radiator fan usually isn't required.

 

[Chainlube]

Some guys are looking for a more vintage look to a modern engine and shrouds look way to new and that's why they remove them. Most of those bikes are show pieces and are never ridden hard or at all. Never delete your shroud if you like your engine.

 

[Thxcuz]

Not to hijack the thread but I hear a lot of people talk about clutch issues. What size is the shaft? Could a go cart clutch work or even a cvt? My only experience with a 4 stroke is from a Subaru ex21 I put on a motorcycle frame. It got me to 50 with lots of room to spare.
I know these are only 49cc and a completely different animal but I’m wondering if some go kart/mini bike parts would help

 

[Drewski]

I have also heard the 144F can rev higher now but I guess older ones were still rpm limited. Not sure how high the 144F can rev but it has a little more power people say.

A lot more power, sofar I got it to rev to what I believe is about 9000+rpm with a nt carb

 

[Sidewinder Jerry]

A lot more power, sofar I got it to rev to what I believe is about 9000+rpm with a nt carb

Get a tachometer/hour counter, then you won't have to believe it might be 9000+ rpm; you'll know exactly what rpm it is. These techometer/hour counters are very affordable and easy to install.

 

[Karl Snarl]

I had an eho 35 it was too underpowered for these hills. With vigorous pedaling it would make it up the hill but if not pedalling you could jog next to it. 49cc is an improvement,

View attachment 104686

Most kids/people are going to run 2 strokes regardless seeing the wide pedals as some sort of issue. Also ranting about 40mph top speed. I'd rather go 10,000 miles with a slightly lower speed than 3,000 miles and a rebuild. 49cc 4 stroke kit motors are a Honda in a nutshell much like the 49cc 2 strokes being copied from a japanese motor. My engine has no problems so far just everything around the motor breaking like I said the 49cc 4 strokes are usually good engines except for bad rings and rods break every once and a while going full rpm down a hill from some of the stories I heard. Sometimes improper break in will cause them to go bad.

4k miles on a 2 stroke, still looks awesome inside. No scratches, just a little normal piston skirt wear. Rings still seal nice and it runs like a top!! Now the frame is crap. More scrap welded to it than a modern artist crap work. You could almost call my scrap yard of a bike art if you look at it like that. Its got 4k miles though an no signs of slowing down. 2 strokes last just as long as a 4 stroke if you take care of them.

 

[LewieBike]

A lot more power, sofar I got it to rev to what I believe is about 9000+rpm with a nt carb

The Honda GX25/31/35's are rated at about 9K maximum and about 1.3 to 1.5 hp. and they have forged steel with needle-bearings on their rods with two piece forged crankshafts running in ball bearings.

I kind of doubt the HuangShen Honda clone copies with their plain aluminum conrod with splash lube can take a steady diet of above 7000 rpm at load.

Honda's first US sold motorcycle; the C-100, 49 cc Super Cub has a 9K rev limit. It will actually float the valves if you run faster than 8500. There was all sorts of intake and exhaust trickery used on these old Honda bike's engines to get 4.5 H.P. out of 49 cc's that I don't see on these HS44 engines. The fact that you can only get 1.6 h.p. out of the HS versus the1962 Honda C-100's 4.5 h.p is telling me that you'ld be lucky to get 26 mph out of a HS engine. Honda's little C-100 mill would just touch 42 mph on a flat road with a skinny rider like myself aboard. Hondas ran 17x2.25 tires and weighed about 160# and had a 3 speed semiautomatic clutched transmission. They were marvels for performance per cubic inch in 1962.

 

[Karl Snarl]

The Honda GX25/31/35's are rated at about 9K maximum and about 1.3 to 1.5 hp. and they have forged steel with needle-bearings on their rods with two piece forged crankshafts running in ball bearings.

I kind of doubt the HuangShen Honda clone copies with their plain aluminum conrod with splash lube can take a steady diet of above 7000 rpm at load.

Honda's first US sold motorcycle; the C-100, 49 cc Super Cub has a 9K rev limit. It will actually float the valves if you run faster than 8500. There was all sorts of intake and exhaust trickery used on these old Honda bike's engines to get 4.5 H.P. out of 49 cc's that I don't see on these HS44 engines. The fact that you can only get 1.6 h.p. out of the HS versus the1962 Honda C-100's 4.5 h.p is telling me that you'ld be lucky to get 26 mph out of a HS engine. Honda's little C-100 mill would just touch 42 mph on a flat road with a skinny rider like myself aboard. Hondas ran 17x2.25 tires and weighed about 160# and had a 3 speed semiautomatic clutched transmission. They were marvels for performance per cubic inch in 1962.

I like learning. Good read right here, yesum.

 

[LewieBike]

https://www.cyclechaos.com/images/c/c4/Honda-C100-Ad.jpg

Note that in the Cyclechaos article they call the C-100 an OHC, when it was a pushrod OHV. Think a bit about that, because at that same time Harley's OHV Sportster was making less than 50 H.P.

 

[Karl Snarl]

https://www.cyclechaos.com/images/c/c4/Honda-C100-Ad.jpg

Note that in the Cyclechaos article they call the C-100 an OHC, when it was a pushrod OHV. Think a bit about that, because at that same time Harley's OHV Sportster was making less than 50 H.P.

I like fuel economy with my power and not to mention reliability. I like vintage Kawasaki's. Most all of them are flat tappit engines. An most are a breeze to set the valves on. I say most because they also had some that were shim under bucket. Those are a pain in the arse.