On a 4 stroke, do I really need pedals?

thxcuz

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I’m planning on building a bike in the near future. I’ve built a 2 stroke and now I’m considering a 4 stroke. One question I have besides “how do I make it less ugly” is this:
Do I need to keep the pedals? I don’t need pedals to start it since it’s a pull start. Couldn’t I just weld some foot pegs on the frame?
Sure, if it breaks down or runs out of gas I’m screwed, but I tried riding a puch maxi with pedal power only once or twice and found it’s easier to just walk it.
Just wondering
 

bonefish

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You could just weld pegs to it, but it wouldn't be a motorbicycle then. You would have a scooter. You are better off buying a used scooter. I have a Yamaha Zuma 125cc and it flies. Make note. In some states you need a motorcycle endorsement if over 49cc's.
 
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thxcuz

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In Missouri a motorized bicycle is anything under 50cc with an automatic transmission. It doesn’t need to be registered.

That being said, common 2 stroke kits are technically illegal but I’ve talked to several cops who said unless you’re being stupid you won’t have a problem.

Your municipality may be different
 
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Tom from Rubicon

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50cc with an automatic transmission = engine with centrifugal clutch in low cost builds.
49cc Huasheng engines will burn out the clutch bell often if you don't pedal up to 5mph. Don't want to pedat?
A motorcycle is in your future. Any other way costs $$$. I know cuz I did.
First build Huffy Davidson Just to establish a stable rolling speed. saved the BBR clutch.
Build #2 a Sportsman Flyer 80 with a Bully GoKart clutch probably does not need the pedal start.
Other better and wiser builders, I hope will guide you in your 4cycle build.
Tom
 

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May 22, 2020
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I can add a little bit from recent experience, you're gonna want to keep those pedals. On one of my bikes I removed the chain and have both pedals forward. I have had to do the walk of shame a couple of times and here in Houston, it is very not fun. It also depends on your size or engine size, 49cc with my 240 pounds causes the belt to slip a bit when taking off which is not the best. Same setup on a bike with pedals where I can pedal up to ~8mph then take off, no slipping. Take that for what you will.
 
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Venice Motor Bikes

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The pedals are very important because you need to pedal to take off (to keep from burning up the clutch in the first day of riding).
Also... if you decide to use a 'cruiser' style bike, the pedals work the rear brake.

& last... as the others said above, without the pedals, you're legally driving a motorcycle or scooter which falls under different laws!
 
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thxcuz

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Ok, you guys convinced me to keep the pedals. Now then, how do I make the 4 stroke kit look less like I’ve got a lawnmower strapped to my bike?
 
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Tom from Rubicon

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Ride confidently, a smile on your face will cause viewers to want to emulate you. My first build a Huffy Davidson never hit the road before a bicycle horn was mounted to salute all I pass.
I don't know where you live but Whizzers are a part of Americana, and oldsters know them. Kids see and like a engine powered bicycles. The next year after I first starting riding around our little burg a guy just up the road from me Built a
2 stroke bike, and rode in to tell me I was his inspiration.
A photo of your build will be most appreciated.
Tom
 

thxcuz

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Thanks for your help
Tom, I’m just in the planning stages at the moment. I have 3 frames to choose from.
A) a nice Peugeot mixtie frame that I’m confident I can fit a 2 stroke on
B) an amf cantilever frame
C) a slightly older amf frame

Another question is am I too heavy for a 4 stroke? I’m a fat guy but I’ve rode 50cc mopeds and scooters without much problem. I’ll be urban driving 100% of the time with some mild hills.
 
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Tom from Rubicon

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I weigh 170 out of the shower. Benchmark.
My 50cc Bikeberry /Huffy build came with a 44T rear sprocket.. But on the advise of a co-worker I used a 31T and it handles barely, the average hill here in SE Wisconsin and on the flat about 32mph. The 44T should do fine for you.
Tom
 

Tom from Rubicon

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Even the
Amf Roadmaster flying falcon
Does not have the butt joint welds of a Schwinn Typhoon. You are a big guy and need a robust frame. Either frame with store bought mounting brackets could even fit a 212cc Predator. Depends on what local constabulary let go. If you don't attract attention. and smile alot and don't exceed posted limits. At least here in SE Wisconsin we enjoy mindful of traffic full use of the roads.
Tom
 
May 22, 2020
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Another question is am I too heavy for a 4 stroke? I’m a fat guy but I’ve rode 50cc mopeds and scooters without much problem. I’ll be urban driving 100% of the time with some mild hills.
I did mention I am around 240 pounds and have 2 bikes with the 49cc one with 36tooth and one with a 40 tooth sprocket. I haven't had any issues with the 40 tooth with really fat tires. The 36tooth got up to 30.44 on my GPS before running out of space, haven't checked for top speed on the 40 tooth. Another tip if you are gonna get a 4-stroke, do NOT get one with the smaller pocket bike transmission. This POS, I have had a couple crap out on me.
20200901_144451.jpg
 
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Citi-sporter

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Do away with all the cover and make it look like a motorcycle engine, somewhat. Covers are for stationary power, don't need for moving bike............Curt
I would think if the bike sees a lot of summertime, city traffic I''d keep the shroud and forced air cooling as these engines are often times run within an inch of their maximum duty cycle, especially if climbing a long hill with a tailwind. I like the look of shrouded aircooled engines, and the whir of the fan means you know the engine is being kept cool. Besides if you take the fan and shroud off you have to come up with some sort of way to prevent clothing and other hanging bits from entangling in the rotating flywheel. And the biggest issue: how will you easily pull start the engine?
 

Citi-sporter

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I did mention I am around 240 pounds and have 2 bikes with the 49cc one with 36tooth and one with a 40 tooth sprocket. I haven't had any issues with the 40 tooth with really fat tires. The 36tooth got up to 30.44 on my GPS before running out of space, haven't checked for top speed on the 40 tooth. Another tip if you are gonna get a 4-stroke, do NOT get one with the smaller pocket bike transmission. This POS, I have had a couple crap out on me.
View attachment 105628
Or if you're a lighter rider, you could bolt up a Honda GX35 which the transmission will easily handle the reduced torque. Run a bigger rear sprocket and enjoy having a 24 mph top speed. Slow is also good.
 
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5-7HEAVEN

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I would think if the bike sees a lot of summertime, city traffic I''d keep the shroud and forced air cooling as these engines are often times run within an inch of their maximum duty cycle, especially if climbing a long hill with a tailwind. I like the look of shrouded aircooled engines, and the whir of the fan means you know the engine is being kept cool. Besides if you take the fan and shroud off you have to come up with some sort of way to prevent clothing and other hanging bits from entangling in the rotating flywheel. And the biggest issue: how will you easily pull start the engine?
Citi, totally agree.

The 212 engine on my cruiser project looks trim and very pretty with shroud off, exposing its shiny scalloped billet flywheel.

One day my shoe's gonna grind onto the fan blades.

And those blades spin up to 7,000 rpm!

My shroud stays on.

Since eliminating the pull start, I'll install a 7" circular plexiglass window to showcase the flywheel.

FYI, I'll have an electric starter PLUS a cordless drill to spin the engine.
 

Tom from Rubicon

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Curt's shroudless advise is spot on.
The engine is not running stationary. Do motorcycles have blower fans?
My 1950 Harley and my 1979 R80/7 BMW don't have fans.
When the recoil start of my 79cc took a crap. I removed it. What to do with the plastic fan? Copper
chisel got rid of it in short order without damage to the cast iron fly wheel. The manufactures must expected the recoil start to fail. When the shroud is off there is a rope start
spindle. Before recoil start anything, You engaged a knotted end of a rope wound at least 4 revs. the balance terminated with a wooden toggle. Pull start
Disregard 30wt for 15-40 or 20-50 in warm weather. Standard motorcycle lube in warm weather
Pant clips will save you from the dreaded cuff wind.



My only drivetrain interference comes from my boot on left side bumping into the Bully Clutch.


When in doubt, ask Curt, he is one of the few who have been here from the beginning.
Tom
 

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