Hi, I'm planning a huge adventure, please help!

[Big Red]

Jaguar: Using the right sized sprockets, I could keep engine revs down to a minimum, correct? I don't mind pedaling, so I could have a huge sprocket for just low rev cruising on flat ground, a tiny sprocket for hills, and the inbetweens!


Or no?

Shift kit. About $150.00, is the way to go. Saw one for sale cheaper than that on this site somewhere. And low rev cruising would be a smaller sprocket.
Big Red.

 

[Deleted member 12676]

Way too much trouble, changing sprockets. Best to have your engine set up for a broad powerband and gear it up a bit for decent top speed.
Remember that these are small engines and with all two strokes the most power is had at top rpms. I would buy a 66/80cc engine and optimize the porting for a broad powerband. Also reduce engine vibration by adding or subtracting weight from the piston pin. For free, if you can give me all the exact measurements using a digital caliper, I would tell you how to change the ports using a Black&Decker rotary tool.
Check out my web site to get an idea of these kind of changes. Unfortunately I have no experience on the 66cc, only the 48 and 55. But I have the formulas for exact calculations for porting that applies to any size engine.
Also, save your back and make sure the handlebars are not low. Look at my bike on my site and see how I used an adjustable gooseneck to bring them up. I hate how the 10-speed posture became the fad for non-10speed bikes as well.

 

[crowley1027]

Out of sheer curiosity, why is it better to have an expanded chamber exhaust as opposed to a very short / no exhaust? Wouldn't it produce more power if the exhaust gasses escaped straight out of the head?

 

[crowley1027]

Big Red: I know/knew about the shift kit, I just didn't know if I could change my existing sprockets to enhance the efficiency of the power range.

Jees, if someone has a HT engine laying around they'd like to throw me, I'll pay to have it shipped -- That'd be a mighty nice gesture

Haha, I think I have to wait at least 4 months before I decide to do this trip. Need to sell my car, most of all...I just don't want to wait! Haha

 

[Deleted member 12676]

Theorizing is one thing but real live testing is it. Here's test results posted on my site. On my site is also info on the best mods to your present exhaust and how to make your own expansion chamber.

On my 48cc engine that I slightly ported for a bit more top speed I compared the two exhausts on a steep short uphill (#1), a medium grade long uphill (#2), and on a long flat street. Below are the comparison results. My test engine uses the Jaguar CDI, standard head, 110psi cylinder compression, standard intake manifold, Dellorto 12mm carb, and is ported for exhaust/transfers/intake durations of 140/110/123 degrees. All tests are with the CDI optimized for best results.
______________Uphill #1___Uphill #2___flat street
standard pipe___10.0mph___19.0mph____28.5mph
torque pipe_____18.0mph___24.5mph____28.5mph

 

[5-7HEAVEN]

Crowley,
5-7 won't steer you wrong. He's been playing with various motor/drivetrain combinations for years.
I have a few bikes, and the most reliable motors I've got are a Mitsubishi TLE 43, and a Lifan (Honda clone). Both have several thousand miles on them. I haven't even ridden my HT w/shift kit in over a year.
If you want a taste of what crossing the country on a bike can be like, read threads started by Uncle_punk13 , and by Bamabikeguy. They've both done some serious traveling.
For spare parts, I'd recomend a fuel filter, and extra sparkplug.
Van

Hey thanks Van.

I'm waiting for an ultra-dependable Happy Time engine to be made available.

Or a V-twin!

 

[Deleted member 12676]

Just replace the things I mentioned and you will have an ultra dependable engine.
The Chinese will continue to be cheap. Don't wait on them.

 

[MotorBicycleRacing]

"George A. Wyman rode, pushed, pulled, carried, and crawled his 1902 "California " brand motor bicycle from San Francisco to New York City"

The only member who has ridden coast to coast that I know of.

 

[crowley1027]

Can I ask what makes a HT engine cheap? I've heard about the casting, casting marks, and poor quality, but specifically WHAT about it makes it inferior? and could ( like jaguar suggests ) it just be souped up with better parts to make it more reliable?

 

[MotorBicycleRacing]

Can I ask what makes a HT engine cheap? I've heard about the casting, casting marks, and poor quality, but specifically WHAT about it makes it inferior? and could ( like jaguar suggests ) it just be souped up with better parts to make it more reliable?

They are cheap, get one and play with it and you will get an education.

The only engines I would even consider to ride across the country
would be 4 strokes.
50 cc GXH Honda.
35 cc GX Honda
35 cc Robin Subaru
50cc Huasheng Honda clone.

I would use a quality gearbox by Staton or an EZ Motorbike Q matic.
Maybe a Grubee 4G.

The money you would save on 2 stroke oil and gas would
pay for a HT engine and that isn't even considering all the
repairs you wouldn't have to do.

If you cut corners on your engine and bike you will pay for it later
and the trip will never be finished.
The guy who posted here trying to go coast to coast with a Chinese
2 stroke never made it.

High quality puncture proof tires like Schwalbe Marathons would
keep you rolling. There was a family that biked across the country
and they were continually replacing wheels and other bicycle parts.