78mph

[alex_in_az]

I've been really enjoying the performance of the Panterra with the 200 engine and other mods I've done to it. The latest incarnation with 30mm Mikuni, UNI filter and free flow exhaust had me up to 72mph with the 15/36 sprocket at 7400rpm in top.
I felt the bike had more but aerodynamics were holding me back. So I bought a viper fairing and a 7" headlight to go with it. I finally got it all together on Saturday and took it out for blast Sunday when everyone else was watching the superbowl. I had 78mph showing on the gps at 8100rpm in top.
I think this might be all she has to give.

regards, Alex

[Weldangrind]

Wow! That's impressive, but I think there's always more.

Which jets are you using in the Mikuni?
Does the muffler create much back-pressure? Perhaps there's some power hiding in there.
Are you interested in "adding lightening?" If you have steel rims, they could be replaced with aluminum, holes could be drilled in gussets, etc. Are the bars aluminum?
Are you running light oil? Maybe 10W40 synthetic would free up power.
Interested in a performance CDI? That could improve spark advance.
Any thoughts on mild porting and polishing?

[Weldangrind]

BTW, your bike looks really good.

After reaching the limits of this combo, you can always increase the displacement to 223. Easy and cheap.

[alex_in_az]

Wow! That's impressive, but I think there's always more.

Which jets are you using in the Mikuni?
Does the muffler create much back-pressure? Perhaps there's some power hiding in there.
Are you interested in "adding lightening?" If you have steel rims, they could be replaced with aluminum, holes could be drilled in gussets, etc. Are the bars aluminum?
Are you running light oil? Maybe 10W40 synthetic would free up power.
Interested in a performance CDI? That could improve spark advance.
Any thoughts on mild porting and polishing?

110 main in the mikuni, bars are Al, using synthetic oil and did a port job on the intake and exhausts. I took about 15# off the frame when I did the original conversion, stripping off un-needed brackets etc.
The CDI might yield something, I think the exhaust might be worth a little bit too. I really need to find a skinny little 5'-2" girl to ride it versus my 190# fat ass.

[alex_in_az]

BTW, your bike looks really good.

After reaching the limits of this combo, you can always increase the displacement to 223. Easy and cheap.

thanks, which jug is needed for 223?

[Adjuster]

Very nice looking project.


/

[Weldangrind]

I really need to find a skinny little 5'-2" girl to ride it versus my 190# fat ass.

You're slim from my perspective. :lol:

[Weldangrind]

thanks, which jug is needed for 223?

It depends on your existing bore and stroke, but this kit will take you from 67mm bore to 72.5mm: http://item.taobao.com/item.htm?spm=a230r.1.14.77.SS7Hul&id=13243492906

BTW, that's $45.52 USD.

[Weldangrind]

Can you tell us the numbers that are stamped on the motor? They're near the shifter.

They aren't necessarily accurate, but it's a start. I have a China motor with inaccurate info stamped on it, so it happens.

[alex_in_az]

can you tell us the numbers that are stamped on the motor? They're near the shifter.

They aren't necessarily accurate, but it's a start. I have a china motor with inaccurate info stamped on it, so it happens.

163fml

[Weldangrind]

If your label is correct, the engine has a 63mm bore and a long stroke. To install a 67mm or 72.5mm bore, you'd need to either enlarge the case mouth or swap cases. A new set of cases is cheap at TB.

That would take you to about 229cc with the 65mm bore and 268cc with the 72.5mm bore. Sounds like fun!

I bet that would push you to 90mph. :D

[alex_in_az]

If your label is correct, the engine has a 63mm bore and a long stroke. To install a 67mm or 72.5mm bore, you'd need to either enlarge the case mouth or swap cases. A new set of cases is cheap at TB.

That would take you to about 229cc with the 65mm bore and 268cc with the 72.5mm bore. Sounds like fun!

I bet that would push you to 90mph. :D

the head stud spacing is different between the 157/163 series engines and the larger bores. I've got a "250" jug and piston and the bolt holes spacing fore/aft are good, but side to side they are about 3/16" larger and the jug won't assemble to the cases.
I don't know how many parts could be re-used in a set of wider cases, and how many are different.

[SpudRider]

That's a neat project. :) You did a great job. :tup:

[Weldangrind]

the head stud spacing is different between the 157/163 series engines and the larger bores. I've got a "250" jug and piston and the bolt holes spacing fore/aft are good, but side to side they are about 3/16" larger and the jug won't assemble to the cases.
I don't know how many parts could be re-used in a set of wider cases, and how many are different.

I believe them to be the same FOA (frame of architecture). In fact, they share a great deal with the XR185/XR200 transmission, with the exception of electric start.

If you could find the larger case that suits the 250 jug, I bet you could swap the internals over. if you could use your existing crank and rod with the 72.5mm piston, you'll be pushing the outer limits for an air-cooled machine.

[Weldangrind]

Another thought: there is a motor that is labeled as CG300, although Humanbeing says it is actually 270. It is a water pumper which is designed for use in three wheeled trucks.

I bet the crank and piston from that setup could be made to work in an air cooled CG, with a little mixing and matching.

I'm currently trying to mate a long stroke crank with a big bore in a CB200, but the con rod length is an issue. If I can swap in a shorter con rod, I think I can make it work. The result will be 248cc. The motor I'm working with is more complex, because the CB200 uses an OHC. That throws the cam chain length out of whack as I raise the cylinder.

The CG would be much easier...

[alex_in_az]

I believe them to be the same FOA (frame of architecture). In fact, they share a great deal with the XR185/XR200 transmission, with the exception of electric start.

If you could find the larger case that suits the 250 jug, I bet you could swap the internals over. if you could use your existing crank and rod with the 72.5mm piston, you'll be pushing the outer limits for an air-cooled machine.

I have the existing CG125 engine that came with the bike. I looked at swapping in the stroker crank and 250 jug to that over the summer. this is when I discovered the mis-match in cylinder head studs. at the time I didn't want to go thru the engineering required to make it all work. so I bought a new 200 engine and dropped it in. I have a lot of the parts I need to do the swap, my only concern would be running almost double the torque thru the 125 gear train.
the stud issue could be solved by helicoils using the existing tapped holes diameter as tangent for the larger helicoil diameter, this could allow me to increase the stud width by 5mm, which might be enough. the cranks use different diameter bearings, which would require opening up the bores for them.
these all seam to be material safe changes unless there's an oil way in there somewhere.

[Weldangrind]

When you find the cost of new cases on TB, you'll rethink machining the 163. New gears from TB are also a good idea.

[alex_in_az]

When you find the cost of new cases on TB, you'll rethink machining the 163. New gears from TB are also a good idea.

That would be the easiest thing to do, My only problem with that would be making sure I got the correct parts

[Weldangrind]

I've done some searching, and the CG250 cases usually have specs with them. That would allow you to confirm bearing sizes and so forth.

The only difference I've found in the transmission is the countershaft length, but that's easy to overcome. Countershafts are available separately, and they're cheap.

It would be nice to find a complete CG250 air cooled donor engine, perhaps from a dirt bike or quad. You could do some exploratory surgery and determine stud spacing, bearing diameter, etc. You could then determine what crosses over. Try CL.

[Weldangrind]

Any updates on your awesome bike?