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]

Originally Posted by 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?

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]

Originally Posted by 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.

thanks, which jug is needed for 223?

[Adjuster]

Very nice looking project.


/

[Weldangrind]

Originally Posted by alex_in_az

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.

[Weldangrind]

Originally Posted by alex_in_az

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=...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]

Originally Posted by 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.

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.

[alex_in_az]

Originally Posted by 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.

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.

[Weldangrind]

Originally Posted by alex_in_az

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...