Cannonball Goes Totally Insane And Buys a CG!

OK L2 think I have the basics worked out for your above idea. Its fussy but not too complicated. And its an FD of course. Send me the parts and I will build it for you.

Added a few upgrades. Got the small expansion chamber exhaust, certainly not a Hi-pro piece but does run markedly better than the stock. To fit the bike I had to weld it to my modded header(longer length) which I suspect helped the low end a bit.

A thought on the slant head. Im not fond of it. It shows head temps up to 80 degrees higher than the old center fire. Since Im after a basic stock type engine the lower compression of the CF head suits my need better, its a smoother runner.
Engine is still not broken in but getting there. Been running with out the reeds and 4stroking is common in certain throttle areas, mainly high end. Dropped the needle a slot, helped slightly, still waiting on jets to arrive.
Im not porting, matching or anything. I did clean the flashing ridges. Im after the best running combo that is "out of the box" so replacement is as simple as a new engine.
The biggest single improvement I have made is the Jaguar CDI for the stock engine. This is the non-adjustable unit with out the internally adjusted switches. I know there is controversy surrounding these after market CDIs. I am very methodical on mods doing one thing at a time, then tweeking that before the next thing. I don't just do some thing and ride it a mile or so, but for days before making a conclusion. This engine has been running good on the improvements made, but now its running great! It runs cleanly, no 4stroking, it is smoother. It even sounds different more like a small bore 2stroke dirt bike. Idle is better and power is linear. This is not a high revver. I doubt it will make much over 30mph. But now it has smooth relatively fat power from bottom to top. Im stoked!
Maybe its not just the CDI but all the little things together. But they weren't doing what they are now with the CDI. Best money($60) spent so far!

More evolution. The small expansion chamber though it ran pretty well was a bit too noisy for harmonious life in the neighborhood. I had ordered a small muffler from China some time ago and had forgotten I had it until I found it moving things. Took it apart(it dismantles totally) and found a very nicely made baffle resembling(if not one) a small M/C design. Has fanned inlets and exits and was of large cross section. Modding it to fit, required an addition of a section of pipe. Was really amazed and pleased how it made the CG run. Its quiet yet powerful from the low end til it maxes out around 30. The nice thing is the power is now even more linear and tractable. You can poke along at 10/15 smoothly then nail it and it takes off to redline pretty quickly. Probably the added pipe helps the low end a bit. But still this is the best running exhaust I have had and I highly recommend it.
Was under $20 shipped( took two weeks). Cool thing is as I said earlier it totally dismantles for cleaning when it cokes up eventually. Not like the junk rattling welded together stock mufflers. Im thinking these might have been for a motorbike/moped that was pretty well engineered/developed and sold turn key. These are almost out of the CG league quality wise.

Thing is running so well that all there is to do is ride it!(and wait for it to break)

After searching I did find a domestic Chinese produced motorbike using the muffler. Wish mine had come with the long header like in the pic. Pretty nice looking bike, front suspension, lighting, etc. Wonder if they keep the good CGs for domestic use and send us the rejects. Seems like it sometimes.

I agree, bike looks pretty fun/practical.

Name your poison and I will have it chilling for you after 5. Just come on by.

Heres a link to a similar muffler if anyone is interested. http://www.ebay.com/itm/MUFFLER-EXH...9083140&pid=100033&rk=3&rkt=4&sd=291288870109

So this build has become a test mule for what ever ideas I want to throw at it. I have been working with the NT carb and had it running fairly well. I have not built a reed engine yet so am not running the reeds currently even though they seem to run a bit better than stock in the motor as is.
After reading the pros/cons of the many carbs I bought an RT with the cable and jet set for just over $30 shipped. Jaguar of the CDI fame has an excellent website about his experiences with the CG engines. He had a good article on the Delorto carb the which RT is cloned from.
My issue with the NT was the low to mid range 4stroking. I got the top end to run nicely at WOT on a .65 jet, so the top 1/4 throttle was good. The bottom 3/4 is needle. I could find no needle position totally giving satisfactory operation. I could get it to run cleaner but it was pretty lethargic on acceleration and lean running. Conclusion was the needle profile at least on this carb is not tailored for the CG very well. Jaguar bless his heart actually soldered the needle and re-profiled it thru trial and error until it ran to suit him. not enough time left in my life for that!
So on to the RT. The adapter sleeve is a well known issue. I think the common thing to do is glue it to the manifold with fuel proof sealer then use an oring to seal the carb to the sleeve. I wanted to be able to move this carb among several engines. I got an oring that fit the RT perfectly with out the adapter. My next thought was to cut the end off the adapter and let the RTs oring seat against the bare manifolds end. Wasn't totally convinced the oring wouldn't get sucked in. So Put a standard NT oring inside the adapter put the RTs oring in the carb and slid in the sleeve. Then slid the whole thing on the manifold and double sealed the carb and adapter I don't think Im the first to do this . I had installed a .65 jet befor the carb went on the engine. Took it out for a run and wow! Ran great no 4 stroking, way more top end and excellent low speed "poking around" running. I did notice I believe due to the carbs design starting is a bit different requiring chocking more often than the NT. I did find as Jaguar did that the very bottom end right off idle is a bit lean/boggy. He solved this problem by drilling a third hole at the near bottom of the fuel tube. I may do like wise.
Conclusion (in my experience) if the carb is well sealed its a good running carb, preferable to the NT(which I like too for simplicity). I know folks have had issues with them, but short of a defective carb/bad sealing/jetting or engine issues I don't know how, it just to simple. Properly set up its gotta work. Which mine does well!

I know this has been covered times before on the forum but I must reiterate the importance of checking jet sizes. Unless you are buying genuine jets from one of the carb manufactures or a known good brand, check em out! Get a jet drill set and a caliper. Neither are very expensive. I found about half the jets I recently bought to be wrongly stamped. The boggy bottom end I was experiencing was caused by the fact that the .65 jet was actually a .60! I drilled it to.65 and it was actually a bit rich on the bottom. Soldered and re-drilled to .63 and that dialed it in.

Check em out, don't trust what it says. You my wind up chasing you tail with tuning if you don't.