TROUBLESHOOTING

Checking the generator on an M1 6 volt system

by: Yiqi Shao

I hope the following information can help you with your problem. There are two wire on the generator, the WA is the v out let, w is supposed to connect to the earth. Here is a way to test to see if your generator works or not.

Remove the generator from the bike. Find a 6v battery and connect the positive (+) terminal of the battery to the body of the generator (with the metal) and the negative (-) terminal to the WA of the generator. If the generator spins, it means it is good. If not, it means it is broken.

Another way is to install the generator back to its normal position. Then start it, go find an electric wire. Connect the wire with the negative (-) of the battery, the other end with the w terminal of the generator, if the light goes off, it means there is something wrong with the generator earth connection function.

M1 ignition timing

By: Bart Sanders

I would not worry too much about the idling value of 12 degs BTDC. That's still within the official R71 spec!

The result will be, that idling revs/min. are higher at a certain idle carb. setting. If you lower the carburettor
idle setting a bit, the idle revs/min. may be set to a usual 800-1000 revs/min.

Mucho more importanto is the full advance value of around 30 degs. Thaťs where your engine is delivering power and thaťs where the advanced ignition matters for getting optimal power out of a gas drop and at optimal temperature values.

Tip: you know that max. advance is reached when the lever on the handlebar is fully released. By using the excenter inside the ignition, you can set/stop it at 30 degrees. I have deliberately set the full released value at ca. 35 degrees, so that you can optimise the advance setpoint when driving. Depending on gas octane value, air humidity (it does rain in Holland!) you can determine the optimal output power easily: keep the throttle fixed, move the advance
lever a bit back and forward around the "full advance position" and you will notice that speed goes up a bit. Thaťs your ideal point of operation. Try doing that with an automatic advance system.... With only 22 hp, this does count.

Background info: I have two camshaft gearwheels, each having a TDC mark. Between these two, the gearteeth are shifted by half a tooth compared to the key positions!!! And that is indeed around 6 degrees difference.

No spark

By: Gerald Gardebled

First check if all your plug wires are ok. If they conduct power at both ends. Then make a check of the low tension wire. See if it conducts power on both end and if it is tight enough on both connections, coil and distributor.

No spark

By: George Baker

If you are connecting your meter, ground to point wire, when those points open there should be NO CONTINUITY or NO SOUND depending on your meter setting. It sounds as if your points are not opening, or somehow shorted to ground. Disconnect the condenser and try again, it could be shorted. Check where the point wire and condenser wire hook to the
points, those wires are usually insulated from the point post with little fiber washers/insulators, they may have cracked from over tightening.

My bike is an M1M which has a somewhat different ignition so I am not entirerly sure what your setup looks like.

Steering head tapered bearings

By: Wolfgang

Some company use the number SSW055, 99% are build in Ningbo. Half have printed "Made In Japan", other half "Printed in Switzerland". The bearings are standard for old BMW till 1969. Dim: Out dia: 51, inner dia:34, high: 12.5 to 12.7mm.

M1 high-compression pistons

By: Gerald Gardebled
The improve pistons are what they call high compression pistons. These pistons just have a less surface on the skirt than the standard CJ pistons and use 3 rings instead of 4. The M1-2 pistons even have less skirt surface than the DTE
improve pistons they also use 3 rings. The type of rings that are use on the M1-2 pistons are same as CJ standard OHV rings and they do a better sealing and increase the compression a bit.

The so called high compression pistons that are sold for OHV do not make that much difference and the workmanship on these pistons does not impress at all. The OHV pistons that make a real difference are the CJ original production
ones with extra holes in the skirt under the 3rd ring. These make the difference.

The problems with these pistons is that they are not an original production for the bike. If you can get the M1-2 short skirt high compression pistons that where made for the CJ production in the early 80's you can see the difference. They are much better made, I think Clay that have seen both can tell us about it too.

This is another example of getting the original product and a product made out of the CJ production. The genuine pistons works fine and are made pretty well when other ones that are not made by the right factory or at the same
standard that should be use for the CJ production are bad.

Engine Rebuild Questions

By: Gerald Gardebled

Here are some tips for your rebuild:
"- areas that are trouble spots for M1 6V engines...for example, I know that people say the piston rings that come on the standard pistons seem to cause excessive cylinder wear...do most people recommend switching to better pistons, like those sold by Dong Tian, or are the standard ones fine?" The Standard one work fine but using short skirt 3 rings pistons like the M1-2 pistons would improve performance and reduce the heat.

"- special tools that I'll need for the job ": Drop me a mail and I'll tell you in details what would be needed.

"- where I might be able to find specifics on wear that indicates the need for replacement of a particular part" : My policy when it comes to rebuild an engine is change everything but the case (if it is in good shape). If you take
that engine apart and do everything at once you won't have to come back on it before a while and you'll know that everything in that engine is new.

"- things that people recommend that I do, regardless of whether its to correct a common problem" : Use German or Japanese made bearings, try to get original parts, the best would be NOS PLA issue parts (although some claim that there is no differences, there is differences, I could spend a whole day showing these differences)

"- What is the standard cylinder diameter? What size indicates that the cylinder has been bored to the 1st oversize? 2nd?" : Standard cylinder diameter is 78.00~78.03 mm. The size after first bore should be 78.25, after second bore it should be 78.50 mm.

"- Do any of you recommend any particular reading material, whether specific to CJ engines or about engine building in-general?" : Contact me if you'd like, I'd be glad to help you.

M1 engines and why

By: Gerald Gardebled

Chang Jiang sidevalves engines, specially the M1 engine are strong and reliable ones. Their simplicity make them very easy to maintain. And if you get a M1 engine, 6 volt you will have very few issues with it. You already will avoid any
electrical issues. I personnaly run a M1 6 volt engine for more than 15 months with over 45000 kilometers and never had problem with electrical and the engine itself. I do the normal maintenance (sometime not :-) because a little busy) and everything is working well. I do highway riding a lot and never had to worry about speed and overheating. Well adjusted, with proper tools (filler gauges and flow meters) that engine will perform pretty well.) My bike is my main transportation and I was never left on the side of the road by it.

Charging light not working

By: John Frazer

A couple quick checks:

• regulator test: disconnect the 2 wires from the Voltage regulator(VR). Jumper them together. They should be blue and black/white. Start the engine, run above idle speed and the charge light should go out. This test bypasses the VR and applies full voltage to the rotor for max charging. Don't prolong this test or ride like this. If the light stays on or glows half way, there is another problem. If this test turns off the light, the VR is bad.
• Diode board test: requires an ohm meter. Disconnect the 7 wires to the diode board. Note where they go before you mess up. Using the continuity tester (on beep mode) connect one probe to the terminal where the red wire from the starter relay was attached. The other probe should be connected to each of the 3 terminals where the white wires (that come from the alternator) were attached. Note if they beep or not.
  • Next, reverse the 2 probes and repeat the test again on the same terminals tested before noting if they beep or not. Compare the results. There should have been readings in only one set of tests - ohm or continuity (beep) in both tests or neither test is bad.
• Exciter diode test: do the same type test as above checking between the doide board terminal where the black/white wire from the VR was (not the black/white wire to the ignition lamp) and the 3 terminals where the white wires were. Note the results for continuity (beep). Then reverse the ohm meter leads again and re-run the test. Compare the results. There should have been reading in only one set of tests - ohm or continuity (beep) in both tests or neither test is bad.
• Ignition lamp test: remove the blue wire from the alternator stator. Turn on the ignition switch and ground the blue wire. If the lamp comes on strong with the blue wire grounded and ignition on then the lamp circuit is OK. Do not run the engine.
• Rotor quick check (the copper winding on the crankshaft end): if the ignition light passes the above test, you can check the rotor quickly by turning on the ignition and contacting both rotor slip rings with a coin or screwdriver. The ignition light should burn brightly. Do not run the engine during this test.
• Rotor winding ohm reading: 6.5 ohms for a good rotor. There should be no continuity between either slip ring and the rotor body (ground).

That's about it for testing. Check your wires between components. The whole thing is really stone axe simple. Use this info at your own risk.

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