Anybody know anything about the magneto magnet

[LandSpeedRecord]

The simple way to think about the magnet is the notch for the woodruff key should be at 1 o'clock not 11 o'clock if you hold it with the notch at the top. We got a weak batch of magnets one time and it was **** to figure out so I learned these pretty well. Everyone has told you the right way to go so far. You are almost certainly facing jetting issues. These motors change drastically over the first few hundred miles so set your goal to make it ridable for now. You can not get the jetting spot on because it will change that much as the rings seated in. Follow all the tips here for soldering jets and tuning. One other tip I will throw in if it will fit your manifold. Pick up a new NT carburetor and try it with the needle full lean or one click from full lean. This may be a simple way to make it run pretty well across the rev range thru break in. If you are new to these the NT catches a lot of flack but in reality is simple, easy to tune, diagnose, cheap, and having it to slap on there will give you a baseline and diagnostic tool for chasing problems. Good luck, keep is posted and most important, HAPPY MOTORING!

 

[Schrockie]

I've been having problem getting my china girl to start. I measured ohms on the CDI and inside the magneto case, blue to black 380 ohms, black to white 13 ohms, from the installation book I have those are above normal. I tried 2 different carbs both are giving off fuel and I tried 4 different spark plugs.Does the carb have to be perfectly level? This motor isn't even trying to start. I've pulled the gun out and am ready to use it.

Scobby225fre: Have you found the post by Crassius on magnetos and CDI

Can the jug in the pic of this different motor be fix? Both motors are 66/80cc.

Please Help
Troy

 

[Schrockie]

Scobby225fre: Went to Crassius's profile and look under statistics, there you'll find all his threads he has started. Found both his cdi and mag threads, found them but didn't understand them!!

Troy

 

[Agreen]

It could be welded if you can find someone to do it. It will probably cost more in welding than just getting a new jug.

Have you actually tested for spark? There are only 3 things an engine needs to run. Fuel/air mix, spark, and compression. If you get those, you should have some coughs at least. Testing the CDI is not as simple as doing a resistance check. There's a whole bunch of stuff inside that can't be checked, and if it's not ALL working then you won't get spark.

Use an actual spark tester. Get one from a parts store and pedal it until you either see spark, or you run out of breath trying to see spark. Clutch engaged, of course.

If your multimeter does AC voltage, then try disconnecting the magneto wires (blue and black) and put the 2 leads on the multimeter leads. Tape them on if necessary. Either ride the bike or spin the wheel on a stand with the spark plug out. If you're getting voltage, then the magnet and stator (sometimes referred to as the "speaker wire loop") are good.

If you aren't getting spark and you are getting a voltage on the magneto, chances are you have a bad CDI. You could also have the kill switch hooked up wrong, or it's shorting out the signal (which can also be checked by the multimeter). If the resistance of the kill switch is short (under, say, 100 ohms) without the button pressed, that's the issue. It should read a very high (several KOhms or
O.L.) then short <1ohm when pressed. Remember, black to black to black, blue to blue to blue, and don't let the white wire touch anything. Tape it up or heat shrink it and put it aside.

 

[crassius]

the thread I referred to is 'checking your timing':
"http://motorbicycling.com/showthread.php?t=56351"

that stripped intake hole is hard to see, but may be fixable with a helicoil or a large brass bolt to redrill to proper size (tapping to a larger size may not leave room to mount the intake)

I see no mention of whether spark plug gets wet in presence of spark - that usually tells a lot about what's going on.

 

[Schrockie]

Checked my magneto and it's throwing out almost 30v, had spark and fuel, still nothing. The engine with the cracked intake is brand new, so I swapped out CDI's and bingo, it started. Now the problem is that chugs, bucks and kicks, and as soon as I disengage the clutch it dies. Took apart carb to make sure everything was unobstructed, all good there. Messed with idle screw and noticed a little change. Any suggestions?

I now need another CDI and a gas tank, any help on that?

Thanks
Troy

 

[Agreen]

Sweet. Now that it runs, you can probably rule out the magnet

I need to make a video of an NT carb explanation. The idle screw only adjusts idle speed. The needle accounts for less than 3/4 throttle. The main jet is for wide open throttle issues. There is no idle mixture setting on the NT carb. Some of these must be idled up pretty far to hold a decent idle. Sometimes there is a leak between the intake and carb, which can be remedied by using an oring.

 

[MEASURE TWICE]

Hey great the engine is turning over and now just adjustments are necessary to get it perfect.

A Coleman Chinese gas generator set I had to replace the magneto that has the CDI molded into it as an integral part. This meant I could not measure but with OHM meter and Spark. It was so intermittent I just bought another as the Chinese part was a lot less expensive than the Briggs Engine parts.

 

[crassius]

if during that chugging, it is smoking a lot, then trying to start it without spark may have filled your motor with fuel - keep it running for a while and it will straighten out

 

[Schrockie]

Slapped on the stock carb from new engine and running 100% better. Taking it for a 5 mile jaunt to what its like when up to temp.

Troy

 

[Schrockie]

Now that everyone has help to get my bike running, I still have a question about timing. It's a one cylinder engine with a woodruff key on the magneto. You don't have a second cylinder to test against. I'm not knocking anybody, I just know with a 4 cylinder I can turn the distributor until it fires right. One cylinder timing? I looked at Cassius's thread on this and couldn't understand what or how he was doing this.

About changing out the carbs: why didn't the first one work,I think I bought the next higher upgrade from bikeberry, then went to a stock and almost just fine. Needle position? If someone could provide a credible/useful link on this subject so I can figure why it wasn't working would be helpful.

On this rebuilt motor, take off is slow, lit bit sluggish until 10mph, head temp 290+/-f

I appreciate everyone's help, and thanks go out to you

Troy

 

[maniac57]

Now that everyone has help to get my bike running, I still have a question about timing. It's a one cylinder engine with a woodruff key on the magneto. You don't have a second cylinder to test against. I'm not knocking anybody, I just know with a 4 cylinder I can turn the distributor until it fires right. One cylinder timing? I looked at Cassius's thread on this and couldn't understand what or how he was doing this.

About changing out the carbs: why didn't the first one work,I think I bought the next higher upgrade from bikeberry, then went to a stock and almost just fine. Needle position? If someone could provide a credible/useful link on this subject so I can figure why it wasn't working would be helpful.

On this rebuilt motor, take off is slow, lit bit sluggish until 10mph, head temp 290+/-f

I appreciate everyone's help, and thanks go out to you

Troy

The only easy way to change timing on a chinadoll is by modification of the CDI for adjustable timing.
Any mechanical change would involve custom machining or offset keys or some such. Not enough gains to be worth the effort.
Do it with electronics.

 

[Schrockie]

I am: minus a CDI and a gas tank for my 2nd bike. Can anyone point me in right direction?

Thanks,
Troy

 

[crassius]

my timing thread was to check timing for no-start problems - one would use a timing light to check it

standard carb is usually best for standard motors - any "performance" carb is always a lot of work

 

[maniac57]

http://motorbicycling.com/archive/index.php/t-28439.html