Better CDI units??

[dan48cc]

ok so my bike is 3 months old and i am on my third CDI Unit. i have moved it fiurther away from heat made a sheild to put it in to keep away heat and draw in cold air. i have made my own lead from a new car plug lead but yet i keep killing them. i asked the supplier and his answer was simply that they make good batches and bad batches. this for me is not good enough i use the bike as daily transport. can a CDI be retro fitted froma motor bike or an ATV or scooter or the likes. has anyone done this. i have a cdi from a yz 125 here with all the same wires etc. however will the output range. being it is from a 125cc be too strong for my 48cc engine. has anyone got any ideas i am sick of forking out 30 bucks everytime mine dies.

 

[MotorBicycleRacing]

I have sold 100's of these 2 stroke motor kits and maybe
had one bad CDI. They are very reliable.
I have replaced a few CDI's on others used engines.

Where did you buy your kit from and who is your supplier?

The grubee kits that I sell now come with a 90 day / 3 month warranty
so it would not have cost you anything and $30 is kinda steep for a CDI

I doubt if CDI's from other motor bikes or an ATV or scooter will work

Only thing I can think of is that your magneto is killing your CDI's
or
How is your kill switch hooked up? What wires did you use? maybe that is
killing them?

A long custom spark plug lead could remote the CDI but i don't think that
is the problem

Good luck, let us know if you figure out what the problem was

PS: This doesn't belong in the BICYCLE Repair & Modification section

 

[dan48cc]

i bought my engine kit from:

Electronics, Cars, Fashion, Collectibles & More | eBay

Buy & sell electronics, cars, clothes, collectibles & more on eBay, the world's online marketplace. Top brands, low prices & free shipping on many items.

ebay.com.au

The sellers name was mrbikeboy. he offered only a 30 day warranty and the first cdi went 3 days after warranty and the second did not come with a warranty and the third was just never that good. when i first got the bike run in it would do 55kmh now it struggle to reach 35kh i put the cdi off my wifes bike on mine and it went great again doing 55kmh. i wired the blue cdi to the blue engine, the black cdi to the black engine and the white wire to the yellow/red wire then the green to the earth on the bike frame. i have no other dramas with the engines at all. as a whole an awesome package. just these **** cdi units (lol) the price i am getting charged for a cdi is $25 au plus $5 au postage. there just has to be a better solution..

 

[dan48cc]

PS. sorry bout the wrong post, and the new lead i made is only 5cm longer than the original on and provides a stronger spark

 

[fetor56]

George from MBB Imports is a decsent enough person & most of his parts are Grubee;their ok.
Try not using your white wire as a kill switch,use it for lighting power only(or don't use it at all)
https://motoredbikes.com/threads/blue-wire-kill-switch-anti-theft-device.8579/

 

[fetor56]

BTW...dunno of ANYONE who has successfually swapped to a different type of CDI.
Do we have a crash-test-dummy.

 

[jlebh1]

rocksolidengines.com.au in adelaide sell performance ones there a bit more expensive but they seem to look better they also balance every engine crank and have a hp engine with porting and polished

 

[Junster]

I'm thinking you may have a wiring problem. I'd check the mag first for any stray wires in the winding sticking thru the cover wrap. Make sure the black wire is solidly grounded to the mag frame and that when the motor spins the mag frame can never contact the spining magnet. I'd also try removing all the plug in connectors and soldering the connections. My kill switch is to white and the other side is directly to black not the frame. To kill 3 cdi units it almost has to be getting a power surge. Good Luck.

 

[spad4me]

i bought my engine kit from ebay.com.au the sellers name was mrbikeboy. he offered only a 30 day warranty and the first cdi went 3 days after warranty and the second did not come with a warranty and the third was just never that good. when i first got the bike run in it would do 55kmh now it struggle to reach 35kh i put the cdi off my wifes bike on mine and it went great again doing 55kmh. i wired the blue cdi to the blue engine, the black cdi to the black engine and the white wire to the yellow/red wire then the green to the earth on the bike frame. i have no other dramas with the engines at all. as a whole an awesome package. just these **** cdi units (lol) the price i am getting charged for a cdi is $25 au plus $5 au postage. there just has to be a better solution..

DO NOT USE THE WHITE WIRE AT ALL CAP IT OFF.
Use a killswitch that opens the blue wire circuit.
Solder and tape everything.
Seal the spot where the wires exit the magneto chamber with Goop or silicone.
I have worn out one steel frame in about 24 months time.
Never had a problem with a cdi or magneto .
Now the chain is another matter.

 

[duivendyk]

The CD unit is one element in the Ignition system,the other is the generator coil which supplies the pulse power to it.This is unusual in most systems there is only one composite unit.This makes it next to impossible to find a more reliable replacement.
Normally ignition coils are hermetically sealed,moisture penetration can cause high voltage transformers to fail over time.This CD unit is probably not adequately protected against this.It should be mounted so all the leads and come in frombehind and from underneath.Silicon rubber should be used to provide the best seal possible.it's probably a good idea to put it in a low heat oven at low heat 125 degree F for a few hours first to drive out any moisture.Also never ever crank the engine without a sparkplug connected and with the shell grounded.I think the output pulse transformer is the most likely to fail component.So don't overstress it.Another possible culprit is the energy storage capacitor .If your generator coil had a higher than normal output it could over stress the cap,or it could be marginal to begin with.Insulation breakdown is a gradual process first some current leakage then catastrophic breakdown.Whatever has been done that could affect the generator coil performance,leakage at the killswitch esp if the blue wire is involved instead of the white wire,may affect a marginal system.Which is then mistakenly attributed to the CD unit.Sometimes the spacing between the flywheel magnet and the generator coil is too wide.This reduces the output to the CD unit.A thin calling card should just fit,if too wide,reposition the coil &bolt it down securely. Good luck.