David Crawford: Rexspeed
mrmaxstorey: could be
2LateIWon: I have a xr250 dirtbike with weak spark not running what do you think?
Amir Shariffudin: CDI is electronic controller,collect charge from black coil inside engine, store in capacitor than discharge at certain time. small engine like chainsaw did't need sensor to syncronize it timing but motor bike have floating high resistant coil only connect to CDI both end, to do sync.
high voltage coil ,will charge capacitor in CDI, one end will connect to body of engine and another will be send to CDI.
lamp and battery coil, or power coil have low resistant ,almost zero.
DON'T USE HAMMER
mrmaxstorey: Could be. You might also have old coils/wires that fail when they get hot
Rawsome Wayne: Hi Max.i have a 1982 Suzuki GSX 400f ,it starts up fine runs well ,but as soon as it gets hot it just cuts out,i have been told its probably the CDI unit,,what do you think ???
ninjawy kawa: thnx, i will.
mrmaxstorey: It has to be a ZX11 there is way more to it than timing sequence, the CDI also controls spark advance etc. Find one on ebay and get it shipped to you
ninjawy kawa: kawasaki zx11 1992 timing is 220.127.116.11
mrmaxstorey: If you can find one. Pretty much all bikes use their own CDI's. What bike are you working on?
ninjawy kawa: thnx for ur reply , the problem is that i can't find a replacement in my country ,can i use another bike cdi that has the same ignition timing ?
mrmaxstorey: Nope, you absolutely need it for spark
ninjawy kawa: hi max,i just bought a kawasaki zx11 c3 that had been sitting in the garage for 6 years ,the cdi is fried ,my question is ,can i get it to start for a few mins with the cdi not working ?
mrmaxstorey: Then yeah go for it. Solder another wire onto it and youre good to go
mrmaxstorey: Inside the box, or external wires?
spy111kill: Hey max! I have question. Is there any way to fix my CDI boxes connector wires? Why I'm asking this is I have an ATV and the CDI boxes connector wires are off. Is there any way to fix them?
jose cardinal: its better 2stroke are smoke..and are 4stroke are not better to smoke..
whiskey bob: I run better on my smoke too!LOL
2bad4u: ok i will put it together in the morning and let you know thanks
mrmaxstorey: Theres your problem, gotta have the whole intake together and properly assembled. Without it, you will run lean which can cause the backfiring
pim1234: Great joke about the smoke ! Gonna use that !
2bad4u: inside the head, I have not installed the air cleaner as yet, with the carbs back firing think it pointless, also why would the timing be off? the bike has only 23k on it, I just bought it, sitting for a few years gas tank was completely rusted out
mrmaxstorey: Id search for vacuum leaks first, make sure the air filter is clean and installed properly. Where is the ping coming from?
2bad4u: all stock , there is also a ping in the front cyl then rpm drops comes back up for a while then ping, the carbs back fires when throttle is increased, also in intake carb holders are line up properly
mrmaxstorey: If you have a strong spark then the CDI is probably fine. Do you have any modifications to the intake or is it stock?
2bad4u: Max I have a 01 VT750 did a carbs rebuild with new parts also set flow level to manual spec, here is the problem it idles great but will not rev out, coils are good new plugs show good burn, checked timing it is out, the CDI has to be the problem,please let me know what you think thanks
mrmaxstorey: Not likely, the most common causes are problems in your carburetors or vacuum leaks
Derek Dubroc: i have a honda magna vf750, the bike will start but once running the RPMs will fluctuate up and down. normal operating range should be around 1000rpm the bike will rev up to 2000 then back down to 500 on its own and runs really rough could the CDI box have something to do with this?
mrmaxstorey: Could be, or your coil/points may be going bad
MokiEYEZ: My 79 suzuki gs750l's middle two cylinders intermittently fire, usually after it's warm. Does this sound more like a loose ground?
mrmaxstorey: Yes if you have a weak spark it could cause these problems
r1sabotage: Hello, I'm having some trouble with my cbr f3. The bike will not go over 55mph. It's like it's starving for gas past third gear. The carbs is good the fuel pump is good new plugs. It feels like the carb bowls are out of gas and when you give it gas feels like its empty. My question is can electrical produce the same symptom I'm having? I was thinking it was a fuel problem but note I'm thinking it could b spark
Chantelle Hough: crap... i think my coil is dead, i can't find a reading.......Checking again.................Yup.. no doubts...it dead. Funeral will be held.... Bring a new coil as a gift. :D
rhydiandobbin: i envy your working motorbike.
Dr. Khan MD: Loved the video, certainly helped a lot. I'm trying to track down my no spark issue on a 1986 SRX600, I was looking for a video with someone that had a similar old coil that showed how to test it, your's helped a ton.
mrmaxstorey: Very well could be. Try switching the coils and see if the spark changes sides, if it does you know thats the culprit
mrmaxstorey: They should be on different circuits. Maybe your cdi is on the way out, and the rebuilt one is faulty?
onlyadrenaline: i have a motorcycle that uses 2 plugs per cylinder. it seems only 1 plug is firing, other one, not at all. my coil resistance is 14kohm, book says 18-20kohm is acceptable. do you think the coils is causing poor spark?
Francis Collier: Thanks ill give it a try.
Brad Langille: Thinking my old enduro has weak spark. Replaced the CDI with a rebuilt one and have no spark at all. Put the old one back in, there's spark. Bike is running crappy but it will start. Got good compression. Seems that I have a bad headlight, though. Do you know if that can cause spark issues? I replaced a bad signal wire but no change in performance.
mrmaxstorey: Yeah without the cdi, you wont get a spark
ilymelissa15: i have a 110cc go kart and it want get no spark and a guy cut the cdi box out of it
mrmaxstorey: Look into vapor lock in the fuel lines, cracks in the coils, vacuum leaks around the carb boots, or float levels being too low
Francis Collier: I just bought a 97 gsxr 750... Its been sitting for 2 years. Ive changed the plugs, oil, fuel, cleaned fuel tank and lines, new battery, and cleaned the heck outta the carburetors. The bike will run at idle but when I ride about a mile down the road the bike just shuts off and then about 15 to 20 mins later ill be able to start it again. Some one please help?? Thanks
elboca123: Would anyone be kind enough to send me a (Wiring Diagram for g2 Yamaha )..Or let me know where to get one on the cheap..Thanks
mrmaxstorey: Lots of things could be causing this, vacuum leaks, vapor lock, failing coil, spark wires corroded or partially dislodged
Johnny Wieler: Ok i got a 2007 suzuki ltr wen its cold it starts good and runs for a lil...wen its warmed up it don't wanna start jus turn over??
bigglyguy: Yep, carb was the problem. With a new carb on there there's no problem at all, apart from a speed wobble developing when you redline in 6th - I've never been able to redline in 6th before :) Cheers
Living Social: I got a groupon from Miami and almost got tricked. The description was way off for that the deal they were offering. I found groupon reviews that several people had the same issue. Luckily Groupon honor a refund, but my time was wasted.