Possible Bad CDI By skafreak (Read 27,221 times)

[skafreak]

I have been having problems starting my scooter sometimes recently and was hoping to get a second opinion before dropping the money to replace my CDI and coil since I would want to upgrade if I am already replacing it.

The scooter is a cheap Shenke 150 (nearly identical to a Jonway from what I have gathered) that I got for free. Some days it will start, and some days it won't. When it doesn't start, neither the electrical or kick start will get it going. When it does start, it will sometimes cut out while I am riding it. The drop in power is immediate, not sputtering, which leads me to believe it is the electrical system.

When the scooter does die, it usually will not start again immediately, and tends to be more likely to start the longer I let it sit without trying.

I started by checking the fuel line, just to be sure it was getting gas, and it was. Next, I replaced the spark plug from the stock plug to a NGK plug just to make sure that wasn't the problem. I have also checked the voltages out of the stator, and it seems to be functioning properly. I also tried disconnecting the killswitch from the CDI to ensure that was not causing my problem.

I was just curious if a bad CDI is likely to cause these intermittent issues, or if it probably points to another problem, and if so, what.

Thanks in advance.

[Alleyoop]

Could also be a bad Coil Cap. Take the Boot Cap off the plug and look inside to see if the brass cup is intact they tend to break and not make good connection on the plug. Also grab the wire and try Screwing the cap on some more onto the wire. They screw on so if it just a bad Boot Cap you can just buy those and not the entire coil. Also check the wires that connect to the COIL they sometimes have a loose fit and or may touch each other tighten them onto the connectors.
Alleyoop

[skafreak]

Brass cap is still solid, boot was screwed on basically as tight as it could be, and connections to the coil were both attached solidly and did not appear to be shorting. Most likely the CDI then? If so, I am just going to replace both the CDI and coil.

If that is the case, am I likely to notice any real performance or reliability differences between the two different AC kits on www.scrappydogscooters.com/ ?

[sprocket]

There have been problems reported using those orange boots.. they vibrate on the shrouds and wear down the spark-plug treads until they are intermittent...

Buy good parts ...like NCY...their CDIs are far superior, there is a slight spark advance and the capacitors are extremely fast and robust and last a very long time.. as do their ignition coils. Oh ya, there is no rev limitation...minimal performance gains just reliability...

www.monstergy6.com/product_CDI.htm (near the bottom- if you need an AC type)

I don't sell them, I don't own shares ... I just use them...

[skafreak]

If the gains are mostly reliability of NCY parts, and if I'm not focused on dropping pretty substantial amount of money to pull every mph out of this scooter that I can, wouldn't it make just as much sense to save about $40 and get the non-racing model from here www.scooterworks.com/NCY-CDI-Unit-VentoGY6-P5931C461.aspx and also grab a NCY coil at the same time?

[Cruiser]

Welcome to Scooter Doc, skafreak. Sounds like a good diagnosis. Also sounds like you do your homework on parts researching and getting the most for your money. Let us know how things work out and don't be a stranger if your problem is cured. It would be nice to learn more about you in the new members section along with maybe some scoot pics.

[Alleyoop]

Skafreak,
Good decision buying both Coil and CDI.
Alleyoop

[Bong]

I have Scrappys Orange Coil and CDI on my 50cc. The Plug boot is a little loose but, I have had no problems in the last year or so. Very decent product for the money. You can get a new boot from any auto parts store.

Have you adjusted the valves lately? That could have something to do with the hard starts. Just a thought before spending money on a Coil/CDI package

[skafreak]

I decided to just take the dive and have the standard NCY CDI and coil ordered already. I plan on slowly replacing pretty much all of the cheap parts and eventually pretty much just having the stock engine and frame over time anyway, so no big deal tossing in a bit more money right now. I even am kinda hoping to replace all the body panels and basically create a steampunk scooter, but time will determine if I ever get that far.

I haven't tried adjusting the valves yet, but I will definitely be doing that when I have the time to tear the whole bike apart and rebuild it, or alternately if just this replacement doesn't solve the problem.

My grandpa bought it and rode it for about a year and a half before tossing it my way, and I seriously doubt he performed a PDI when he bought it, so I plan on doing that myself this summer. Just need to get it running reliably enough that I don't get stranded around town all the time before then.

Thanks for the input everyone.

[sprocket]

I always check with the NCY website. Sometimes things are called NCY brand but in fact they aren't...

www.ncy-motor.com.tw/english/products_2.asp?ano=00000&bno=8&sno=0&abpop=&pay_year=0&pay_month=0&pay_day=0&Page=5

Are you certain you need an AC powered CDI? They also come in DC powered...

[sprocket]

How you tell the difference between an AC and DC CDI

Attachments:

[skafreak]

Well, unless scooterworks is in the business of buying off brand and labeling it as NCY, I guess I just have to take their word for it. From website appearance alone, I would be more likely to trust them than most of the other scooter parts stores I came across. Their other NCY listed parts are labeled as such physically, and the image they have for the NCY CDI is the same basic black CDI shown on the NCY website. With the way the oriental market it, it wouldn't surprise me if there were a lot of NCY branded parts floating around that weren't actually NCY production (probably even in the hands of reputable businesses that don't even realize it), so I guess really you just have to hope for the best.

And yes, I know that I need an AC. I did the research long before coming here, and surprisingly actually know how to look through the manuals sections on here to be sure. Mostly I just needed advice on what to look for in buying one, and whether a bad CDI is likely to cause intermittent problems, or if that would have been indicative of failure elsewhere (both of which I seem to have gotten good answers for).

[sprocket]

Sure that is an NCY CDI, I didn't mean to say it wasn't. Just good to check the manufacturer's website.

I suspect your problem is the pick-up coil...if it is a 2008 or older...

When it dies have you checked for spark?

[skafreak]

Makes sense, just came off sounding that way a bit.

It is a 2008, and the times that it has not been starting, I have not been able to get spark. In hindsight, I haven't thought to bother when everything was functioning to see how bright the spark was. Probably should have mentioned that previously, heh.

[sprocket]

Last summer there was a large run of bad pick-up coils on 2007-2008 GY6 scooter. You might consider replacing it, they are $12.95

www.scrappydogscooters.com/125_150_4-STROKE_PARTS.html

Otherwise you have to buy the whole stator to get the pick-up coil...