Yamaha RZ350 CDI problem FIX? Yamaha RZ350's (especially 1983 and 1984 models) have a CDI problem that causes it to fail over time. A used unit from a a newer model don't work unless you replace most electrics. I heard of some people fixing this problem by taking the CDI apart and replacing or soldering the fault. It's hard to take the CDI apart but I never seen anyone release the fix or a schematic of the CDI with test procedures. Does anyone have a schematic/circuit details or know how to test, FIX this CDI? All the info I have listed here I found posted in newsgroups, etc but does not include repair info. If you change the stator/CDI/coils from a newer model, it will work BUT it would be nice to know how or why the CDI units are failing and what (transistor/diode/resistor) needs to be resoldered/replaced. PLEASE post any technical info about this problem. I'm interested mainly in the 1983/84 CDI info. New CDI's also have problems but don't have a high failure rate like the 1983/84 models. Someone below also said they fix the problem but never posted the fix and the e-mail from 1997 don't work anymore. --------------------------------------------------------------------- This may sound obvious, but did you check the spark after it cut out. Supposedly there was a design flaw in the cdi box that caused them to fail at a high rate. My bike has a broken box. Have to preheat the box or park under the hot sun for it to start. If you have a bad cdi, it's $$$ to replace. --------------------------------------------------------------------- My second CDI box quit this summer. BUT I fixed it !!! Took a couple of hours to dig through the epoxy and gravel but I have fixed it. I am about to attempt this on another box in a couple of weeks. Do not throw away your CDI boxes just yet. Just in case I have actually figured out how to fix them and it aint just a fluke. ---------------------------------------------------------------------- i assumed that the YPVS and ignition system would be nearly identical. I could not find any spec regarding the CDI unit, in fact the manual stated that Yamaha had not released details at the date of publication? ---------------------------------------------------------------------- tighten a large hose type clamp with a dowel on top mid-point applies pressure to the circuit board in the CDI for it to work again. This is ONLY a temp fix so you can find a replacement or fix your old one. Three CDI types on Yamaha RZ350: 29K-50 for 31K 1983-1984 RZ350 52Y-50 for 57V/1JF 1985-1986 RZ350 1UA-50 for 1WT/1UA/3DH1 1987 on ?
Had an '83 250, load of fun My fix was to sell the bike before it failed..... Why do they fail? One known cause was they were prone to fail if spark plugs were not earthed whilst engine kicked over. ie. if the ignition energy cannot be dissipated via the spark plug then it dissipated in the CDI...what a great design!!! Sounds like the usual "save the 20c fuse" by burning out the $200 electrical component. I still have some brand new platinum plugs floating about. Prob suit the 350.
My bad...maybe..... we may be talking about a different black box.. I vaguely recollect there was the ONE blackbox that did all sorts of shite, inc the YPVS system and timing.
