[grizzly11]

both were running last summer (2010) then one just stoped after someone fliped it over. The next day after fresh gas the other one quit. My aunt gave them to me and said if you can fix them great if not no big deal but they are yours now. I got one to spark randomly so tomarrow i am going to get new plugs, what else would cause the lost of spark. From what i hear this is a common problem?

 

[grizzly11]

TTT i would like to get these running for this weekend i bought a new cdi box to try. Is there anything to the plug caps besides that stiff wire that goes through the plug wire?

 

[grizzly11]

afternoon bump no one has had these kinds of problems pwc's arent my specialty so dont know to much about them

 

[rambopants]

did you ever figured out your no spark issue? I have a 89 jammer 500 with no spark but it cranks just fine.

 

[viper000]

You can modify these easily and cheaply folks, as an ex electronics guy i have found the fix, the problem with most 500, 650 and some others is that the CDI box has a rev limiter, you can order a CDI through jaycar electronics $50 AUD, or you can order a high performance CDI off ebay.

The CDI off jaycar works like a dream, beware though the main diode coming off the charge coil may blow so replace with a 40volt 3 amp schotsky diode parallel with the 5804 diode.

Be warned though, this thing now flies but you need to limit the revs otherwise your head will blow.

 

[viper000]

here's one i bought off Ebay and it works 100%

High Performance Racing CDI For motorcycle GY6-Style engine Scooter DirtBike ATV | eBay

Make sure you limit the rev's ( more than the original), otherwise pistons will start flying out.

 

[StephenJeanson]

dude it might not even be the cdi. those are expensive. try examining your electrical box and changing plugs before you deal with the cdi. im not an expert so dont take my word for it

 

[viper000]

dude it might not even be the cdi. those are expensive. try examining your electrical box and changing plugs before you deal with the cdi. im not an expert so dont take my word for it

Sorry Stephen, it was the CDI box, i did electronics and am quite competent, what is true is that the spark plug leads do eventually stuff up, but because they are moulded into the coil you can't easily change them.

Here's a 100% solution tested out by me, i used a holden VR-VY coil, then bought 2 new leads, the thing runs beautifuly, now i can change the leads without having to buy the whole lot from yamaha.