No spark, please help!

Message

Tommy36 · #1 Post by **Tommy36** » Thu Jun 28, 2012 6:23 pm

Hi. I hope someone can point me in the right way. Im building a YZR 500
replica with a costin chassi and now im realy close to a first start of my newly rebuild rd 500 engine. I cant get a spark from the plugs and i have cheked everything and everything seems fine, i have signal in both the orange vires into the ign coils, but no spark. New ign coils, tested ground ok. pick up coil and ac gen OK. But the YPVS servo motor behavies strange, somtimes when i turn ign on it works and sometimes not, sometimes it lives its own life. Does the YPVS box control the ign in some way? New battery, RD500 standard wire loom, I have no tachometer installed, does that matter or should i have a spark anyway?
I would really need some help because in july 19 we have a twostroke track day in LinkÃƒÂ¶ping and i would realy want go there!!
What have i missed?

//Tommy

aaronmvrider · #2 Post by **aaronmvrider** » Thu Jun 28, 2012 7:51 pm

disconnect the ypvs servo motor with the powervalves in closed position

it should be ok to start it if you can get spark

sounds like the pv motor is issue

HWY9CA · #3 Post by **HWY9CA** » Wed Jul 04, 2012 7:53 pm

Check the cylinder head ground to the coil ground.

Maybe chassi ground need a wire run to it????

PV disconnect is a good Idea..