dt inconsistant spark...

[twinrock]

hey guys my dt175 1978 stopped dead a while back it was running fine started to misfire a bit then died..i got it out the other day to have a look... carb is good compression good... spark not so good...if i hold the plug against the head some times it sparks some times it doesnt...i have checked the fly wheel key and all earths all good and as they should be, i replaced plug and recut lead and new cap... i always asumed that the coil is either on or off type of thing..? which leaves the cdi? i dont have a spare one to try, is there a test i can do with it..and i know u can buy a cdi kit from jaycar..? anyone had any success with them? thanks or any other clues , anyone got a cdi i can borrow im in newcastle

[pancho]

try a new plug first thing even if the one in it is a new ngk. yamaha spark is not real good and they require a good plug. sometimes a new ngk is not cheers wally.

[twinrock]

i just spoke to a guy who has had alot to do with it175 and he suggested that the crank bearings have worn out with enough play to cause an inconsistant spark as it spins the flywheel..sounds plausable especially that it does seem to spark only at certain revolutions of the crank via kick starter..

[bazza]

Guy bought my Maico,moans at meeting wont start. What have you done new plug.tried another new plug and nothing so i gave him shitty old plug from bottom of tool box and it started first kick moral of story not all plugs are  created equal

[matcho mick]

grab hold of the flywheel,give it a heave up n down,if the mains are that shot it's poling out the source coil,you will feel it bigtime if it has,your'e either deaf,or got rubber footpegs