No Spark

[Andy B]

Hi Guys,

Hoping to get a few more thoughts on my lack of a spark...

Long story short - I finally got my 400 running like a dream! would start up lovely, idle sweet and rev beautifully... But when taking it for a run, the transmission was horrible! hard to select gears, shifter not returning etc. I suspect it had been dropped in a previous life as the gear shifter was bent, and probably the cause of the issue, and ontop of that, 6th gear had a loud whining noise....

so... i bought a second hand engine, fitted it, fresh oil, hooked everything up, and it wont run - I'm not getting a spark.


Since the replacement engine is the only unknown quantity, i checked the signal generator, and had intermittent resistance readings from it.. excellent i thought! that's my problem. so i swapped it out with the one from the good engine. 99Ω constant through the wires. still no spark...

checked the coils and leads just to be sure, and getting constant readings there too..

only thing i havent checked is the magneto/generator.. but unsure if this will have an affect? does this affect the spark side  of the elecky circuit?

and if so, how easy is it to take off? my service manual doesnt make it look the easiest of things with all the "special tools2 and what not...?

Any help would be greatly appreciated! im starting to feel like the only way to go is to pull out my hair....

Cheers,
Andy

[Chris H]

Genny will not cause a problem with the spark, people remove them on race bikes.
You need to be looking at your engine fitment, something is not connected correctly or you've damaged something on fitment.
The electrics should be as before so i'd go over any connections, are the oil light and neutral light coming on?

[Andy B]

Cheers for the reply chris,

Checked over all connections 3 times over now. all are correct and well. oil, temp, and neutral lights all present on dash as they should be. all lights work as they should and she turns over well..


had a bit more of a mess around the other night, and i got a spark... but it was short lived.. literally pressed the start button for a couple of seconds- nothing... pressed it again a second later and a spark! tried again.. no spark..

A bad earth was suggested on another forum, so ive had the loom down to the individual wires, and the earth feeds look in excellent condition.

the only other thing i can think of is the CDI's messed up.. possibly just coincidence that it went when swapping the engine?

is there any way of testing the CDI with a multimeter?

Andy

[Chris H]

Think there are some tests in the manual.
You can download from here i think, if not try 400greybike site.