Ignition pickup coil part #

[Srinath]

Nope, screws were in, and @ 3 out. I removed em, made sure everything was clean and still no start.
Cranks over well, sparks well, has compression, but will not fire.
What could it be.
I actually ran it about a year ago, 30+ miles, and it ran phenomenally well ... till it stalled.
The carbs are the same as they were then, all clean matter of fact.

Cool.
Srinath.

[Srinath]

OK I cant get it to fire with starter fluid sprayed in the manifold without carbs on. In fact I managed to light it up outside the manifold, and quickly put it out with a rag I had lying about. OK so no damage done there.

So I am getting spark - I can see it just fine, but how is it not lighting up inside the chamber ?
Is the timing of the spark off ?
Is that controlled by the different trigger pickup coil ?
Is that an ignitor box issue ?

Cool.
Srinath.

[den]

am i understanding this right ,, the bike worked fine!! you parked it up for a long while , you havnt touched it and now it wont start,,you thought it was the ignition timing coil? but not that ? have you done anything to the engine pryor,
if you got compression then thats ok , is there an auto decompression system to ease starting ,,at fault maybe
you got spark,, thats good , but is it sparking at the right time ,, the thing with easy start is it maybe firing on leftover vapour and not necessarily at the proper timing mark??
have you got the use of a timing gun,,
always buy and use a brand new spark plug when diagnosing engine problems.

for a better understanding tell us everything thats happened so far,so many posts ,
ps ,
you on aftermarket exhaust or original,,what pressure you getting from the tailpipe when you turn it over,,

[DAVID THOMPSON]

some of these big motors have an automatic compression reduction built in the cam system ...
if they crank to slow they do not work correct
B&S 5 and 7 hp lawn mower motors come to mind
i do not know if the 660 motor used on the mz has this

if it does try bump start from top of big hill in second gear
and yes you probably live some where its so flat this is not possible
dave

[Srinath]

OK approximate sequence of events.
2011 april - I buy the bike, clean carbs etc etc and get it running. Its fairly reliable, and a lot of fun.
Ride it till say nov 2011, and it doesn't start any more ...
I trace it after many months to a disconnected ignition coil. Then It seems to progressively get harder to start.
Then april 2012 it dies on a friend mid ride. He trucks it back. Then I replace the starter clutch, and swap a transistor in the ignition box. It stays hard to start, especially when hot/warm.
Then oct 2012 I get it started and on a 30 mile ride.
It has good power but on the off ramp 3 miles form home it stalls and does not start again ... Not yet ...

I have so far after that, made sure carbs are clean.
Swapped the crank trigger coil for a new one off a 01 660 raptpr.

The old iridium plugs make spark 10 times brighter than the new regular ngk dpr8ea9 plugs - those are GS500 plugs, so now I know to get iridiums for the GS too.

So, new crank trigger, same ignitor box as before ... no start. It also didn't give any inkling of firing on the old crank trigger which I still have sitting around BTW.

Cool.
Srinath.

[Srinath]

I dont think it can be anything other than a shifted rotor tha tcauses a brilliant spark @ the wrong time. So wrong that it will not fire at all.
I will get back to it when I can after surgery (today).
Cool.
Srinath.