MZ/MuZ Riders

OK Some of you may know my 13 month fight with my skorp.
OK if not - here it is as a recap.

I bought it april 2011. It needed work, which I did and it ran ... and I rode it several 100 - maybe about a 1000 miles till spring 2012. It was getting hard to start around this time.
Spring 2012, my friend borrows it, and it dies on him, about 20 mins after he fills gas. He trucks it back to my house.

So in summer 2012, I work on it, do several things to it, swap the starter clutch and other stuff and it is still hard to start, but it would usually start, it tended to die soon after starting ...

Anyway 2012 october, while still hard to start, I get it started and ride it 20-25 miles and as I take the highway exit, it dies. Till then it has made plenty of power on that ride and run like a charm ...

I have not managed to get it to start after that. It has spark, it has gas, I think its got compression (something I will check soon)

Worse yet, I bought a second skorp - a 96 in september 2013. I got that bike running with a few hours of work. It starts easier than this one did when it was running well.
The non starter has the carbs, battery, ignition box etc from the running 96.

What could be happening.
Oh yes once in a while the thing will misfire from the exhaust.

Thanks.
Srinath.

Oh the piston is @ TDC with the timing mark pointing up on the rotor.
The thing cranks nice and good, fast enough, as fast as the 96 does ... they have the same battery, so they crank similar.
The air filter from the 96 is on the non starter as well, and both bikes have the same supertrapp exhaust, so the non starter has the carbs, air filet and pipe = to the running one.

There is a new ignition trigger pickup coil in the non starter, but it didn't start before taht with the old one either.


Thanks.
Srinath.

clamp a spark plug to the head with a clamp put plug wire on it
in a dark room crank it and see if there is spark at the plug
if there is you have a fuel delivery problem
dave

DAVID THOMPSON wrote:clamp a spark plug to the head with a clamp put plug wire on it
in a dark room crank it and see if there is spark at the plug
if there is you have a fuel delivery problem
dave

With the Iridium plug in it, its bright enough to read a book.
First thing I checked.

I bought a parts bike, and ran it after 2 hours of work. I have 1 last theory.
The rotor may have moved a bit on the crank ... I cant eyeball and use a plastic straw to tell if the TDC is where the rotor mark is if its only a few degrees.

So I will have to yank that and look at it.
I also have a compression tester coming ... next thing to check ...

In fact, I am thinking of swapping that whole cover with the 96 ...

No fuel delivery problem ... the carb that was on the running 96 is on the non running 00.

Cool.
Srinath.

As long as you have Fuel / Compression-Check PSI / Spark-(What's that plug look like ??) Check with plug on the head ?( Fat & Blue is BEST !)
( try removing the air cleaner, Spray Carbs with Quick start fluid or even better WD/40 (Don't over do it !) through the Carbs.
If it's back firing through the Carbs, or burping back through the carbs. Maybe your Clearance is off ?
Say, Have you Checked Your Valve Clearance's ????? ( In. , in. 0.004 to 0.006--MM. 0.15 to 0.20,,,,Ex. , 0.006 to 0.008--MM. 0.15 to 0.20 )
Leak Down test would be next.
Ig. Timing check.

Have you drained the tank and replaced with clean fuel?
See my post on What's in my tank??
Also it could be the coil breaking down.

Have you sprayed either in it yet? That will tell you for sure if it is a fuel problem.

I did the ether - and I am never ever ever ever doing it again. I set the manifold on fire ... no fire in the chamber even so. I was able to put it out without damage though.
The gas is fresh, and its also what the 96 runs on, and the gas is right now in my GS as well and I am riding it currently. Its fresh new gas I have been moving from bike to bike as I remove tanks etc etc.
Valve clearances are fine - set them on both the 96 and the 00.

@ Olddog: What coil is breaking down ? The ignition coil or the trigger coil ?

Cool.
Srinath,

You might want to check all the coils in your Ig. system.
They all could fail due to heat or vibration. ( Along with all Connectors, Grounds,Kill switch, Key Switch)
Now then,
Who has the test Values ?
What's the Spark Plug look like When the engine Dies ?
What's it look like when it won't Start ?
Same ?
You may have to use a New plug to see the Dif. !

I have bright spark. I can read a book in darkness when its sparking ...

It may be off a few degrees ... that or compression.

Cool.
Srinath.

You may check your timing marks ?
Rotor Key ?
It's going to be something simple ! Right ?

Yes rotor woodruff key and key way, and if the key way is wallowed out there is the pproblem ... waiting for some time and daylight after work ...

Cool.
Srinath.

spray wd40 in the chamber and put the plug back in , if the ignition timings off a little it will still fire,,
your coil lead to spark plug my go faulty when its in position but correct itself when testing the plug/spark outside the engine(the bend my correct a breakage)

do you have the use of a "colour tune kit"
do you have the use of timing strobe light
have you used a compression tester
your certain your valves are closed at tdc

you have checked the obvious
side stand switch
neutral switch
handlebar on/off switch
ignition switch

dont be cross ,, it sounds like your sure you have tested everything and everything is fine,,but its not starting so you have misunderstood something,,breaking it down, fuel/compression/spark,bang= power,then theres the failsafe devices to consider,

Good point on the contact in the wire/plug setup, yes a odd bend to check the spark can make good contact where in the fitted position it wont - thanks I'll check it out - may be even spray wd40 in the chamber - yikes ...

Colortune kit - No, but the bike ran very well with the carbs it had, even though it was hard to start ... it actually wanted to stall right after starting ...
Timing light - No, may buy it from Horrible freight soon. But I can check the rotor to see if the keyway has wallowed out and "walked".
Compression tester - coming soon.
Valves are closing @ TDC, I checked that several times ...

All switches are fine, I see spark and it ran fine last year and the switches may have deteriorated in the year since, but I still get spark ... The spark is nice and blue and bright ... I doubt the interlocks are bad.

Cool.
Srinath.

I've been watching this thread for awhile now and I HAVE seen a plug test good out of the cylinder,and not fire with compression! Stupid question...has the plug been changed for a known good one?