MZ/MuZ Riders

I had a goal of getting the bike back on the road after a busy fall and winter. I went slowly through the sprag clutch spring rework that HMMNZ posted, then got it back on the road, but one day shortly after, it would not start, and after tinkering with it a bit, I don't think it's getting spark. Definitely turns over, definitely getting gas, seems to be timed right, just doesn't start. Any suggestions for troubleshooting? New plug, checked plug boot, fuses. Thanks in advance.

First thing to do (unless you have already done it) is pull your plug, ground it against the engine, then crank it over and look for spark. This video shows you how:

http://www.howcast.com/videos/176258-How-To-Check-For-Spark-in-Your-Engine

If there's no spark, check the kill switch. I had intermittent starting on mine when I first got it; turned out to be a loose wire connector on the fuse block I had to re-solder back on. Also my side stand switch gave me problems, so I bypassed that by disconnecting it's brown ground wire and insulating it under the seat. Also check the spark plug wire for continuity with a meter. Hope it's something simple like these examples and not a bad coil or CDI box. -Don

Thanks guys. I just now got a chance to fool with it, and it was just a ground issue in the kill switch. Back running on all cylinder... Now the heck of it is that I missed spring riding weather! It's already in the 90s today. Looking forward to getting back to riding.

-=jn

most of the problems i have been sorting for
fellows here local seem to be piddly electrical problems
like crud in switches pieces of copper turned green in side the plastic
most of it from poor quality wire and connectors

most of the china made toys i have worked on seem to suffer from the same thing
poor electrical the quality of the copper wire sucks

some china made stuff have soft heads they used the wrong metal
once you find the japan made head that fits the motor it runs ok
guy here has a lifan 200cc sport bike with 15,000 miles
but he takes a clue from me and does not flog it hard
dave

Yeah .... I bought a cheapie emergency generator off Ebay last year but one, that was made in China. It ran a main bearing within 10 hours, then burned its windings out 6 hours after the mains were replaced.

The damned thing had a plastic camshaft! Total crock of pu-pu.

It never ceases to amaze me how Chinese engineering can find so many unique applications for plastic.

got a harbor freight 800watt 2 smoker here
its got about 10 hours on it
i will give a report after ham radio field day in june

it will probably go 20 hours in 24 if it does not pop first
running about 40 to one stihl chainsaw oil so that may help
been using it to run my black and decker electric push mower
on a small part of yard beyond cord range seems to do ok
i just hate B&S 4cycle push mowers its a hill side and they die from over heating and poor oiling
and the lawn boy 2 smoker is apart being worked on
dave

I will be going over my Mz's (thumper's) ignition curcuits today, as on way home last night I lost sparks at the plug, all the other electrics worked A-ok. after 20 mins of fiddeleing and just before I phoned for the breakdown truck I gave her one last try and she fired up and got me home, well to the bottom of my street and died, again all the other electrics work fine. This morning after 9 hrs standing, she fired up as if nothing was wrong so i think her ignition coil is on the way out.

does anyone agree / dissagree with my conclusion?

do check the wires and spade connectors
my 660 traveller died several times one day
found one of the spade connectors loose at the coil
cleaned spade and blade and tightened the spade
and no more problems
later i soldered a new spade on the wire
i solder spades that crimp that way if one breaks off the wire
i can re solder it on the road crimping means new spade that you may not have

dave

Do check the sidestand microswitch and make sure the switch is making/breaking by the sidestand on the switch's metal contact. They get bent and if it's stuck closed a ground is applied the the CDI box and it will never start.

do not think the rotax powered bikes have the side stand switch
stand is spring loaded at least on my saxon tour
dave

The Silver Stars sure do. And it shows one on the MZ 500R factory schematic I have also.

mine is titled as a 1995 and i do not remember seeing a switch ..i will look
mine has also a metric speedometer

dave

Unless someone removed it, it's there. Brown and Blue wire on it.