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Mastiff wont start in the morning!

PostPosted: Sun Jul 24, 2011 5:51 pm
by Bodskis
Hi, my Mastiff 660 wont start if its left more than 10 hours or so and requires a jump from my car. The battery out put is strong and I have a new iridium plug. once started it works perfectly every day.

My friend recently fixed a Raptor with the same symptoms and it turned out to be a faulty pickup/sensor on the flywheel (or was it generator?). He noticed that the plug sparked against the cylinder head whenever he reconnected the CDI unit and it would appear that the sensor did not detect this spark, hence the CDI cut the spark and refused ignition. He fixed it by running a wire fom the sensor to the battery whith a push button to deliver the initial charge then the Raptor started first time, every time. Has anybody else had this prolem? I also hear it is quite a common problem on Yamaha XTs.

I turn the fuel tap off every night and also wondered if I have a fuelling problem or am I causing flooding with too much choke, is that possible? With the car attached, it will fire up eventually but I feel this is just because of the sheer voltage causing the sensor to respond if it is faulty.

It all sounds a bit beyond my mechanical ability and I hope someone has an inexpensive solution as I think the bike is superb and I refuse to trade it for a "mainstream" bike. This is my 3rd MZ and so different to my Supa5 but I am now an ardent MZ fan but this problem is getting me down! :?:

Re: Mastiff wont start in the morning!

PostPosted: Sun Jul 24, 2011 6:28 pm
by DAVID THOMPSON
i never turn off the fuel tap at night
and never use the choke unless its below 40 deg f
skorp traveller

my rt125 gets upset if you move the throttle open any when first cranking it

dave

Re: Mastiff wont start in the morning!

PostPosted: Tue Jul 26, 2011 4:56 pm
by Bodskis
Thanks Dave but I just found the answer to the problem.

It sure enough is the blue wire from the sensor! It exits the casing near where the top run of the chain exits from the front sprocket and had worn bare, exposing the metal from the wire which was was touching the casing. I can only assume the pickup was discharging that important signal charge into the casing, well thats my amateur theory anyhow!

Damn that starter motor must be tough! I absolutely hammered it for 10 mins until I found the cause and its still sweet and starts immediately albeit with the right amount of MZ quirky starting proceedure.

Thanks again Dave, your 125 is as temperamental as my 660 but I suppose its part of the charm of owning a make of bike as quirky as an MZ. :D

Re: Mastiff wont start in the morning!

PostPosted: Wed Jul 27, 2011 10:24 am
by DAVID THOMPSON
your problem seems to be the standard problem on these bikes
something electrical but different next time
i will look at that wire on mine

my 660 traveller is the Q bike
too many mods by past owners
and so few miles the engine was not broke in
starting to run OK now

the rt125 is nice once you learn it's do not's
like do not open throttle when trying to start
19000 miles since july 2002 9 years 2111 miles per year
but 4 other bikes to ride here so it sits a bit
dave

Re: Mastiff wont start in the morning!

PostPosted: Wed Jul 27, 2011 9:57 pm
by MSW
Glad you got it sorted Bodskis, but just in case someone else has similar problems and reads this, I'll echo what Dave said. These bikes (and by that I mean Baggies and Mastiffs - I've never owned another MZ) do seem to have a thing with hard to chase down electrical problems.

The part that repeatedly has been the culprit in my case is the crappy switch gear where the starter button and kill switch are located. I've traced more than one starting problem there on my bike and found that what I feared was a catastrophic electrical failure was just a corroded contact on a cheaply made switch. Each time, my problem was solved by disassembling, cleaning, and reassembling it. Now, that area is the primary suspect whenever something goes wrong electrically on my bike.

Re: Mastiff wont start in the morning!

PostPosted: Thu Jul 28, 2011 6:13 pm
by Bodskis
Cheers for that, like you say these posts can be read by other Baggy owners and hopefully steer them in the right direction. Owning these bikes tends to be more of an adventure, I guess thats why we own MZs not Hondas!

The front brake has been a problem for MOT in that I just could not bleed the brakes up enough to stop the lever touching the bars so I borrowed the master cylinder from a GSXR1100 and it soon cured it. That said, it was only borrowed and I'm now searching for the lever and master cylinder from an ETZ251 which is possibly the finest front brake on any motorcycle I've ridden in 250000 miles of courier work. It has amazing feel and its true to my intention to keep my Mastiff/Baghira cross as MZ as I can.

My first MZ was a TS250 Supa5 about 20 years ago, my Silverwing had died from massive courier abuse after 140000 miles and I needed something quick to get back to work. The MZ was strange at first and to be honest bloody awful, but being stuck with it and its foibles I grew to like it. The first time I got me knee down was in the rain on a rush hour roundabout to rapturous applause from journalists covering the launch of the latest ZZR1100 at Knot Mill Kawasaki.

You learned a whole new aproach to engineering in those bikes which is echoed in the Baghira and Mastiff and our lack of dealer backup is causing me to find new and erm, "interesting" ways to solve problems, needless to say I'm glad to be back in the fold!

Re: Mastiff wont start in the morning!

PostPosted: Thu Jul 28, 2011 10:03 pm
by DAVID THOMPSON
master cylinder

an early 80,s BMW r65 or r80 may have one that fits
and would be easier to find levers for
in fact BMW is a good source for mz repair parts

i raided my BMW used parts bin for a clutch lever and perch
and a cable adjuster from a perch and adapted a extra clutch cable
from my Saxon Tour to work on the 660 traveller
has adjusters on both ends but it works
used BMW switch gear from the pre 1974 models can be cleaned and used
to replace the new cheap switch gear ..after 74 can be used but
i like the controls to be the same on all my bikes
when the stuff on the rt125 dies it will get BMW switches
i ride 4 different bikes but like the seating and controls to be the same
so i am with my mind on the road and not where the turn signal switch is located

dave

Re: Mastiff wont start in the morning!

PostPosted: Sat Jul 30, 2011 3:28 pm
by Bodskis
Good call Dave! My mate is breaking an R65 and R45 so I'll give him a call.

Re: Mastiff wont start in the morning!

PostPosted: Sat Jul 30, 2011 9:51 pm
by DAVID THOMPSON
get the clutch lever and perch as well
then replacement levers are not a problem
and you have an adjuster at the handle bar for a quick clutch freeplay adjustment
if needed
check also the wheel calipers may change also
dave