MZ/MuZ Riders

Hello all,

New MZ owner here. Recently picked up a 01 MZ baggy Black Panther and am looking forward to putting on some miles, however, I have ran into an issue.

On trips, I keep having a reoccurring issue of the bike just randomly dieing. I have pulled the carbs and cleaned everything, which was actually surprisingly clean. The main needle on the left carb had a small bit of build up, but nothing clogging the jet holes. I pulled apart the CV side and all was clear there too. Diaphram was intact and everything moved freely. Due to a lack of power, I adjusted the pilot and the bike seems to be running great. I am about 4 turns out and removed the breather box to check that it was working. I am am getting fuel from the left carb and at CV is opening and pulling fuel once I increase revs.

At initial start, there are no hesitations, backfiring or any other signs of issue. The bike runs great. After about 15-30 minutes, it starts backfiring, and chokes it self out and dies going down the road. It leads me to believe that it has sucked all of the fuel from the bowl. I can choke the bike and it fires right back up and goes for another mile or so and does the same. If i pull the fuel line from the carb, the line flows free, so it seems that the petcock is fine. If i do pull the fuel line and put it back, it seems to resolve the issue for another 10 miles. I thought that the issue could be venting, but i have ran with the cap loose and it does not resolve the problem. When its not having the issue, i can ride it hard and the fuel doesn't pose an issue, the throttle is there when i need it, which tells me that float needle is working as it should and the bowl is staying full. Seems that most the time, it happens at cruising speeds of about 50-65.

When cruising, I can tell that it is about to shut off. The bike starts sputtering and backfires, loses power and then slowly dies out. I have talked to a bike mechanic buddy who used to have a Raptor and noted that he kept a stater laying because they were bad about going out and caused the same symptoms I am experiencing. I have not had any loss of electrical power and the battery keeping a steady charge.

Next steps are the stater, and draining the tank in case there is water (I have ran through 2 tanks since buying).

Any one else had these issues or have any suggestions on how to resolve? I have read through other posts, and cant find anyone experiencing the same issue, but if I missed an existing post, please shoot me the link.

Appreciate the help!

the pipe that lets air into the tank as the gas drains out loves to get clogged up over here in the usa
we call it mud dobbers little wasps that love to fill stuff full of mud its inside the lid

take the fuel tap off tank and make sure it all clean and the line is good and not kinked my 500 saxon was kinked
spade lugs get tired make sure the ones on the spark coil are tight
adjust the valves 660 motor loves to have its valves in proper adjustment

a load of no ethanol fuel if you can find some till you get it sorted

when removing tank do it out side its a big fire hazard in a shed

metal brackets fastened to tank should be left fastened to tank and removed at some other point the tank location connections are getting very fragile
and when they fail you may not be able to repair the damage

relay 30 in the wiring drawing is a major pain it carries all the power when bike is on and seems to be way too small for the load they want it to carry
dave

SOME ONE TELL HIM THE PROPER PLUG I CANT FIND MY NOTES ON PLUG

Sounds like you are losing fuel supply somewhere, but it's hard to say considering all the things you've checked. There is supposed to be another filter inside the carb itself between the fuel inlet pipe and the float valve, but I never had to take mine apart and don't know how to access it. I think you can see it when you replace the valve seat, but I've never done that either. Can anyone else confirm this and explain how to remove the float valve seat?

Also check for a negative pressure in the tank. If possible, and safe, try cracking open the gas tank filler lid next time you experience the issue to see if that fixes it.

the filter referred to is behind the float needle be careful removing the float pin

it is tapered and driving it the wrong way will destroy the carb

if I jump on this thread, I get the exact problem if im low on petrol and have to switch to reserve.

my traveller is quite the GAS HOG and 90 miles puts it on reserve
in fact i waste saddle bag space caring extra gas on trips

Thanks for the replies! Turned out being the filter above the float needle seat. Completely missed it the first time I pulled it apart.

After cleaning the filter, and installing my GPR exhaust, its running sweet!

Anyone ever find the best plug to use? Going to check valves and change the plug next.

Thanks everyone!

Hi Everybody,

I am back, saw this and thought I would post my fuel woes on the same post and ask for help. Mine has been sitting a while and just won't idle worth a darn. Runs fine, fires up and warms up with the choke on, but sputters and dies. Is this the idle jet clogged, or ?? What is my first step. Thought of just dumping in some carb cleaner/sea foam... Thanks!
This is for my '02 Skorpion tour, stock all the way.

needs a clean but remember the carb part 2 has a rubber bladder in it similar to your bing on your tour

and may not like some carb cleaners

Nozz wrote:Hi Everybody,

I am back, saw this and thought I would post my fuel woes on the same post and ask for help. Mine has been sitting a while and just won't idle worth a darn. Runs fine, fires up and warms up with the choke on, but sputters and dies. Is this the idle jet clogged, or ?? What is my first step. Thought of just dumping in some carb cleaner/sea foam... Thanks!
This is for my '02 Skorpion tour, stock all the way.

Try some Sea Foam. If that doesn't work, you may need to back the mixture screw out or replace the pilot jet. The factory pilot is too lean.

my mixture screw is backed out so far i put a safety wire on it to keep from loosing it Dave
it is at least 4 turns out

Thanks. Might ask you to send me a picture of what screw to turn! Take care, David.

edfmaniac wrote:Try some Sea Foam. If that doesn't work, you may need to back the mixture screw out or replace the pilot jet. The factory pilot is too lean.

Pilot jet replacement discussion thread
from that discussion:

edfmaniac wrote: "The Mikuni VM28/486 #40 pilot jet works. It doesn't look like the stock jet but it functions just fine and is available at almost any place that carries Mikuni jets."

I took that advice and changed mine out. Just don't tell the dealer you want the part for a MZ... ...
No more popping and I'm at 3 turns out.
BillR