MZ/MuZ Riders

Bought a Silver Star 2 weeks ago. It hasn't been on the road for 10 years, so there is a few things to sort out. I've changed the oil and oilfilter, the cambelt and "cleaned" the carbs plus som other things.
The bike started first try, and idles fine. But when I drive it up and down the road, it looses power at 2500 - 3000 rpm and makes a strange noise. I tried the choke, but that makes it even worse. Any suggestions?

I cleaned the carbs "so and so": Took of the bowl, it looked relativly clean. So I sprayed carb-cleaner in all the holes og blow through whith compressed air. May be I should have done a more seriouse job?

Tor Johan

my saxon tour has a bing cv carb

had a problem with it running one day it was the fuel line had a kink in it that shut off the fuel
hose routing was a bit cramped
is the metal cap still om the plug cap have had a lot of problems with the metal cap on my bmw bikes
there is a filter on the fuel shut off (petcock) it must be removed to be cleaned
dave

The fuelline is ok, but the plugcap is the old one i metal. I'll change it!

As you live in Norway, i wonder how high from sea level... maybe you need replace jets in your carb.
On the other hand, most common reason for bad running engine is sparkplug

viewtopic.php?f=26&t=827

in mine the D8ea does not work very well

dave

Hi
I live near the coast, så that is not the problem. I use the sparkplug from Denso that matches NGK D8EA. But i dont think that is the problem either. I've just cleaned the carb, but could not find anything wrong. The only thing i did not check was needle hight. I think i have to do that! When the bike has a new, clean sparkplug, it runs great for 10 minutes. Then, the sparkplug is black

I have ordered a new air filter. The bike has been stored for 10 years so i think it is time to change it.

What carburetor do you have? Dellorto PHF34GS? If so, make sure the "choke" cable has adequate slack (2+ mm) and check the choke valve (bottom piece of #90 here: http://www.dellorto.co.uk/images/parts/PHF.PDF ). There's a rubber seal on the bottom of it, if the seal is cracked or otherwise damaged it will allow extra fuel to be drawn through the carburetor independent of throttle setting.

I have Bing carb. The bike runs well below 2500 rpm and qiut well above 5000 rpm. I've checked the choke wire, and ItS not the best.... I have to push the choke off by using my thumb on the carb
But I dont think that is the problem.
I'm waiting for a new airfilter element from Germany. I think i will changed it, before i move on with adjusting the needle hight....

filter from bmw chopper fits if you make an adapter
dave

Did you ever get this sorted? My bike is doing the exact same thing.

Hello.
Yes, the new airfilter made a big difference. The old one was soak with oil, and made the bike run way to rich.
I also changed the front sprocket to 1 tooth less (don't remember exactly how many...) and that made the bike run
smoother at "town-speed". To my experience, you have to keep the engine between 3000 and 5000 to make it run smooth and that means alot
of gear-changing...

My problem was an oil soaked air filter as well, plus I will be changing to a 16t engine sprocket.
Thanks for the follow up.