With my old Supa 5 in the 80's it was suggested I cut off the cone end of the exhaust to improve gas flow.
Yes it revved much better.
If you have ever seen inside an original Supa 5 exhaust you will understand why it is so heavy.
A labyrinth of tubes to cut noise and slow gasses.
Roll on 37 years later I have my ETZ 250.
When I bought it and rode 50 miles home it did not seem as lively as the old trusty TS part of this is the porting being so different between models.
So.…….
The pattern exhaust did not sound right a bit restricted in ring ding ding sound and gas release.
I got one from Kultmopeds off Ebay and it does not have much baffelling inside so very light.
The bike had an original yes original 1990 mz airfilter that had seen better days.
I ordered a new one and decided while waiting for the new one to arrive to fit a K & N panel filter I had laying around the garage. I rolled it up to fit inside the airbox and it sprung loose to fit really well.
There was concern with not enough back pressure and too much air with getting a holed piston - had enough of them on my RD400E - but had a go
There is a lot talk about MZ's bucking on the overrun so I adjusted the mixture screw and along with the air filter and exhaust change it is almost none existent.
Took it for a run and it ran a lot smoother I guess because of the extra air flow it just felt crisper with throttle response.
It sounds like an MZ should and along with the electronic ignition I fitted it is much happier running.
Yes I checked the plug colour and all is fine. As it is a low revving engine it should be alright.
Not done this to gain speed or power just day to day running feels better and easier to ride.
I did this last year and it has been great fitted the ignition this year and still going great.
I did put the new correct air filter in but it felt strangles so took it out.