ETZ CARBURATION #2

[Andy_C]

Can anyone tell me the correct float heights for a BVF 30N3-1.

I fitted a replacement float along with new jets and needle now it will not even fire !!

Plug looks to be dry so suspect no fuel getting through so suspect float height may be wrong.

Plenty of fuel in the bowl when I take it apart but is it at the right level ?

Thanks.

P.S. Now the bl**dy kickstart ratchet has given up the ghost. Grrrrrrrrr

[Blurredman]

Gotta Love MZ's... Whenever I have to buy a new part (like a new kickstart spring) I buy two so I have one on the shelf ready for when it inevitably happens again!!


The official manual states:
The measurement should be 27mm when upside down, and 33mm when the carb is upright.



BTW, I have the original manuals and the haynes on my FTP Site for future reference.

ftp://www.blurredmanswebsite.crabdance.com/ within the 'Vehicle Documents/MZ' directory

[Andy_C]

Blurredman - really appreciate the info.

Took the primary drive cover off tonight to try and find the source of the problem.

Looks to be because the teeth on the ratchets are rounded off.

Return spring looks OK, sliding pinion moves freely enough guess that it has to be the ratchets.

Yet another to send to awell known MZ shop

[Andy_C]

A footnote to this.

The ETZ that I got back in March this year is now well and truley sorted.

Starts reliably 1st or 2nd kick, hot or cold, performance is a bit down on the 301 that I had but not enough to bother me.

Apart from fixing the kickstart ratchet, giving the bike a damn good clean, and replacing a few worn out bits, the biggest single thing I did to make the bike run well was putting the carb through an ultrasonic cleaner. The boiling lemon juice trick cleaned out a lot of the crud and made a lot of difference but the ultrasonic cleaner has made a massive improvement.

After the ultrasonic clean the surging that I used to suffer has all but disssapeared - chain tension is also another factor (besides mixture) that has a big effect on surging.

It also seems to run better on super unleaded.

Very happy with it - might even make a little you tube vid of me riding it. If I do I'll post up a link.

[Blurredman]

Hi,

I'm glad your bike is running well. My recently required '90 ETZ 251 has only just started to be a reliable bike after purchasing the following (as things I HAD to buy because they were broken/damaged)..

New Clutch engine cover w/ Kickstart,
Replacement Coil,
Electronic ignition,
Rear tyre,
Various small components I had spare (round etz 250 lamp), bulbs, fasteners, etc.


I calculate I have spent so far £250 (for components, not including tax, insurance, mot, transport) on a bike I only paid £100 in the first place. Not to mention I am currently using a borrowed 250 barrel and piston because the original was rust seized. Will need to get this sorted soon. I will also have to buy a new main footrest as the left foot rest bent and sheered away from the mount. So far it's held on with a rode in between the fixing and some string keeping it up, but that's only good for short term, really..

Trying to get it running on as litle as possible. Fix only when broken sort of thing.


It's only taken me 11 months to get the bike into a state where I can have full confidence in it's ability and reliability. Used to break down at least 3 times per commute to work (and the same amount coming back). I'm glad I persisted now.. It feels great when it's finally running right and well! Definiately doesn't have as much torque as my ETZ250 though..