Hello from noobie, ETZ251, yorkshire uk

[treehouse]

Hi, I just got my new bike home yesterday, a 1993 Saxon Tour, and hoping I've done the right thing. It felt plenty powerful and handled nicely, but the juddering on closing the throttle, or just easing off it a bit, seemed like it couldn't be normal - not just "that thing 2-strokes do". I had a Suzi GP100 that made a polite pinging noise, but this felt like it was going to shake itself to bits at one point. The previous owner seemed to have two explanations - that it needed a good run to clear the muck out - and that that's what these 2-strokes do and you have to ride it out of corners on the gas. But surely you have to use the engine brake, or just ease off the gas to slow down a bit?...oh well, maybe the hour ride home wasn't enough to clear the muck yet. It didn't tick over after I got it home, either, although it did as sweet as a nut in his garage. I'm a bit scared because I did everything wrong - went to see it after dark, got chatting and failed to check it over properly, formed the opinion that the guy was a super engineer and all-round good egg, didn't take it for a test ride (or I'd probably not have bought it) and then probably paid over the odds.

It was at least a comfy ride after being concertina'd into my CBR125, I had to hang on tight when opening it up, it'll take some gear without complaining, and I should be able to do some of the work myself. It's a bit tall for me - I might have to lower the seat. Thanks for the great forum - it's been good lurking while I was researching these bikes.

[Skorpion]

Hi treehouse.

Congratulations on your new MZ.

Yes the 250 & 300s have a tendency to lurch on a closed throttle, but with careful adjusting of the carburetter you should be able get it to be almost lurch free.

You could have the Bing carb which I know nothing about, or the BVF with the spring clip holding on the float bowl, and both adjusting screws on the right, the setting up of this carb is for me a black art, and something I never mastered, but with perseverance you should be able to set correctly.

You need to get a reliable tick over as near to 1000 RPM or just below as you can, this will stop any lurch on a closed throttle.

Where abouts in West Yorkshire are you, I'm very near to were the Yorkshire section of the MZ Riders Club meet in Cleckheaton.

[treehouse]

Hi treehouse.

Congratulations on your new MZ.

Yes the 250 & 300s have a tendency to lurch on a closed throttle, but with careful adjusting of the carburetter you should be able get it to be almost lurch free.

lol - that'll be fine then

You could have the Bing carb which I know nothing about, or the BVF with the spring clip holding on the float bowl, and both adjusting screws on the right, the setting up of this carb is for me a black art, and something I never mastered, but with perseverance you should be able to set correctly.

You need to get a reliable tick over as near to 1000 RPM or just below as you can, this will stop any lurch on a closed throttle.

Cheers, I'll have to inspect it when it stops raining. As the guy was making up a little doggie-bag of spare plugs, spanners and oil, he showed me a long spring, which he said was out of the carb - he's taken it out because he reckons it's better without - it returns it too quickly and makes the throttle control a lot stiffer, so whether this makes the lurching worse I don't know. He warned me that the downside to this is that if you give it full throttle there's a danger of the jet coming right out of position. I do get a bit fed up of throttles that have very stiff return springs or whatever, and your right arm gets tired after a while. It did seem nice and light compared to my 125. I'm kinda looking forward to delving into the black art now, thanks to your encouragement.

Where abouts in West Yorkshire are you, I'm very near to were the Yorkshire section of the MZ Riders Club meet in Cleckheaton.

Them's fighting words - I didn't say I was in west yorkshire! I'm in the posh bit - Harrogate, North Yorks. I'd like to come to that, though.

[Skorpion]

Hi treehouse.

Sorry about the West Yorkshire, We all know North Yorkshire is best or it would be if it wasn't so posh.

You should definitely have a return spring in the carb, it could get trouser staining if it sticks open.

Good luck with the fettling.

[snuffpig]

Hi Tree House,

I have a 301 that used to lurch on the overrun. I solved 99% of the problem by using a c-spanner to tighten the exhaust nut on the downpipe!

I followed advice on this forum to lower the tickover 1000 rpm but my 301 would occasionally stall at lights when it was that low. Mine is now around 2000 rpm tickover (according to the clock) and it's very stable; I use it for commuting daily. YMMV.

They're large(ish) 2 stroke singles so a small amount of lurching is probably always going to be there, but it should not be dramatic and just part of its character.

You can hear my tickover at 15:11 (and other parts) on this video here:
https://www.youtube.com/watch?v=9JUPKOaQU6E

My tickover put to the test here: https://www.youtube.com/watch?v=h1HD_NgLEWU

[treehouse]

@snuffpig, that's useful information about the exhaust nut. Actually, one thing he gave me is the spanner for that, and he said it was worth checking it every now and then and tightening it up. I also noticed when I went to look at it that there was some liquid weeping from there - I asked him about it, thinking it might be an oil leak, and he assured me that was normal. I took it on trust. I don't know if it is, but anyway, I'll keep an eye on it. Interesting videos - you demonstrated one of my nightmares, stalling at a junction because you've forgotton to put the fuel on. In fact, I'm scared enough of just stalling with fuel in the line and having to kick start it, but I'll no doubt get used to it - not done it with my left leg yet, and with a 28" inside leg, I'd be on my tip-toes on the other foot! I'm used to just pulling the clutch and pressing the red button - didn't realise how lazy I'd got. I guess you've got to fit it into the pre-ride routine we all use. You also reminded me that I never thought to put the fuel off after getting it home, so thanks, I'd better go and do that now. He also said it should tickover at about 5 or 600, but I'll increase it. He gave me a Haynes with it, but I've not had chance to read it yet.

@Skorpion, yeah, it was a bit alarming when he put a bit of the bike in a carrier bag for me in case I wanted it. I tend to think MZ had a reason for putting it inside the carburettor.

Thanks guys, great to have your input. I'll no doubt have a lot more questions for the techy bit of the forum later.

[DAVID THOMPSON]

Haynes with it, but I've not had chance to read it yet.
Do not READ IT
the English guys call it Haynes little book of LIES
and i have found so many mistakes in the BMW version i can understand why

i hide mine so visitors do not read it
for there safety
dave

[treehouse]

Do not READ IT

Haha, yes I've seen that about the Haynes - very annoying that you don't know where the mistakes are - makes the whole thing virtually useless! It might be a bit of help in guiding me on how to take the carburettor off and put a spring back, until it comes to setting it up, and then I won't trust the numbers of turns of screws and suchlike. I've read that the official works manual from MZ is exceptional. I'll look out for one, especially if I start delving deeper into the critter's guts. For now, I'll go by how she behaves, or ask for help here. It's under a tarp with an inch of snow on top of that at the moment, I've got a pig of a cold, and even if I didn't, I haven't got time to work on her. Oh no, I've started to call it "her".

[DAVID THOMPSON]

Oh no, I've started to call it "her".

there just like a red headed girl friend you fall in love way too fast!
dave

[therealche]

Greetings from the Peoples Republic of South Yorkshire!
Well I'm here at the moment but will be going back to West Yorkshire soon
Get yourself a real MZ manual from the MZ Riders Club they are well worth getting.