MZ/MuZ Riders

Poor old Skorp got left for 18 months while I had a torrid (but ultimately unsatisfying) affair with a Yamaha Virago V-twin ..... (looked good, promised a lot - but never really delivered like the Skorp...) Today I decided to resurrect the MZ and get back to riding a proper bike.

I did all the right stuff before laying her up (steady on chaps - the Skorp, not the Yam tart ) I drained the carb, raised the bike off the ground, made sure the engine ingested a little 2-stroke premix before final shutdown (to coat the barrels with oil) etc and then stored her away in a dry garage for a year and a half under a breathable cover.

Today I gently pulled her from her cocoon, drained down the oil tank and crankcase, cleaned out the filters, refilled with fresh semi-synth and squirted a little engine oil into the plug orifice. Then, with the battery fresh off its holiday on the Battery Mate, I the spun the engine over sans plug for a few minutes to get fresh oil circulating around the stressed bits like the cam lobes. After the checking the radiator coolant level and refilling with fresh petrol, I hit the starter, and she started up on the third revolution of the motor - strongly ..... but oddly.

It sounds weird .................... but she sounded sort've flat.

Back in the days of my old manually advanced/retarded Nortons and AJS's, I'd have said the timing was too far retarded - and this sounds just like that. The exhaust note sounds like a flat bark, rather than the muted cough that is the 660's signature. She spat and coughed for a minute or so and, after running for a 10 minutes (after she'd calmed down a little) I went to wipe some oil splashes off the tail end of the silencer - and the cloth melted on the hot metal .... THAT'S never happened before - the bike's always run rather cool - and then the fans cut in after a few minutes of running.

Now give me an old fashioned magneto and I'm home and dry - but the timing on the Skorpion's solid-state is it not?

Is there some way in which the solid state timing can go wonky? If so, what does one do next?

Or is it something else I'm not seeing ................... ??????

Bob,
Good to hear your still around. How's things going up in North Wales?
Back to the bike, I'm wondering if the 2 stroke pre-mix has leaned the mixture out a bit? I'll probably face the same problems starting mine as it's not been run for 6 months. I'm putting a new Mikuni carb on it as I'm fed up of having to keep cleaning the OEM carb to get the bike to start.
Not sure about the timing? Maybe you could put an Ignitech TCIP4 on it (Bill sells them-see here viewtopic.php?f=3&t=5780&hilit=ignition) to see if that makes any difference.
Good luck.

David.

As it now sounds "flat", can I sugget you check and see if a valve has stuck open. Take off the rocker cover and see if the valves are opening and closing as they should when the engine is turned over.

It would probably be worth it to drop the pilot jet for a quick clean. Any corrosion or particles in there can lean the bike out and make it idle hot. Might try some Sea Foam first too. I put it in the gas and oil for a hundred miles or so and then do an oil change.

Good stuff gents - thank you. I think a carb drop's in the frame this weekend. I have a feeling that, despite stripping and cleaning the thing before storage, this petrol substitute we're having to use might just be the culprit.

I have to admit, Bill's ignition kit is tempting .....................................

Hi Bob,
Another welcome back.
Ahhh, the "fond" memories of my buddy's Virago...
Similar issue with my Traveller on the way home when I bought it. Had sat in the garage for about a year. Good carb cleaning and all was better. Also needed a new fuel stopcock, wouldn't flow well when it got near 1/4 tank.
No ignition issues to date...knock on wood...
Bill R

Got impatient and decided to play engineering this afternoon, so set to with fine grinding paste and my modelling lathe and restored the float valve seat. I fitted a new 'O' ring from a box I keep for my other hobby of building and tuning pneumatic rifles (not to mention shooting game with 'em and then putting the results into a large cooking pot .... ).

Result? The carb's now leak free, the float level's correct and the bike now runs perfectly again.

Can I put a finger on a hard fault? Can I fly?? I can only surmise that the float assembly was sticking for some reason, that my polishing and reseating has now cured.

So, I'll book an MOT next week, and have a swift pootle to see if the old girl satisfies HMG's inspectorate. Then I'll probably scare myself witless on the way home ..............

Thanks for the info gents!!!

i have found that pulling the trigger on an air rifle is ...better
than scaring your self pulling the trigger on a well tuned 660
my traveller goes fast enough i do not let crazy friends take test rides

dave

had a similar issue with mine recently...pulled the idle mixture screw for the pilot circuit and sprayed it with carb cleaner inside...pilot was gummed even though I use seafoam...it did sit for 6 months and run dry befor storing
just junk in the crap gas.......runs fine now settles at 1350 smoothly