MZ/MuZ Riders

Hi there

I am wondering if some kind person can throw any light on a problem I am having with my 1995 Skorpion Sport. I had laid it up for over 18 Months and am now trying to sell it. The battery was shot (which I expected) so I replaced it with a nice Varta YB14L-YA2 expecting it to just crank over like a demon having previously refurbished the starter motor also sometime back. It used to crank really hard. Unfortunately this was not the case. I just heard a dreading single click from the starter solenoid. I know the battery is full charged OK as it charged all night on my optimate and is giving a healthy voltage. When I press the starter button the voltage drops but wont crank the engine. The leads are slightly warm so I know its drawing current.

Next I tried bumping it to ensure the piston wasnt seized. I know there is a lot of compression on these bikes so by experience they dont easily bump. Back wheel turned around a quarter then locked so I persisted with the same thing happening. I could not free wheel it whilst in gear with the clutch pulled. So I am at a loss to know whats wrong. I was expecting to free wheel it in gear then let out the clutch and attempt to bump it. But it just behaved as if the clutch was out and in gear still. It free wheels if left in Neutral OK

I dont know whether to sell it as seen or spend more money getting it Going. I spent a lot of time and money on it approx three years ago refurbing the back end. I replaced all the bearings and had the swingarm and rear subframe powder coated and finally installed a Penske 8981 fully adjustable shock which transformed the rear end a treat.

I am open to advice

Regards

Stu

Where are you based you say south wales anywhere near Porthcawl?

Tried tapping the starter lightly - it may be sticking?
The clutch sounds like it is sticking, the 660 has a dry dry sump so clutch easy to look at
As noted above 660 has a dry sump, has the oil drained to the sump - check oil level in reservoir at correct level

Ian

Hi Ian

many thanks for your quick response. I am based in Chepstow, a little while away from you. I checked the oil and there is plenty in the plastic reservoir. I would like to sell it working, with a current MOT if possible but am now out of my comfort zone. If the clutch has seized is it much of a problem to fix.

Regards

Stu

Clutch easy to look at - right hand casing
Worth having a look as there is not a lot to stop the bike working

I would also take the fuel tank off and take the plug out, put couple drops of engine oil in the piston and turn the bike over.

Hi

I tapped the starter carefully but did make much difference. Whilst bumping it earlier it did turn for about half a second. But have not been able to budge it since.

If I take the clutch cover off will the oil all leak out. And what would I be looking at as far as the clutch goes. I will try and put a little oil in the plug hole.

Ta

Stu

Pull the spark plug......no compression. Bump it by pushing first. If the bike does not turnover....U have other problems. A good idea to place a little oil in cylinder before turning over.

Good luck.

mmm plates difficult to describe just check plates disengage and engage when the clutch lever is pulled in and released.

Turn the bike over with the plug out, no resistance obviously with plug out or put in 3rd or 4th gear and push bike to ensure all is moving, I can pop up in two weekends time to have a look

Thanks Ian. I shall try the things you advised and let you know.

It does sound like the piston is seized in the cylinder, try spraying some wd40 into the bore and leaving over night. Then try to free the piston by rocking the bike in gear without the spark plug in. Once free squirt some oil into the bore before turning over with the starter.

Thanks radiograf. I shall try all these things and repost

Would this still be the case (piston seized) if you were unable to move the bike in gear with the clutch both in or out.

did you try the bump in second gear
i have had almost no success bumping any bike in first

the starter brushes may not be seating against the armature contacts properly after that long of a set

also your clutch fiber and metal plates may be stuck together

You might have a hydraulically locked cylinder - one filled with gas/oil to the point that it can't turn over; this would explain why you could turn it over to a point using the rear wheel. Regardless, definitely the next step is to pull the plug and try turning to over then.

Clutches can seize up like that over time easily; I'd treat that as a separate issue. When you do get it running remember its seized the first time you drop it in gear!

Sam

Thanks guys. I am trying to learn as I go along so appreciate the help you give to aid me in repairing this issue.

Right then, I have stripped fairings and tank and removed the plug spraying some WD40 to leave overnight. I shall try rocking it in the morning. And progress from there.

If the clutch has seized how should I tackle that problem.

Stu