Even the shop is stumped

[calibellus]

Perhaps the maintenance gurus can come up with something, because at the moment, my shop is stumped.

The situation: 2002 MZ Skorpion Tour. It's brand new, but has been sitting for the past two years and a bit in a dealer in Colorado. I had it shipped to Calfornia to an MZ dealer, SF Moto, who got it registered with the state (doable since it's a 50 state bike and had never been registered out of state), and who prepped it. They replaced all the fluids, did a basic checkout, and said 'it's ready to go'.

A friend of mine agreed to ride it over the Bay Bridge to Berkeley. I wasn't going to have that be my introduction into street riding. Unfortunately, the bike died on the bridge: stalled out, wouldn't start. Caltrans towing got the bike back to the shop, and after it'd cooled down, it started up fine, only to die five miles away from the shop when it'd got warmed up again. (This time with a mechanic aboard, fortunately.) The symptoms are that it starts fine, hesitates more and more as it gets warmed up, and then dies and won't start again as it gets fully warmed up.

The good news is that MZ's handling this under warranty. The bad news is that neither the shop nor MZ Motorrad NA is sure what's wrong. They've checked out the fuel flow and the valves. Current thinking is that it might be the ECU (? The service guy called it the 'black box'. This makes not a lot of sense to me, since it's a non-FI bike, but maybe it's something like an emissions controller?) They've ordered one from MZ, but it's 5-8 days to ship via UPS. Mean time I'm still without bike.

Anyone have any ideas about what this might be?

[Anders-MZ]

I had the same problem with my Yamaha XT600E when it came back from the workshop and the 18000km maintenance.
The new sparkplug was bad AND the mecanic hadn't tightend it properly.
Good luck!

[hulagun]

I doubt it's the mechanics fault.

The first thing I'd look at is fuel supply, or tank venting, but that's so basic they must have done so.

It sounds to me like the 'black box', basically the 'brain' for the electronic ignition, controlling the advance curve among other things. These were known to go bad once inna while on the older air-cooled Yamaha singles, so all the Yamaha singles racers I knew always kept a spare handy. One spare... as in they just traded it around if one of them needed it!

If they haven't done so, I would urge SF MOTO to borrow one from a known good-running 660 bike and try it in yours. It's plug and play and cheaper than trying out every other option first... Then you'll know for sure without waiting a week.

Relevant to this - don't toss the old black box. I'd like to see whether it would still serve as a good donor for the racing ones sold in Germany. If so maybe I can buy your 'bad" one. (UPDATE 10/20/04. NO...a bad CDI is just that. Bad. oh well.)

Keep us posted as whatever you find out will be helpful to one of us in the future.

Ivan in SF

[keithcross]

I'm not sure if teh MZ works the same, but I have seen this problem before on some Hondas. On them its normally th pick ups on teh crank breaking down once they get warm. I have also seen this happen on an ignition coil. Once warmed up a crack in one of teh winding makes the coil go open circuit.

Keith

[Dezmo]

have you tried checking spark when the bike is warm? if theres a break in the ign coil it might work when cool but when it warms up and expands some the broken spot loses contact, and the motor loses spark...of course I could be totally wrong, but its worth checking.

[motardina]

Perhaps the maintenance gurus can come up with something, because at the moment, my shop is stumped.

The situation: 2002 MZ Skorpion Tour. It's brand new, but has been sitting for the past two years and a bit in a dealer in Colorado. I had it shipped to Calfornia to an MZ dealer, SF Moto, who got it registered with the state (doable since it's a 50 state bike and had never been registered out of state), and who prepped it. They replaced all the fluids, did a basic checkout, and said 'it's ready to go'.

A friend of mine agreed to ride it over the Bay Bridge to Berkeley. I wasn't going to have that be my introduction into street riding. Unfortunately, the bike died on the bridge: stalled out, wouldn't start. Caltrans towing got the bike back to the shop, and after it'd cooled down, it started up fine, only to die five miles away from the shop when it'd got warmed up again. (This time with a mechanic aboard, fortunately.) The symptoms are that it starts fine, hesitates more and more as it gets warmed up, and then dies and won't start again as it gets fully warmed up.

The good news is that MZ's handling this under warranty. The bad news is that neither the shop nor MZ Motorrad NA is sure what's wrong. They've checked out the fuel flow and the valves. Current thinking is that it might be the ECU (? The service guy called it the 'black box'. This makes not a lot of sense to me, since it's a non-FI bike, but maybe it's something like an emissions controller?) They've ordered one from MZ, but it's 5-8 days to ship via UPS. Mean time I'm still without bike.

Anyone have any ideas about what this might be?

This is going to sound stupid...but check it out anyway, 'k?

I bet your oil level is too high! No shit, the baggy we got from astoria OR MZdealer (same engine remember!) had this EXACT SAME hot start/bogging when hot issue that you describe! It was finally tracked down to the fact that the oil level was too high.

The MZ 660 engine is really oddball (compared to wet sump engines) when it comes to filling after an oilchange--the MZ dealer we bought our second one from overfilled the oil by not following the stated procedure...which is to ignore the fill markings on the dipstick, fill with *no more* than 3.5 liters of oil, with filter change (it actually takes less than 3.5 liters..more like 3.2 or it gets overfull and no oil shows on the stick yet!) then start the engine, open bleed screw on oil filter to bled the air out, button up and run till warm--- *then* check the oil level after idling 30 seconds immediately after shutting off! And add oil if necessary.

Now what this astoria dealer did was immediately fill the oil in the cold bike after the oilchange all the way to the full level on the dipstick--if you do this--and it's a commoner mistake than i think many admit to-- the engine will be WAY too full of oil when it hits operating temps and will stall and refuse to start when warm. we drained out about a *quart* of extra oil (no kidding!) and after this the bike ran & started hot cold whatever, just perfectly. we first got a hint of the issue when we opened the dipstick cap when the bike was hot and the oil just *poured* out of it.

We don't know exactly why oil level afffects the bike like this but think it has something to do with pressuring the oil system and tying up the engine somehow in that way..

Might not be your problem, but i'd sure check...oddball thigs like this are too often just automatically assumed to be right and people immediately start looking deeper at all sorts of things..and thus miss the simple stuff. Can't tell you how many times i have seen mechs (including me) caught out like this...automatically getting sidetracked looking for a deeper problem without first checking the obvious.

[phlat65]

i agree with the oil level. also, hesitations that get worse mhen warming up are usually jetting, or fuel supply. secondary ignition will seek the easiest path to ground, so the greater the load and heat, the more prevelant a miss will become.

have them check the carb diaphrams for cracks, or contamination of the carbs..

don't worry, once you get to ride the bike, you will fall in love with the mighty MZ

(currently finishing off a great german beer, so if I start to blabber....)

[dthemic]

Michael,

Sorry to read about the problem. But, I am sure it will prove be something simple and as of yet just overlooked. With basic diagnostics it should not be too difficult, especially since the condition can be duplicated. Make it quit again and check for fuel in the bowl and spark at the plug. Gotta be one or the other.

Once the wierd shit is sorted out you will love the bike. I think most of the folks here will agree and most all of us have had some strange stuff to sort out.

Post an update. Is the bike on the road? How has MZ handled warranty support? Is your dealer willing to do the work under warranty? As sometimes getting paid for diagnostic time under warranty can be difficult. How do you pay a guy to go ride a bike in traffic until it quits and then start diagnosis along the highway.

Just my two cents. Good Luck.

Dave

[calibellus]

Post an update. Is the bike on the road? How has MZ handled warranty support? Is your dealer willing to do the work under warranty? As sometimes getting paid for diagnostic time under warranty can be difficult. How do you pay a guy to go ride a bike in traffic until it quits and then start diagnosis along the highway.

Just my two cents. Good Luck.

Thanks. It's been a little over a week, and I'm still waiting. At the time, they'd ordered a new CDI unit from MZ, and it was going to take 5-8 business days to arrive. (UPS ground. Feh.) I talked to them on Friday, and relayed several of the suggestions that'd been given to me. They were:

1. Fuel tank air feed blocked.
Checked. Not a problem.

2. Bad coil.
Checked. Coil appears good.

3. Bad CDI unit.
New unit ordered, awaiting delivery.

4. Oil tank overfull, causing engine to die when oil heats up.
Left a message suggesting they check this.

The good news is that all parts and labor are being handled under warranty by MZ. The bad news is that I don't have my bike back yet. The guys at SF Moto have been pretty cool about it, particularly with me calling up late last week with a bunch of suggestions. (I do computers for a living, and I loathe people looking over my shoulder when I'm troubleshooting.) That said, I do wish they'd pulled the CDI from the Baggy they have in the shop and fitted that out. I can understand why they wouldn't: they can't sell the Baggy while it's down and disassembled, and I didn't buy the bike from them. They feel bad about what's happened, but it's not their fault and they're not the original dealer. Given that I got the bike from a place that'd gone out of business, and that's out of state, I suppose I should be grateful that both MZ and SF Moto are being as cool about the expense as they are.

I plan to call them tomorrow to find out what the status is. If it's the CDI, I should get it back early next week. If it's not the CDI, then who knows.

[calibellus]

The saga just keeps getting weirder.

Earlier today, the shop called me up asking about parts, specifically, how I wanted them shipped. This made no sense to me, since it's being handled under warranty.

Not so fast.

After talking with a Baggy owner (perhaps our own hulagun?) they took apart the fuel system just to double check that everything was fitting correctly. What they found just stumped them. According to the shop, they found a jet valve inside the fuel line. Someone had actually shoved it up inside there. This drastically reduced the amount of fuel flowing down into the system, which explains why it kept dying. Fuel would (slowly) drip into the engine, pool (in the bowls? engines aren't my thing), and then get used. When this small reservoir was used up, the flow from the tank through the jet valve wasn't enough, and the bike would stall and die.

Next question is why would someone do something like this? The bike is new (25 miles on it when I got it), and never registered. Any service should be under warranty to begin with, and if there was a problem with the bike when it arrived from the importer, it should have been handled at the time. Unfortunately I can't ask the original dealer, because the shop in Denver is bankrupt. (I talked to the former owner, but he got the bike with the shop, which means anyone who would know is two transactions ago. No luck. Keep in mind that SF Moto just received and prepped the bike; they're not on the hook for it.)

Worse, the jet-up-the-fuel-line was probably a really bad fix for some other, as-yet undiscovered problem, which may not be fixable under warranty either if the same genius who shoved the jet into the fuel line did something else at the same time. God only knows what else they'll find in there, but the service manager said they'd found some silicone sealant around the carbs that looked suspicious.

Tomorrow I am going to call MZ and ask them what the hell. I am also going to try to figure out how much money I can spend at this point to get the bike on the road, once SF Moto comes up with an estimate of how much this is all going to cost. SF Moto has also ordered a new gasket, and they're going to examine the carbs and engine more carefully to try to figure out what might have caused something like this in the first place. Presumably if they needed to restrict the fuel flow, the engine was getting too much fuel when it was running, so there's something else that might be wrong in there.

At the moment, I am finding this to be one of those 'if it looks too good to be true' situations. I'm also wishing I'd got a Ninja 500 and thrashed the hell out of that for a while. At this point, it would be costing me less than a new 500 with a functional warranty, no wackiness in the fuel system, and I would have had it two months ago.

The thing that's hacking me off the most is I haven't done more with the Skorpion than sit on it. Once.

[phlat65]

probably some "genius's" miracle fuel mileage device. but seriously,
these carbs have been known to fill the air box with fuel when not used, maybe that happened, and this was their solution. the shop could still start and run the bike for potential customers, but it would be less likely to flood. just a thought

[calibellus]

probably some "genius's" miracle fuel mileage device. but seriously,
these carbs have been known to fill the air box with fuel when not used, maybe that happened, and this was their solution. the shop could still start and run the bike for potential customers, but it would be less likely to flood. just a thought

That's a good thought. I'll talk to them about it. They're still probably going to want to check the engine in detail though, and I don't really blame them. (I don't want it stalling dead on the Bay Bridge again! )

[hulagun]

Hang in there. SF MOTO is a good shop and this situation is probably just as much a PITA for them... but that's what they get paid for.

It sounds like they have found a very likely culprit... that fuel line blockage... unless, as you said, it was a 'fix'. It just sounds like assembly-line sabotage to me. Hopefully now the blockage is gone the bike will run fine.

When you do pick up your bike, try to do it in the AM so you can immediately go for a 50 mile "get acquainted" ride. Get a promise from the shop that if it stalls again that morning, they will send their truck (or Dave's Cycle Tow) to retrieve you... at their expense, or at 50% shared cost (which seems more fair to me). Take your cell phone.

And be sure you are very familiar with correct starting procedure plus how to turn the gas valve on correctly (including use of reserve). It would be really embarrassing if you made them tow you in, and it turned out it was (this time) something you did wrong!

If the bike runs fine - be sure to let the shop know. That way next time you call they won't assume it is bad news.

Good Luck!
Ivan

[keithcross]

Could well be sabotage, either in teh factory or in one of teh shops it has been in. I bet some mean b'stard will be laughing if he reads this thread.

Keith

[calibellus]

Got the Skorpion today. They found a main jet stuck up in the fuel system. Very strange thing. But that removed, fueling works, and it's now sitting in my driveway, up on its centerstand, waiting for tomorrow morning to be taken out. I even got a short neighborhood ride on it, and while I definitely need some practice, I didn't drop it and it worked just fine.

Thanks for all the help, everyone. Finally, I'm actually an MZ Rider.