Sputters and stalls at high speed

[dnevill]

The 2001 Skorpion Tour I got new from the dealer last May has racked up 650 miles so far. I've had problems since I first got it of keeping the engine running while the petcock is on reserve, but since I've been running it set to On the engine has been running great. I've been following the break-in procedures in the owner's manual (no more than 4,000 rpms for the first hundred miles or so, followed by a 5,000 rpm limit, and now I've passed to the stage in the break in procedures where you should keep a 6,000 rpm limit).

Now that I've had it long enough I need not worry about keeping the RPMs low, I went ahead and tried taking it out on the Freeways around 4am as I was already out cruising and far enough from home to warrant the freeways.

As I've been on surface streets thus far, this was my first time taking it above 60mph. After a quarter mile of that or so, while doing about 60mph @ 4,000 RPMs in 4th gear, the engine sputtered and lost power. I pulled off to the side of the road (luckily I was still in the far right lane) and the engine promptly died when I had pulled in the clutch and let off the throttle.

Once I stopped, with a little bit of trouble I was able to start it again. And as soon as I went past 60mph again, it started to sputter, and sputtered out a second time on me. I quickly go off at the nearest exit. Driving on surface streets going no faster than 55mph, the engine ran perfectly fine, with no signs of trouble, for the remaining 4 mile drive home.

Any thoughts on what could be causing the engine to die at high speeds when it runs fine at the same RPMs in lower gears?

[jbthumper]

just a guess...
your fuel petcock could be cloged....(reserves problem)
and your main jet might be dirty...(high rev problem)


start from the easier parts and work your way to more complicated ones...
just my 2 cents worth...

[phlat65]

also, the fuel tank may not be venting through the cap. ride it again, when it starts to sputter, loosen the tnak cap and listen for that vacuum seal sound. if no, then drain the tank, remove the petcock and inspect. I think it has a screen on the inlet.

good luck!

[dnevill]

just a guess...
your fuel petcock could be cloged....(reserves problem)
and your main jet might be dirty...(high rev problem)


start from the easier parts and work your way to more complicated ones...
just my 2 cents worth...

That's the odd part though as it wasn't a matter of how high the revs were, but how high my speeds was...in 1st-3rd gear I've run it as high as 5,500 revs without a problem (although I usually upshit around 4,000 revs). When it was sputtering out on me, it was only just reaching 4,000 revs.

I will be sure and check out if the petcock is clogged though, once I've got time to sit down with it and figure out how it's removed.

[buckwheat5679]

The RPM,s do not matter as much as the load. If you rev to 6000 in first gear you use very little fuel as compaired to 6000 rpm in 5th gear. So at 60mph you would have more load than running around in town. I would pull the tank off and check.

[DAVID THOMPSON]

FROM WHAT I AM READING BIKE IS NOS
NEW OLD STOCK NEW BUT SETTING ON DEALERS FLOOR FOR
A WHILE OR IN HIS BACK STOCK ROOM

I WOULD CHECK FUEL FILTER AND THE GAS TANK FOR CRUD
AND REMOVE THE TANK AND MAKE SURE THE TANK AND THE PETCOCK (TANK VALVE) ARE CLEAN AND FLOWING PROPERLY
MAKE SURE TANK IS VENTING PROPERLY NEEDS AIR TO GO IN AS GAS COMES OUT
PLUS CARB FLOAT BOWL FOR DIRT AND WATER
ALSO CHECK THE SPARK PLUGS
MY RT125 WAS BEING NASTY ONE DAY AND I TOOK OUT THE PLUG
IT HAD MOST OF THE TIP MISSING AND WAS STILL RUNNING
IF I BUMP STARTED IT BUT WOULD NOT START WITH THE STARTER
ALSO CHECK THE FUEL FILTER I HAVE HAD 2 OF THE OEM ONES FOR
MY RT125 DIE I NOW USE NAPA FUEL FILTERS FOR BRIGGS MOWERS

ONE OTHER THING CHECK ALL FUSES AND THE RIGHT HANDLEBAR KILL SWITCH TO MAKE SURE THEY ARE NOT SHUTTING YOU OFF

[dnevill]

FROM WHAT I AM READING BIKE IS NOS
NEW OLD STOCK NEW BUT SETTING ON DEALERS FLOOR FOR
A WHILE OR IN HIS BACK STOCK ROOM

Aye, it's "new" as it's been in the stock room for a good while. Since they started selling the 1000S they seemed to have pretty much stopped selling Skorpions. They also still have some bp or baggies in the show room (didn't get a close enough look) that don't seem to be selling especially fast.

The only place I can legally bring it to the speeds it was stalling at is back on the freeways, which are controlled access, I'd have to survive out there for at least a mile before I could get back off. I brought it right up to 60 for about 10 seconds on late-night surface streets without any sputtering, but didn't push it past that.

Nonetheless, after pushing it to 60 for that stretch and doing 50-55 most of the ride home, I removed my helmet when I got home, put my hear to the tank and removed the cap...no rush of air or vacuum-seal sounds, so the tank seems to be venting fine.

I work much shorter hours today and unless my mileage has shot up like crazy the tank should be pretty low now, so I hope to drain & check out the tank and petcock this afternoon. The all german & spanish owner's manual doesn't seem to detail that at all, but I hope to be able to figure out how to remove things on my own.

[DAVID THOMPSON]

the tanks on both my MZ bikes requires the seat be removed first
yours may be this way but i dont have a book on it

[phlat65]

whats with the 2 year warranty? it should start from the date of purchase.
don't you think the dealer should fix it?

[dnevill]

Yeah, but my work schedule has me on 10 hour days, which means I'm unavailable the entire time the dealership is open. Add to that the fact that they are not open Sunday or Monday, and that by the end of my work week then tend to have a large backup of bikes to work on, taking it into them means I'll have to wait nearly a week to get it back.

I also can't drop it off before they open or have them come pick it up from my place, as I work in a different city and I use the bike as my only means of transporation. So fixing it myself, if it's within my skill level, is definitely a better option if it's open.