Problem: Friday, after finishing work, I was riding home.  Bike has had none of the following issue untill now.

In 3rd, going down slight decline, doing about 70-80km.
Bike gives sputter and dies.
Coast to side of ride and turn off and get off bike.
Look for any oil/petrol leaks - none
Look for any vac hoses; fuel lines no longer attached - none.
After 5 mins of standing on side of road with much verbal abuse directed at now defunct m/bike, try to restart bike.

At first nothing, turning over but no ignition of fuel.
Pull out choke, try again - same result.
Turn petcock to prime for couple of seconds, bike splutters into life, turn petcock to ON and idle for 5 minutes, everything seems fine.
Get to beginning of highway about 1km up road from first point of failure, bike still fine, get halfway up the hill (so now bike is in incline) in 4th doing about 90-100km bike dies again.
Pull into offroad, call wife to bring trailer and take bike home.
While waiting, try bike again.
Starts after awhile, ride up & down fairly flat road, 1st-3rd gears all good.
Decide not to keep riding, and take bike home on trailer.

Work done so far:

Bit the mechanical bullet and began my first ever bit of mechanical work ever.
Hooked up PC in garage and loaded up clymer manual.
Removed seat, fuel tank, disconnected battery, and removed carby.
Stripped carby to barebones.
Should mention here that about 2-3 months ago I overfilled bike with oil.
Bike ran fine in spite of that.
When stripping carby, there was small amount of oil sitting in the diaphragm assembly.  But no where else.
So far so good.
Cleaned everything, put everything back together.

Pulled battery to check while bike in bits.
Very low, topped up charged, reinserted battery this morning.

Put carby back in bike, triple checked everything back in it's rightfull place, and tightened up.

Pulled out air filter, still in good nick.

Primed carby, and after couple of attempts bike kicked over, sounding better than ever.

Took bike for blast up good incline hill at bottom of driveway.
Thought I heard some hesitation, but made it to turnaround point about 2-3km up the hill.
Coming back down hill all seems fine, until bike gets to steepest decline, 4th gear, about 90-100km, bike sputters and dies again.

Coast to driveway, bike won't start until petcock in prime, then once going, turned back to ON and driven up to garage where it now sits in shame.

Oh at this point I also removed petcock, looked for any blockages, none found.

Any ideas before it goes into dealership tommorow?

I'm with Versy,... sounds like the vac line is leaking air...

should run okay on prime,... if it does, replace the vac line and attach firmly with clamps...

Oh and could any one tell me what I should ask for from my local autoshop exactly, when I ring to get price and availability of the vachose?

Repco, the Co. I will go to, is mainly about cars, and most the staff wouldn't know a moped from a harley, so I won't assume they know what type of hose I am after on the phone.

I assume without checking it's about 6mm rubber hose?

wolfmrp wrote on 05/15/10 at 19:18:26:


yeah that is the obvious route, but I will be at work, no vehicle, so will go after work, when wife picks me up.
Wanted to make sure they got it instore first.

Is this what I am after 'SUZUKI 09352-50823-600 HOSE,5X8.2X600' &
'SUZUKI 13318-24C00 HOSE ASSY' (but just the hose)

Also on top of the carby there are 2 hoses that go up and tuck under the tank.  Are these 2 hoses just vac hoses or something else.
see part 39 here There is another on opposite side.

Mine was doing something similar.  try running with petcock on prime.  if that works your vacuum seal in the petcock is bad and you have to get another petcock or just run on prime and keep an eye on your mileage because you don't have a reserve any more.

LOL I told ya so.

I rang the auto store, got the part numbers for the correct id for both hoses, went to the store, and guess what, 'oh we don't have the 3 metres the computer shows, here have some completely different hose for free'

Well needless to say I took the free hose, and went home and reassembled bike with old hoses, turned petcock to prime and went for 10 min ride on highway.

Bloody marvelous it was.  Nothing went wrong at all.
Got home, turned petcock to ON and parked up bike for night.

Tomorrow morning will be the real test.  It's 37km there or bouts to work, almost all state highway.
If I make it to work with no issues then problem solved, and new petcock will be ordered.

If it is solved then thank you all for the suggestions, and I am still going to replace the air & petrol hoses.