13 HP winsun broke down..

[arnaud]

..yesterday on my way back from Hamm..
trundeling along at 85-90 kph (top speed 100kph says navi device)
Sudden loss of power, strange noise, a LOT of blue smoke..
No compression anymore
My first guess is a pissing injector and so piston damage.
The same day, the bike was when hot more difficult to start (2-3 puffs then kick back, had to pull open the throttle to kickstart it) and also more smoke and increased fuel consumption..

Googled what can be the cause of a failing injector, but no things i can relate to.
I mounted a fuel filter and the engine has run about 28.000 km's.
The only thing i can think of is carbon deposits

I will get the bike back tomorrow Will take it apart and post pics

I almost bends my mind from the again failing front drum brake...
(if there's here someone who built in a other brand drum and brake plate, i would be interested)

More info tomorrow..

[the grinch]

hi,

I put a yamaha wheel in some suzuki forks.I had to make a plate that held the drum on the forks. It was straight forward i just had to make a spacer. the spindle went through the plate and i made it fit the new wheel and attach to the original lugg.

alex

[Diesel Dave]

It’s most likely that the piston has cracked at the bottom of the combustion chamber. It happened to mine.

The new replacements have a more robust firm.

Do you still want my old drum brake?

[arnaud]

hey dave, nice to meet you agai\n..doies yoru drum braske work really?
first ik ahve to getout of this problem..
what can be the cause of these injector malfunctions?

[Diesel Dave]

I don’t think it’s the injector, I think the piston has cracked.

The brake is as best I could make it but you really need better handlebar levers.

[arnaud]

Just as i suspected, because of the smoke before and curious starting behaviour; broken piston.
Cause would be a failing injector, but does anyone know what could cause this?
This 13 HP Wuinsun has not run even 30.000km or so..

[Diesel Dave]

I still don't think there is anything wrong with the injector, unless you have been playing with the timing.

Most need retarding from standard and not advancing (pump fuel has a higher cetane rating than the crap they were designed for. This has a fast ignition time so tends to cause hard knocking at idle.

[arnaud]

Well, i think i will have the injector tested. Also i checked if the TDC mark on the flywheel corresponds with reality, it does.
Timing is as in manual..spot on.

[arnaud]

..yesterday on my way back from Hamm..
trundling along at 85-90km/h (top speed 100kph says navi device)
Sudden loss of power, strange noise, a LOT of blue smoke..
No compression anymore
My first guess is a pissing injector and so piston damage.
The same day, the bike was when hot more difficult to start (2-3 puffs then kick back, had to pull open the throttle to kickstart it) and also more smoke and increased fuel consumption..

Googled what can be the cause of a failing injector, but no things i can relate to.
I mounted a fuel filter and the engine has run about 28.000 km's.
The only thing i can think of is carbon deposits

I will get the bike back tomorrow Will take it apart and post pics

I almost bends my mind from the again failing front drum brake...
(if there's here someone who built in a other brand drum and brake plate, i would be interested)

More info tomorrow..

[arnaud]

Update; Injector works fine?
So maybe faulty fuel pump?
Clues; More smoke and difficult warm start (had to open throttle more open to get it running, or else a few puffs and stall)

[arnaud]

Well, pulled the engine further apart, the camshaft seemed allright, no visible excessive wear, i understand how a plunger fuel pump works but.. what could be wrong with it?

The injector nozzle is fine and works as it should.
Symptoms short before the piston busted;
-Bad warm starting
-A lot of smoke,

[Diesel Dave]

The piston cracks long before it fails completely and the crack acts as a one way valve letting oil pass from the crankcase and sealing under compression.

Stop looking for faults, install a new piston and it will run fine.

[arnaud]

Okay but.. the previous symptoms cannot be explained by this? Or maybe a very small rupture in the piston? i cannot imagine...
so the failure is just China-bad luck you think?

[Diesel Dave]

Yes, replacement piston may be slightly different (and don’t rev it over 4000, or they fail quickly.

My replacement has lasted the gruelling summer tour, completing both the Grossglockner and Stelvio passes.