JH600 stalling

[fons]

yeah man, mono-cylinder should never die

Hi Fons.
From everything I have read on this forum, plus what I have tried on one of the bikes, I guess 40% is a incorrect setting of some parameters at the factory, 40% is within the ECU (lean fuel map / spark / error / whatever), and the rest is the vurnability of the total system (decompression valve, bad fuel, dirty fuel filter, bad sparkplug, bad batttery, etc.

It is good to know that you don't have problems, which only confirms my very first saying that such a simple design like a 1-cylinder engine should basically always run as long as it get enough fuel....
I am not sure how succesfull we will be in the next step towards Jialing, but it is good to know you got a problem free bike.
I might call upon you in a later stage.



Milton, the weather is getting warmer by the end of the week. Try to keep track of the air-pressure & -temperature against the stalling.
If you want to make a better base, pass by my place on your way home for 5 min, and I turn the setting screw back, that should give you a stable idle for the rest of the week.

E.

[fons]

actually this bike let me remember my 1995 Range Rover classic. it never fails me on the terrain except i rolled it over in the Sahara desert. But it turn me down so many times on the street. always some small problems, like gasket, screw, etc. but if i buy a 4x4 again, it will be still a Landy.
This time, i'm still lucky with my jh600A. it clocks 8800K on the meter. i have no mechanic problem even with factory must be replaced battery.
we had some funny stalling, but soon we realized because we overfilled the tank.
one thing must to say, the factory panniers are sucks. cosmetic stuff. i will replace them until they are 50% broken. they are at 20% status now.

[998S]

Does this means that if I'm ever going to ride to Tibet, my bike (YBR250) will adjust automatically to the new altitude (lesser pressure I suppose) and oxygen concentration?

Yup, As Milton's observation of the caburated bikes confirms. This is a big advantage of fuel injection.

According to Eric, our JH600 might actually enjoy the high altitude better, as the fuel mixture is raised up due to the lower pressure.

Well, to say it even more correct, the fuel decreases under lower pressure.
But I guess it lowered less then it should, leaving you with a slightly richer mixture then in SH.
It furhter confirms again that the main problem is fuel related.

[MotoKai]

What "air-pressure"? You lost me there.

Hey Milton - I'm a visual learner. I needed to do some homework after the morning at Eric's with you, Jeff and LZD.
Here's what I found (Honda has great diagrams and explanations of how things work), which ties together the workings of many things discussed here:

An image of a conventional FI system for motorcycles:


Cut model of FI:

[slabo]

I've been following this thread from day1 looking forward for a satisfactory ending. If I were in LJH's shoes, I would also sell the bike. Troubleshooting an ECU is not something an end user should be doing when the manufacturing company is still in business and selling the same bikes. Apparently it's a black box for JL more so than the riders. Which confirms what most expats think about Chinese manufactures: they're just copycats, but do the job badly. It's really sad because the JH600 seemed the only decent do-it all bike in China. And now with C3 seems there are no decent bikes to buy legally in China. Shame really..

[998S]

Honda has great diagrams and explanations of how things work

Well, technically pretty much as I told you right ...

During lunch time, and after the discussion on the barometric conditions, I was trying to think the Chinese way, and why they proposed to disconnect some sensors. I guess they proposed to disconnect the barometric sensor.

If we do so, I think the ECU will go into recovery mode for the signal, and falls back into a pre-set value.
If this pre-set value is higher then the actual pressure (which might be so for safety reasons - lean mixture is much more dangerous for an engine then a rich one), the ECU will add more fuel to the mixture.
This might stop the stalling.

Might be something we can further try.
It will lift the map a bit furhter up, and it might allow me to tune the throttle override a bit back, reducing the negative aspects of it.

Of course this might only work at sea level, drive to Sichuan and your bike will be flooded like an old caburator bike.

[998S]

Lao Jia Hou + Milton,

your postboxes are full ... cant reach you with copy of a PM...

[euphonius]

Lao Jia Hou + Milton,

your postboxes are full ... cant reach you with copy of a PM...

Ditto Motokai's.

[fons]

hey fella,
you better not ride a made-in-china bike on the chinese road. so you can avoid all these problems.

Euph, yes your bike was indeed faultless during torrential rain.

Could be a bad batch of leads, coils, EFI, sensor reading wrong, could be EFI itself, a question for a real engineer. Needs a BMW or Bosch engineer from Germany or Austria, I'm sure they'd find the problem in five minutes with the correct apparatus.

If it was my bike I'd try:

1. Make sure I had a Japanese manufactured NGK spark plug of the correct rating and gap measurement.
2. Buy a new internationally known brand battery and long charged it properly before I used it.
3. Change the lead to an NGK.
4. Try running Shell 97 octane.
5. Try changing the fuel filter if possible.
6. Try chevron techron fuel system cleaner or BG 44K
7. Try rewiring electrical system better
8. Try an aftermarket air filter and muffler to see if increased air flow actually helps.

after that I'm stumped, and would clearly be a Jialing company issue.

[fons]

Hi Eric,
maybe you could check up my 600A which is built in may 2011. latest ECU. Most important, never stall.
Then you can compare this one with Milton's. I don't know if it helps.

Well, technically pretty much as I told you right ...

During lunch time, and after the discussion on the barometric conditions, I was trying to think the Chinese way, and why they proposed to disconnect some sensors. I guess they proposed to disconnect the barometric sensor.

If we do so, I think the ECU will go into recovery mode for the signal, and falls back into a pre-set value.
If this pre-set value is higher then the actual pressure (which might be so for safety reasons - lean mixture is much more dangerous for an engine then a rich one), the ECU will add more fuel to the mixture.
This might stop the stalling.

Might be something we can further try.
It will lift the map a bit furhter up, and it might allow me to tune the throttle override a bit back, reducing the negative aspects of it.

Of course this might only work at sea level, drive to Sichuan and your bike will be flooded like an old caburator bike.