JH600 stalling

[Lao Jia Hou]

Interesting article re Fuel Injection ...

http://www.chinamotorworld.com/viewnews.asp?id=2016

I was surprised to hear that Walbro has a plant in Tianjin. I might need a new Walbro fuel pump for another FI bike I own. It is $500 at a USA bike dealer, yet only $140 through Progressive (also in the USA). Hmmm, maybe even less just down the road from me at Walbro.

Dear Mr Walbro ... any interest in manufacturing after-market FI systems for the JH600?

[998S]

Funny, but Jialing is mentioned as their customer ... :)

[milton]

I think it is ice cream time finally!

I've just completed a trip about 30km in distance around Shanghai, from Minhang 闵行 to Pudong, but purposedly by way of Nanjing Lu 南京路 in order to produce lots of stop and go situations. I am happy to report there wasn't a single stall during the whole trip. This is the second time I had the bike on the road after Eric's putting in the adjustment to the idle screw. The first ride on Friday was also 100% stall-free, but in shorter distance (about 15km).

1. This feat was accomplished after applying Eric's "magic touch" made to the TPS and subsequently resetting the "idle screw" to its original factory setting (close enough, since we don't know any more after blindly fooling around with the screw a while ago). Before turning down the idle screw, the bike was ridable but still stalled off and on, with gas mileage increased at least 12%. It is not yet known the feul efficiency for this latest setup.
2. Originally this bike was in very poor condition, stalling 10, 20 times even in a short 15km commute to work. It was nearly unridable before I first sent it to Eric.
3. The idle rpm in neutral was around 1750 when I first got it on the road, gradually dropped to 1600-1650 after 20km or so and remained stable.
4. The ride was nice and even enjoyable again. The only thing was that I needed to rev up more before upshifting the gear. This perhaps is why Eric calls the fix "temporary", as it is basically "fooling" the ECU in some way so we can get higher fuel mixture into the engine, which is Eric's theory all along.
5. Did not notice anything unusual in higher rpm bands.

Lesson learned: We (Eric) had a theory about the stalling, we made the measurement (CO level is so much lower on Jialing than almost all other bikes), we did a proof of concept (by blocking partially the air intake to increase the fuel mixture), we invented a magic mod to the bike consistent with our theory, and we changed one thing at a time so we don't lose track of where we are. The result: ice cream time.

Congratulations, Eric!

I'll do more riding under various conditions and keep you guys posted.
Then the next step is to work with Jialing for a permanent fix. Don't laugh. If we play our cards right, it may just happen.

[998S]

Yes yes yes ..... Milton, you'r my hero today.
Ohhh man, this is soooooo sweet ...... We beat them allllll ......

[marcomagica]

That's just impressive guys!

Though I don't know Eric, I assume he's just a motorbike enthusiast who love motorbikes. Yet you managed to pull out a solution that so far is proving right. Well done!

Now, if only Jialing loved their bikes as much as their clients do instead to stick their heads in the sand!

Congrats guys, keep up the good work!

[998S]

Remember this one from a month ago?

I had not one, but two Jialings here this morning ... not only looking almost the same, but also stalling the same ... Motokai showed up together with Milton.
<>
From what I found, I can make the following preliminary conclusions:

1. Stalling after start:
My impression is, that the ECU has a "enriching" program which replaces the choke on a carbureted bike.
To me, I think this program is not related to the actual input from sensors, but is just enriching the mixture for the first e.g. 500 turns.
This because you can almost set a clock on the timing it will stall.
So it means the engine runs the first e.g. 500 turns on an enriched mixture, then the ECU shuts it off, going back to the lean mixture, which is too much of a change and the engine stalls, hot or cold.

2. Stalling at a stop:
This is indeed exact like Ducati's 'too lean' stall, unpredictable, always while coming (almost) to a stop, and being able to just restart and idle fine afterwards.
For this one I am sure that it is caused by the lean running, and can be solved by a richer mixture.
I did a test of the CO percentage in the exhaust gas, and it shows that the CO percentage is less then half (!) then I think it should be, on both bikes!
<>
On a side note: I don't think that it is a hardware problem in itself.
The bikes run ok, don't make strange noises, don't hiccup, rev up fine, feel smooth, nothing strange.
I can imagine that Jialing is improving their design (never wrong), but in the basic concept these bikes should not stall in the version they are!
They should also run much lower at idle then they do right now.

If only Jialing had come to these conclusions a year ago .....

[milton]

By diligent effort LZD has received a response from Jialing today. Sometimes in next week Jialing will send 2 engineers to Shanghai to look at our sick bikes and listen to our story about our "home grown" fixes (Eric's). This is the first step to make our problems "official", which requires a formal report drafted in response to our complaints. That report, once officially submitted, will then wander through the Jialing organization for a collective resolution. Those 2 engineers are in the process of booking the flight for Shanghai.

LZD will be receiving them when they land at Shanghai and take them to Xiao Fan's to check up Motokai's poor bike. After that first stop, LZD would like them to meet up with Eric and listen to what he has done to my bike. They will probably allocate 2 days for us.

This is a great progress made by LZD and our persistent effort of getting to the bottom of this thing. I will let you guys know more as soon as I have the exact dates from LZD.

Cheers!

[998S]

Well, that seems at least a first big step forward, congrat so far!
If you let me know asap on a date and time, I will come to the shop.

One advise: I should NOT disclose the home grown secret yet, just the "problem, analyses, conclusion, solution" thing.
Let them by their own come to conclusions, otherwise you will all end up with a temporary solution.
People have said too much already ;)

E.

[Barry]

Any news? Any Jialing engineer set foot in SH yet, or the planes in Chongqing have stalling issues too?

[euphonius]

Any news? Any Jialing engineer set foot in SH yet, or the planes in Chongqing have stalling issues too?

Dear Barry, thanks for asking. Latest word is that Jialing engineers will descend on a lovely Dutch-accented private garage in Hongqiao tomorrow morning, and at least two spluttering or recently spluttering JH600s will come under inspection. May they splutter and splutter for all they are worth with the engineers present!

My currently unspluttering dog ain't in this fight, but I've offered to have it present too, as a "control" that shows how identical bikes can behave in different ways, thus proving that annual EFI tuning, and also spot tuning, will have to become integrated into Jialing's customer service offerings.

cheers!