JH600 stalling

[998S]

In conversations with Jialing (CQ), it hinted that it thinks one of the problems (related to stalling) may be related to dirt/dust getting the various electrical connections and/or sensors.

Barry, you want the sad truth? It is because they don't know, don't want to know, or not have the capacity to know ...

I can tell you that, as long they don't gave a solid reply, from which you get the impression that they understand the problem, and give logical solutions and alternatives, I should NOT even bother to bring the bike to them. All they will do is start changing the tire valve caps, and tell you it is the solution, sadly no kidding ....

Again, I might be wrong in the lean running accessment, but as long as no one can convince me of any other cause (and I have not read or seen anything coming close) I keep convinced that it at least contributes to the problem.

[ZMC888]

998S Do you think that Jialing might have an 'Asian' fork spring and a thicker 'export' fork spring?

All they will do is start changing the tire valve caps, and tell you it is the solution, sadly no kidding ....

This all depends, TIC so guy dealing with you may just have a well connected daddy, and no clue. Or you might get an engineer who worked on the original project knows what he is doing, is an open-minded problem solver who isn't an arrogant dick. Highly unlikely, but not impossible!

[Barry]

Can't remember if anyone brought up the Laser aftermarket exhaust here, that LJH and others have installed on their JH600. Can this be a factor for the stalling issue, or at least contribute to it? I'm still running the original exhaust and so is LJH's JH600B as far as I know!

[998S]

No. I don't think so, too much trouble in double parts.
I understand the only difference is the connection of the rear shock to the bracket.
I understood it has 2 options (holes), which will alter the ride height.
If the front fork length is different though, they went the professional way.

Eric

PS. Increasing the ride height on the back will rotate the whole bike forward.
This decreases the fork angle, resulting in a quicker turning / less stability.
In small amounts this can be desirable, do it too much and a severe head shake is waiting for you.
That's why they should use longer forks for the export versions as well.

[bigdamo]

Dear Eric,

Thanks for this guidance. I've read and re-read Pfaelzer's discussion of the JH600 fork, its diveyness and his upgrade to progressive springs and different fork oils, but I find myself still intimidated by the whole thing. This should be a good winter project, since my forks have never been serviced. At this point I'm not even sure whether the diveyness that I'm currently experiencing is the way the bike is supposed to behave or if there is a problem (insufficient oil, wrong viscosity, bad spring(s), etc). I only have one other bike (my KLR650) with which to compare, and I can say the JH600 front end is much softer/mushier, and I don't like it at all.

I don't want to hijack this thread, but I am curious about how to proceed. How could I get an independent assessment of the current fork dive and whether it's normal or abnormal? What would be the next steps -- just tinker with different viscosities of fork oil, or go for progressive springs and then start tinkering with oil?

thanks for any and all guidance!

cheers

I thought the KLR 650 had to soft a springs on it.

If you don't know about setting up suspension I would take it to a dedicated suspension tuner if there is one in China.I find servicing and setting up suspension more complicated than rebuilding an engine(Getting all the settings hi speed, low speed, compression, rebound etc right for me is the hardest part)I have taken months to do this .

Now I just take the bike to a suspension guru(back in Australia) he watches me ride the bike and we go from there.He checks my suspension sag first.

Luckily or unluckily most Chinese motorcycle suspension is basic at best.

Start with the springs if you can find the suspension sag details for the JH600 that is a start.

Then you start with oil weights and volume or a revalve.

There are plenty of forum and websites on how to set up suspension out there.Far to complicated and in depth to add to here.

If you are riding with a lot of weight saddle bags etc I doubt that Jialing factored that in for the suspension set up for the bike.

[998S]

As mentioned before, after market exhaust generally cause a leaner mixture, as they are more "open".
Increased back-fire is the result of that, mentioned by several of you.

We compensate for that by adding fuel to the map in certain areas, but you might need to take some fuel away in other parts of the map.
Professional after market suppliers often even supply a model specific ECU chip with a modified map on it, to compensate and increase power in stead of only 'feeling due to the increased noise'.

But for your problems: Milton's bike has a standard exhaust, has lots of stalling problems (both kinds), and read even a lower CO then Motokai's bike.
Not the main reason for the stalling IMO.

E.

[euphonius]

Can't remember if anyone brought up the Laser aftermarket exhaust here, that LJH and others have installed on their JH600. Can this be a factor for the stalling issue, or at least contribute to it? I'm still running the original exhaust and so is LJH's JH600B as far as I know!

Barry, interesting question about the Laser. I was wondering about this when Eric mentioned a gas mix sensor in the exhaust system. When I had Mister Muffler Man saw off my stock muffler, there was no sensor anywhere there. Motokai and I have Lasers, but Milton does not. Milton had epic stalling problems. I have not, though I am not immune. Motokai has had good patches and bad.

In any case, I would not want Jialing to get in a lather about the Laser. The problem exists regardless of which muffler is used.

Perhaps we can add this information to the data we all supply to Motokai.

cheers!

[Barry]

Furthermore, I don't think any of you had stalling problems directly after installing the Laser.

How are the stalling issues if you compare the earlier JH600's vs the newer version? Euphonius' and mine are earlier version than Motokai's, Milton's and LJH's if I'm correct!

[ZMC888]

I know people are going on the 'bike is too lean tangent' which is highly logical and plausible. But shouldn't EFI systems be able to adjust for it? Also shouldn't a Bosch EFI system work as well if not better than the industry standard, and shouldn't it be easy to achieve with a 600 single, being a fairly simple and well known design?

This is only a theory, but maybe this could be an electronics issue and the spark is too weak? We all know Chinese shops don't adequately trickle charge new batteries overnight, we know that a company like Jialing might have mediocre wiring and that the ignition coil and leads might also be causing the problem. Just a theory to eliminate.

[998S]

Eric mentioned a gas mix sensor in the exhaust system

If I remember well, the CO sensor is mounted on the right side, halfway the tank, in a sleeve on the exhaust-header.
That is why it was not removed when they changed your silencer.
It still should work.

I know people are going on the 'bike is too lean tangent' which is highly logical and plausible. But shouldn't EFI systems be able to adjust for it? Also shouldn't a Bosch EFI system work as well if not better than the industry standard, and shouldn't it be easy to achieve with a 600 single, being a fairly simple and well known design?

You are right that the sensor measures the CO in the exhaust gasses, then adjusts. This is however a slow process with a long delay, not taking place all the time (I will not bother you with open and closed loop modes though), and within limits.
Besides, that only 'lifts' or 'lowers' the total fuel map.
The problem remains that the map itself is set very lean to pass the emmission approvals.

This is only a theory, but maybe this could be an electronics issue and the spark is too weak?

I am quite sure you have point here.
I am sure most components are of limited quality, such as the decompression valve system, surely the electronics, and most likely other components.
A weak spark should specifically result into poor starting, and a rough idle.
You might have that problem, as I read that most of you run the bikes at rather high idle.
It is IMO not a reason for the 'cut-out' though.


Eric