JH600 stalling

**milton** · 03-27-2012, 04:49 AM

Originally Posted by MotoKai

Just heard from euphonius who dropped my ecu off with mechanic Xiao Bao that my JH600 didn't react to the new ECU.
Consensus is that it's bad fuel pump or "suspect wiring."

Have you had your fuel pump relay checked?

**998S** · 03-27-2012, 05:25 AM

Originally Posted by milton

Have you had your fuel pump relay checked?

Or the main circuit breaker?
Sounds very very weird ... Milton, I am afraid I was right ;)

**998S** · 03-27-2012, 05:27 AM

Originally Posted by euphonius

Anyone have any idea where to get one of these "caps" in Shanghai? Shouldn't any decent repair station have one?

You can just use it from the old plug, and screw it on the new one.
Or you buy a 10 quai plug with the cap on it, and take it from there.
Any big motorbike shop should have them, they pretty common on big bikes.

**euphonius** · 03-27-2012, 05:30 AM

Good advice on the little screw-on caps/tips for the spark plug, 998S. Motokai did try to spin the one off the Denso, but he said it wouldn't budge without damaging the core.

As for the fuel pump theory, I listened as Bao turned over the engine with the two ECUs (MKs and mine) and it was the same: total absence of the fuel pump spin-up sound that should happen when you switch on the ignition key, before you thumb the starter. So it's pretty clear that pressurized fuel is not being delivered to the injector, due either to a bad pump or bad electrical control of the pump. But I think we can rule out a bad ECU signal to the fuel pump.

cheers

**TB-Racing** · 03-27-2012, 05:38 AM

Originally Posted by euphonius

Good advice on the little screw-on caps/tips for the spark plug, 998S. Motokai did try to spin the one off the Denso, but he said it wouldn't budge without damaging the core.

G'Day,

Have a few NGK LB05F Motorcycle Spark Plug Caps sitting in the tool box for the Z50 Honda Monkey bikes, no need for the screw -on top if it helps, ready for pick-up.
http://www.brandedbiker.co.uk/NGK-Mo...Cap-Black-5063

**Barry** · 03-28-2012, 03:11 AM

Any news Motokai, did you manage to locate the exact cause of the current issue yet?

Don't worry about us getting bored, reading JH600 related news! I think most of us would like to know as much as possible about upgrades and how to solve issues. So we can solve/locate issues faster in the future, in case we run into them. It's a learning process for all of us.

Sure I would like to be out riding now, but will you tell my boss? At least reading anything JH600 related keeps us less bored during working hours.

Cheers,
Barry

**998S** · 03-28-2012, 03:40 AM

Originally Posted by Barry

but will you tell my boss? At least reading anything JH600 related keeps us less bored during working hours

****BLIEP --- THIS MESSAGE IS AUTOMATICALLY FORWARDED TO THE BOSS --- BLIEP****

**MotoKai** · 03-28-2012, 04:28 AM

Originally Posted by Barry

Any news Motokai, did you manage to locate the exact cause of the current issue yet?

Trucked the bike over to the Honggu Lu Mechanic Fan's place. He has a "JH600 Lab" setup up there now, due to a couple of JH600Bs (sidecars) that have been scrapped and now serve as spare parts which can be used to compare against parts on my bike. This allows Fan to use these extra parts as a REAL 3D TACTILE BLOWN-UP JH600 MANUAL and TEST LABORATORY (of course he's using the actual paper manual too).

So, last night Fan sussed out that it's most likely one bad wire coming from the Fuel Pump Relay (Good on you Milton!). So now he has the ECU harness out from another bike and he's working thru to find the source of the issue and which wire. Hopefully today I'll hear more.

BTW, another JH600 rider gave me an extra Fuel Pump Relay plug last Summer saying it's good to carry one with me.
I think I should have a trailer to haul all the parts I "should carry with me" when riding.

For reference, see below diagram indicating the Fuel Pump Relay:

fuel pump relay.JPG

**milton** · 03-28-2012, 05:42 AM

Originally Posted by MotoKai

So, last night Fan sussed out that it's most likely one bad wire coming from the Fuel Pump Relay (Good on you Milton!). So now he has the ECU harness out from another bike and he's working thru to find the source of the issue and which wire. Hopefully today I'll hear more.

The "spare" relay you have probably came from Xiao Zhang, the author of the following post:
http://bbs.750.com.cn/showtopic-6000.aspx

According to him, the blue Tyco relay is a "better" one, which has a bit different wire leads. How was that judged as better is beyond me.
This may be of interest to those who may one day need to replace his relay.

**Barry** · 03-28-2012, 05:51 AM

Originally Posted by milton

According to him, the blue Tyco relay is a "better" one, which has a bit different wire leads. How was that judged as better is beyond me.
This may be of interest to those who may one day need to replace his relay.

Pins are different, so you can't just replace it!
Why not a Bosch relay then? Matches the ECU