Faulty Starter Motor on H Model

[Guest]

Morning!

Just changed the battery on my H model 400 and despite a brand new fully charged battery, it still behaves as if the battery is flat. Will turn over for a second or so and then dies. Also changed the Starter Motor relay and checked the cables for a dodgy earth but they seem to be fine.

Does this mean My starter motor has packed up?? If so is there any way of testing it apart from swapping it for another one that you know works?.

Chris.

[Jamz]

Hmmm... sounds like you've got a short somewhere, but there's loads more you'll have to tell us on this one...

When you say it turns over for a second then dies, do you mean the battery has gone flat after a few seconds trying to start it??? Have you checked the battery's power on a meter before and after trying to start it??? Are you using a battery charger between attempts to start it???

A good way to test if your starter motor is working properly is to put a screw driver across the 2 nuts on the bottom of the starter relay/solenoid with the ignition on. This will spark like a giraffe and will instantly turn your starter motor (no need to hit the starter switch).

I've just had similar problems which took me ages to sort out, and many replaced parts, but in the end i found exactly what it was and some other useful tips along the way!!!

[Guest]

Tested the battery both before and after trying to start the bike and i'm confident the battery is supplying enough charge. Have also tried running jump leads from a car 12v, connecting the negative jump lead straight to the earth point on the bikes crankcase and the other to the positive terminal on the bike (battery side and not switch side) but it behaves in exactly the same way, turns over slowly for about a second before just stopping altogether, it really is like the batterys flat..

I've even tried turning the bike over by hand in third gear just to make sure then engine isn't tight but it's fine - I can actually start the bike up by pushing it and selecting third gear..

My next attempt is to run jump leads straight from the battery with the negative straight on to the earth point on the crankcase and the positive straight on to the starter motor. This way i've eliminated the starter switch, the magnetic solonoid switch and even the postive and earth cables. If it turns over fine then I know the problem is elsewhere.

So what ended up being the problem with your bike? - please tell us it was cheap and easy to fix!!?

[Jamz]

Why are you connecting the car battery to the earth point on the bike and not to the negative battery terminal on the bike???

Did you try shorting the 2 solenoid connections with a screwdriver? What happened?

My bike simply didn't have enough power to start it (or even to sound the horn), and it was due to a break somewhere in the live (white on L models) wire somewhere in the loom!!! Sounds an easy fix, but i spent hours and hours trying to find the break and bypassing parts of the loom etc....

[Guest]

I was planning to run the jump lead straight to the earth point on the crank case to eliminate any of the leads on the bike. If it runs ok then I can try jumping it from the negative terminal on the bike and then work my way backwards from there..

Haven't tried the screwdriver across the terminals yet, sadly the bike doesn't live where i do so i'm going to try and sort it over the weekend and will go from there.

Prey to god it's not a problem in the wiring loom, can be a real pig to start tracing faults in that lot. Do you know where that white lead starts and finishes on your bike? May use that as a starting point if the above attempts fail.

Thanks for your advice so far matey..

[SimonH]

Like jamz said, you can turn the starter motor by connecting the two solenoid screws together with a screw driver, but don't hold in there too long or it'll weld itself to the screws!

[Jamz]

Yeah, a couple of seconds will tell you if it's working or not - it's usually one of those moments where you think " Yay!!! That bit's DEFINATELY ok then!!!!"

The live wire (I just checked the manual) seems to follow the same route on the H model as on the L model, so it runs from the ignition switch then splits into 3 further down the loom and feeds the regulator/recitfier, junction box, and the starter solenoid/battery.

It's a really tough call whether the problem lies here unless you have all the right testing equipment - i replaced the solenoid, junction/fuse box, regulator/recifier, and was gonna change the CDI unit aswell, and i don't think i needed to change ANY, if i'd been able to find that fault in the wire!!!

Good luck - let us know how you gat on!!!

[Guest]

Wey Hey! - it worked! - new starter motor in place and it started first time. So a lesson learned, if your bike is behaving as if the battery is flat when trying to start the bike, but your healdights are at full brightness (suggesting a fully charged battery) then there's a good chance the motor is dead. Strange as I took the old motor apart and nothing seemed out of place, just old brushes causing arching I spose..

Only last niggling problem left to solve is that once the bike was back together the throttle appeared to be locked at tickover even if the throttle was fully open. Butterflys are opening fully and the cables are all in tact and well lubed, only thing that seemed to make a difference was taking the airbox off which then cured the problem. Going to take it out and give it a good thrashing tomorrow night and see if that solved the problem as it's been standing for nearly 5 months now.

If not then you know i'll have to start another thread!!!

[Jamz]

If you think it might be fueling i'd recommend buying a bottle of STP Fuel System Cleaner - costs about £12 from Halfords, but it's well worth it!!!

Stick about half of it in and see if that does anything. Either way it'll run like it's on Nitrous for that tankload!!!

Also a capfull in each tank will stop carb icing.

[gubbs]

Ahh this old thread rather accurately describes my current problem.

Only thing is, mine only does this when its hot ..