daveyson wrote:With your direct battery test, if you connect earth to the starter motor body,  instead of the frame, it might then crank normally and even start.

OK your battery is good for 12.8 Volts, but the plates in the battery might be all clagged up, with the result that only a small amount of Amps can get pumped through. You need to get it load tested to be sure.

Tested already direct wiring, (including ground) from battery to starter motor. With no load spins like a wonder but fails when inserted (or cranks only without sparks ecc..)

Battery used normaly cranks a 2.0 lt diesel (both battery and car have less than 2 years). Battery is around 80 Amps.....even if I lose 70 % of it, still remains enough for the K75.
:-(

I may try to remove battery from the car and use shorter cables.

Did you try to lever a piece of timber against the starter to see if it's strong?

Propper connectors might work better than jumper leads.

daveyson wrote:Did you try to lever a piece of timber against the starter to see if it's strong?

I tried to hold it with a piece of linen by my hand. I can keep it stopped if wanted, but when spins it has power that actually seems should be enough to crank the engine. At the same time engine can be turned by hand through rear wheel in 5th gear or by clutch now (gearbox dismantled).    My main problem is that I can not tell if starter motor is too week or torque required to turn the engine is too much.(?) So I do not know where to investigate deeper.

I think your starter is weak. It should not stop with cloth. I wouldn't use cloth it might bind and pull your hand in.

It should chew linen and wood to pieces without stopping. I've only done this on starters for cars, so I'm not sure about motorcycle starters, but to me it seems like your starter is weak.

daveyson wrote:I think your starter is weak. It should not stop with cloth. I wouldn't use cloth it might bind and pull your hand in.

It should chew linen and wood to pieces without stopping. I've only done this on starters for cars, so I'm not sure about motorcycle starters, but to me it seems like your starter is weak.

Yes, I think I will get it tested in some electric shop somehow.   The point is that I've already bought 2 more used but guaranteed starters from a German bike shop, and all 3 gives the same result.

Hopefully you get lucky with battery cables instead of jumper leads. Hopefully you get some more feedback about the starter. Running out of places to look other than the engine.

While cranking it drops to five Volts. Can a good battery read that low? I wouldn't run the car for your tests. I'd get a load test on the battery.

Stopping it with your hands and cloth sounds even weaker than the timber test cause you haven't got any benefit of leverage.

Doh, I'm just thinking there's no clutch in a bricks starter, so maybe your test points again to not enough Amps.

How are you doing your Amp tests?

Will your car start through your jumper leads?

daveyson wrote:Doh, I'm just thinking there's no clutch in a bricks starter, so maybe your test points again to not enough Amps.

How are you doing your Amp tests?

Will your car start through your jumper leads?

I use the tester to give current to starter motor positive conection from battery. Or I use tester to shortcut 30 and 87 pins of the starter relay.                I will test jumper cables but already used 2.   And starter spins well when not inserted in bike.

Suppose the battery was outside your car. Can you start your car using your jumper leads?

daveyson wrote:Suppose the battery was outside your car. Can you start your car using your jumper leads?

Battery is installed in the car and car was started (engine running for charging) during testing.

Try it though. If you can't start your car using your jumper leads, then the leads are not good enough.

daveyson wrote:Try it though. If you can't start your car using your jumper leads, then the leads are not good enough.

OK I will... even if tried with 2 pairs and I use jumper leads made exactly for purpose of batteries emergency connection.   An other issue I noticed: when using bike's wiring (so I connect the battery to bike, not direct wiring to starter), RPM indicator goes up (to 2-3000) for a second at ignition (when I push starter button).