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Motorbike twin starter motor
RichardK - 19/2/12 at 12:44 PM

I've posted this on another forum but you guys and gals seems to know everything so here goes:

I've got 2 starters and they are both the same in that when I connect either one up directly to my car battery you can stop the motor with your fingers (with the help of a towel !) surely this isnt right?

I have aquired a ex250-c1 (gpz250) which as far as I can make out is identical to the 305 belt drive (except the bores obviously) and the motor that was in the frame had been bodged beyond the extreme, which caused the engine to be seized when I got it although the seller said it was free anyway could the previous owners attemps to start a seized engine damage the windings? Havent got a meter accross the windings yet as I just want it confirming that the motor should have loads more torque that both of these have.

Cheers

Rich

Then later I've posted.....

Just checked all of the communicator segments and they are all clear and all give very low resistance, cleaned up the communicator with emery paper and still the same, I'm going straight from a car battery with jump leads to the motor and I can still stop it with my fingers but if I let it spin its seems to sound nice and smooth, just no torque. Both starters are the same although haven't cleaned up the other one.

Any ideas?

Cheers

Rich

RichardK - 19/2/12 at 12:45 PM

It's a kawasaki gpz250 twin btw

Love

Rich

MakeEverything - 19/2/12 at 01:44 PM

Is there a gearbox on the engine that the starter drives? I would have your that a twin needed quite a bit of torque. Can you turn the engine over by hand? It might be proportionate and enough to turn the engine, thoug I would be surprised.

RichardK - 19/2/12 at 01:48 PM

Nah no gear box is essentialy got a clutched gear on the back of the stator,, yes can turn it over by hand although is hard due to the compression but it will turn, annoyingly there is no nut to put a socket onto to turn it over.

Cheers

Rich

Slimy38 - 19/2/12 at 02:32 PM

I don't know about this particular engine, but on my Yamaha 600 (inline 4) the starter motor is tiny and there are two reduction gears before it gets to the crankshaft, with something like 5:1, 5:1 and 10:1 ratios. One of the gears is clutched.

Chippy - 19/2/12 at 04:46 PM

quote:
Originally posted by RichardK
It's a kawasaki gpz250 twin btw
Rich


Send a U2U to robocog, he has one, although I think his is a 500. But sure he will be able to help as well into the GPZ. HTH Ray

RichardK - 20/2/12 at 01:17 PM

Friggin cheapo jump start cables,I'm going to say no more.

Cheers

Love

Rich