GT550 Alternator Rotor Thread

[pfg49]

This is my alternator rotor. As you can see the bolt that holds it on has been butchered. I'm not sure the bolt is the right thread, can anyone tell me what the thread size should be please?

[GTandcbr]

The standard bolt is M8 1.25 pitch.

[pfg49]

Is that the standard bolt with captive washers?

[GTandcbr]

What model 550?

J/K part number 31720-33020 bolt and captive washers

L to B part number 01122-08658 just the bolt

Just looked on Reiners list the top one is for the kokusan generator he has them in stock so presume the lower one is for Nippon Denso?

[Alan H]

You need a tap to clean the threads in the crankshaft too, looking at the threads on the bolt.

[pfg49]

Thank you all for your help.

Alan,

You are right, that's why I wanted to know the thread size.

The reason I've removed the stator, is because I can't seem to fathom out why the bl***y thing won't charge. Am I right in thinking I should have 12v at the green wire that goes to the brushes with the ignition on?

[Alan H]

Yes. That comes from the regulator. Disconnect it first before testing.
If the rotor is to earth you might not get a voltage otherwise.
I' ll try and find a thread I did on this very subject and post a link.

http://www.kettleclinic.co.uk/kcforum/v ... g&start=30" onclick="window.open(this.href);return false;

and

http://www.kettleclinic.co.uk/kcforum/v ... t=charging" onclick="window.open(this.href);return false;


Lots of good info on there. Read it carefully though and if you need new rotor carbon brushes, don't get genuine, buy some that are a bit too big at about £2.99 a pair and emery them down a bit like I did.

By the way. I'll be in the Exeter region next week with the caravan, so not a million miles away from you.

[pfg49]

Does anyone have a Parts Manual diagram of the Kokosan alternator they could post, showing the parts where the green wire terminal attaches to the stator cover please?

[Drewski]

Any use? :-



Google Images or searching through eBay are great places to get reference photos, as long as your certain that what you're looking at is what it claims to be that is!

BTW, is that rotor on a key......or just on the taper? If the thread has gone, and there's no key, won't it be spinning on the crank?

[yeadon_m]

The rotors are held on only by the taper. The taper hold can be broken, with a small bang, only by using a tool to apply pressure to the end of the crank - after having protected the nose of the crank with a smaller bolt - with a larger bolt, one which fits the internal thread on the rotor itself. An engine mounting bolt is the right size. The fastener bolt that runs through the rotor is a clearance in the rotor itself but fits the nose of the crank.
Mike

[pfg49]

Drewski's picture shows the terminal with the green wire. What components are (should be!) under the washer?

The taper on the rotor is a fairly large one, and we put lots of pressure on to try and get the thing to give without success. So, we boiled the kettle, and ever so slowly poured the hot water over the rotor. Before we got to the end of the water in the kettle, the taper gave way. (And without a bang!).