Starter motor just spinning

[SebastianP]

Hi guys I’m absolutely frustrated I’m building a cafe racer and my starter motor got new bushings etc and seems to just spin but my battery is fully charged etc I checked the polarity of the wires and the inside of the starter but no prevail any ideas ??


Bike is 1991 cb750 nighthawk

 

[Loose Chain]

How is the starter clutch?

 

[SebastianP]

How is the starter clutch?

Seems fine I can spin one way with my finger but can’t the opposite direction

 

[Loose Chain]

Did you try the starter on the bench? If it is on the bike and just spins then it can't be engaging with the clutch.

 

[SebastianP]

Yep tried it on the bench I’ve rebuilt it and it’s fast and smooth if I reverse the polarity directly on the battery it wants to turn the bike over but I can’t understand why only on reversed polarity

 

[Loose Chain]

If you are saying positive and negative swapped around then you have something backwards in the starter.

 

[SebastianP]

I thought so too but everything is triple checked but will try again seems odd as all I’ve done really is change the bush plate

 

[brettp]

How are you hooking up the battery to the starter on the bench? Where are you putting the wires?

 

[SebastianP]

Got the positive terminal on the starter via the positive on the battery then the negative somewhere on the body of the starter to the negative on the battery etc

 

[SebastianP]

Updated guys fixed the problem I brought a new bushing plate for my bike but a slightly different design the bushing that’s got no wire inside instead of being at the 9 o’clock position it’s at the 3 o’clock where my pencil is.

 

[Travis]

Thank you for posting your solution. That will help people when they find this thread with future searches.

 

[BIKERDAD]

Yes it will as I'm doing a complete rebuild and my starter is one part I'm going to be rebuilding so I'll guess I need that part aswell also one very big thing rubber washer that goes between the body of the starter and the lid as mine has snapped . Hope they do that part . Or i it will leak water in to it .

 

[SebastianP]

Definitely need that rubber washer/gasket

 

[BIKERDAD]

Can you buy that part ??

 

[SebastianP]

Can you buy that part ??

Absolutely you can build rebuild kits if you haven’t already that’s what I did.

What year is your bike?

 

[BIKERDAD]

Hi its a 96 P reg fn2 . Iv stripped the bike to bare parts the swing arm in in being powerdcoated . Then wheels are being redone in black as there gunmetal and pain to keep clean . Then the frame done in silver . Then it's all parts and new bits fitted back on . I'm going to chop the wir harness to move all blocks out the head light to under the seat .

So when I put the bit back on any damaged rusted will be binned and nice shiny new .

 

[BIKERDAD]

Well got round to sorting the starter and it was full of grease the whole thing the copper coil and the tube the copper coil sits in n spins so I striped the whole thing down to bits cleaned it and put it back together. I still need to buy the rubber O ring and the new brushes . Then wipe down an lick of paint black matt to match the rest ...

 

[hunterbooth1993]

Updated guys fixed the problem I brought a new bushing plate for my bike but a slightly different design the bushing that’s got no wire inside instead of being at the 9 o’clock position it’s at the 3 o’clock where my pencil is.

I'm having what seems to be the same problem. Where did you get the different plate I'm thus far unable to find one with that design

 

[SebastianP]

I'm having what seems to be the same problem. Where did you get the different plate I'm thus far unable to find one with that design

What country are you in I’ll look for you