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Post Info TOPIC: Starter motor - removing and replacing a starter motor plus checking brushes


Super Guru

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Starter motor - removing and replacing a starter motor plus checking brushes
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If your starter doesn't turn over there can be a number of things causing the problem - these are the most common:

  • Starter button can give trouble - my bro' has to press his quite a few times to make a connection sometimes
  • Solenoid
  • Starter motor bushes
  • A bad connection in the starter circuit

Although not recommended, a quick check to eliminate a starter motor problem is to bridge the two large terminals on the solenoid occupied by the large red and black wires or to take a thick wire straight from the +ve on the battery to the insulated terminal on the top of the starter. Bit awkward to get at so be very very careful! If the starter turns over then its probably a faulty solenoid. If it doesn't then it could be the starter brushes.

On the last two occasions that I have come across starting problems it has been caused by sticking bushes in the starter although it is a bit fiddly getting out the starter to check. If the solenoid is clicking and the starter doesn't turn over try giving it a clout or three with the (non-metal) handle of a screwdriver. If that brings it to life then it is almost certainly a problem with the brushes.

A recent example was where a  friend was having trouble with her TTR starter. It started as an intermittent fault and then it stopped working altogether. The switch was OK and there was a healthy click from the solenoid. A tap on the starter would get it turning over indicating a problem with the brushes or commutator.

Removing the starter is straightforward but a bit long winded!

First remove the header pipe and then take the Jubilee clips off the shock reservoir and park it out of the way.

Then undo the three union bolts on the oil line being careful not to lose the washers or drop anything nasty into the oil holes. Once removed just pop the lower two bolts back in the holes to stop anything falling in.

See pic below to show removal of the oil pipe.

Starter_removal 001a.jpg

Undo the nut that holds the lead onto the top of the starter and its two retaining bolts. If you have a slim 10mm spanner to fit underneath the black starter lead terminal that will help prevent straining the terminal post. I didn't have one so ground down  a spare spanner to fit.

Starter_removal 013.jpg

 

 

It makes the job easier.

Starter_removal 014.jpg

 

Next, remove the 10mm bolt that holds the clutch cable retainer in place and move it out the way.

Starter_removal 016.jpg

 

The starter can sometimes be reluctant to pull out so a bit of gentle persuasion at the generator cover end helps.

Starter_removal 017.jpg

 

It is difficult to write down exactly how to extract the starter but it's basically a case of rotating it whilst wiggling it out - no force needed!

To get it past the timing chain tensioner I recall it needing to be upside down!

Starter_removal 020.jpg

 

Rotate through 180 degrees......

Starter_removal 018.jpg

 

and out it comes biggrin

Starter_removal 019.jpg

 

 

In case you want to cut corners (I tried!), it isn't possible to take the starter out from the LH side as the carb is in the way. So it has to come out the RH side. To be honest, I have watched someone take a starter out the LH side but they had to remove the generator cover to do it no

Before stripping down the starter make sure there are some marks on the body so that it all goes back together the right way. Having put a body back the wrong way around once before (it makes the starter run backwards!) I now put two scribe marks on one side and a single on the other.

Starter_removal 004.jpg

On the motor I was checking, one of the brushes was stuck.

Starter_removal 005.jpg

Starter_removal 006.jpg

I cleaned the offending brush up with a bit of emery and it now moves freely.

Starter_removal 008.jpg

 

If you need a new brush set then see here

Starter motor brushes.jpg

 

To prevent oil leaks from the oil feed pipe, I annealed the copper washers (heat to cherry red for a few minutes and then quench them in cold water) before putting everything back together again.  This should save any hassle with consequent oil leaks.

Starter_removal 009.jpg

This particular starter was new not long ago but I am guessing limited use and storing the bike outside under a cover may have contributed to a bit of corrosion building up. Anyways up, all was working fine after cleaning up the brushes! 

Whilst you are in the area, and especially if the starter pinion teeth are damaged or worn, the large gear is easily removed for examination once it’s cover is removed – see pic below.

 Sprag_clutch_repair 005.jpg

Replacement of the starter is almost a reverse of the procedure.

I have large hands so it's tricky to get in there to refit the terminal nut on the starter. I make the job easier by locating the nut first using the end of a magnetic screwdriver (thank you Mr Lidl! wink

Starter_removal 022.jpg

Even though I have stripped and rebuilt quite a few TTR engines I always work from the workshop manual on reassembly.

Any problems just post a message here.

Brian

PS I had are request from Joel in Australia for some ideas to sort out his after-market starter motor.

When he pulled the body off his starter's armature, the magnets had come adrift of the body (unglued) and hence got caught up in the starter armature itself.

This had been a bit of a problem for him over the past few rides, where the starter/solenoid would ‘click’ but no starter spinning up and heating/melting of the main starter cable if the button held in.

He thought it a dodgy solenoid but now realises it was because the starter itself was jammed up internally. This starter was lucky if it had 100 starts on it and a grand total of about 20hrs in service (on the bike)

This was the second motor he had bought from the same seller on eBay which both developed the same problem.

I have a box of dead starters most of which were taken out of commission because of damage to the pinion gear caused by a worn sprag clutch. I found a good body from an original starter motor and sent it over the water and was pleased to hear back that it fitted and the starter now works fine wink

I have heard from another UK owner who had the same issue but resolved that with a replacement starter motor as we hadn't realised that the original starter body would work with the after-market starter motors - but we do now! biggrinbiggrinbiggrin

I hope that may help someone now or in the future.

 



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Super Guru

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I have been asked how water gets into a TTR starter motor. There are 4 seals as shown below - check them all for possible damage. The most likely culprits are the large pair of seals that join the three body sections together. Replacements available here.

Seal location.jpg

Seal on terminal.jpg

 

Brian



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I have a question about the brushes. I'm in Madagascar so ordering or buying off the shelf is usually not possible.
Do you know if these brushes are identical to any other yammy or other motorcycle's? Especially newer ones. It would make my search a lot easier if I could just ask for a more recent and familiar model's brushes.

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Guru

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save hassle just order ones from totally t t r/s you know they will be correct john

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