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Author Topic: Rotax Starter Overhaul  (Read 779 times)

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Offline WB650 Skylark

  • Posts: 35
  • Country: us
Rotax Starter Overhaul
« on: Wednesday September 06, 2017, 20:22:19 UTC »
Looking for suggestions. I have recently completed a top overhaul on the GM and now the Rotax starter is struggling to turn the engine even though the battery is fully charged. I am thinking it may be time to pull the starter off and get it overhauled (info from the plate on the starter:- Rotax, London, Eng., Type C0225 24 volt, CW rotation, ser No. 1575.
Any suggestions on who would overhaul the starter in the US? is it worth stripping down, cleaning and replacing brushes first to see if it fixes the problem and I recall someone telling me there is a spring tension adjustment, although it seems to engage ok and gives a 1/4 turn then stalls, so I think its on the electrical side and not mechanical.
Appreciate any help
Thanks,
WB650 Skylark

Offline Tim Watson

  • Posts: 43
  • Country: gb
Re: Rotax Starter Overhaul
« Reply #1 on: Thursday September 07, 2017, 08:58:47 UTC »
If it's of any help, there's a parts catalogue here:

https://www.scribd.com/document/192607559/ROTAX-Starter-Information

Struggling to rotate?  Bearings perhaps?

Also worth checking that the electrical connections are all resistance-free. And the same for the starter relay (if your Chipmunk is fitted with one) - corroded contacts in the relay would limit the voltage available at the starter motor.

Offline speedbird1

  • Posts: 526
  • Country: us
Re: Rotax Starter Overhaul
« Reply #2 on: Thursday September 07, 2017, 14:32:58 UTC »
Not in the US but close by is SIL Industries in BC, Canada.
They have been known to overhaul strange British electrical devices including BTH mags and Rotax generators. Probably not cheap, but then nothing is these days regarding a Chipmunk.
Speedbird 1.

Offline scchippie

  • Posts: 3
Re: Rotax Starter Overhaul
« Reply #3 on: Friday September 08, 2017, 17:49:12 UTC »
 I had them rebuild my Rotax starter. It was if I had a brand new unit. It spins the prop almost as if I could taxi on it. I definitely recommend contacting them.

Good Luck
Dan

Offline WB650 Skylark

  • Posts: 35
  • Country: us
Re: Rotax Starter Overhaul
« Reply #4 on: Monday September 18, 2017, 00:40:11 UTC »
Thanks to everyone for the advice, I took the starter off (no small task!) blew it out disassembled the brushes cleaned everything with MEK and re seated the bushes and re-assembled. Now the starter is turning over great and the strongest its been since I have owned the plane. I bought four new brushes from Skytrade but didn't need them this time, I'll keep them as spares for the future.
Thanks,
WB650 Skylark

Offline speedbird1

  • Posts: 526
  • Country: us
Re: Rotax Starter Overhaul
« Reply #5 on: Tuesday September 19, 2017, 16:17:35 UTC »
While you are in the mood, you might think about taking the generator off and giving it the same treatment??  The generator does not have a proper seal and oil mist gets back in the works so a good wash out does wonders.
Dave Watson has the brushes for the generator in California. (Splitpin Engineering)  The brushes have a good wear history, but if in doubt change them!!

Speedbird 1.

Offline WB650 Skylark

  • Posts: 35
  • Country: us
Re: Rotax Starter Overhaul
« Reply #6 on: Friday September 22, 2017, 17:43:30 UTC »
Thanks Speedbird1, I actually had the generator off to get at the starter! should have cleaned it up but at least the generator is easier to take off (mechanically that is), I'll get it off soon and clean it up (never short of work when you own a Chipmunk) and I actually have a spare generator :-)
WB650 Skylark

Offline Dick Gower

  • Posts: 275
  • Country: au
Re: Rotax Starter Overhaul
« Reply #7 on: Monday October 30, 2017, 00:23:59 UTC »
One important item to inspect when you have the starter removed is the small hex nut in the middle of the dog.  It has a LH thread.  The nut and bolt wear to the point where the nut drops off and, falls into the timing gears and, as it happened to a friend of mine, seizes the engine. More details if you PM.
Dick Gower
Melbourne,
Australia.

Offline yakxx

  • Posts: 151
  • Country: pt
Re: Rotax Starter Overhaul
« Reply #8 on: Tuesday December 19, 2017, 10:54:27 UTC »
Very interesting about the nut and bolt falling into the engine....my 'Starter Motor observations and questions ::

I recently decided to open up a starter motor that had been on the shelf for years to have a look and change the grease if dirty and check/change the bushes etc....They come to pieces very easily by the way as long as you dont require to dismantle the clutch mechanism which is not hard but I did not want to disturb the torque setting...

The bolt we are talking about ( the left hand thread one on the Starter Dod ) was tight and secure.....until i removed the nut and then it became 'floppy' in the dog itself....I then found the locking screw that holds it in at the other end...was unscrewed a couple of turns allowing it to wobble about when not pulled up tight from the other end with the left hand nut...
taking a 'new' dog off the shelf I found the bolt in the new one to be very secure and rigid within  the Dog.....maybe this contributes to the not eventually falling off the bolt and into the engine....

the brushes were great so I didn't have to change them but the grease was very old and dirty so cleaned it all out and replaced it......now , the book says use Acheson 223 ( blue colour) because its important to clutch friction and operation....looking for that grease came up with a high pressure alternative grease (still  Blue) ....but the old grease was not blue......so not very sure about the correct grease to use..eventually I opted for a blue colour high pressure grease with a code of 221 ....however ...it says the grease is important to the clutch but my clutch which worked fine last time I used this starter....was itself almost dry...( the gearing was packed but the clutch plates themselves were dry  ) ....so ..my question is ...should the clutch assembly within  the 'bowl' be packed with grease....or completely dry and furthermore should the dog itself be greased or light oil or nothing ??.....obviously the gearing should all be packed with grease ( how much ? )  but should the clutch assy be also greased /ligghtly or packed ??

finally , the left hand nut wasn't great but oh where to get one.....anybody have a new one ??

Merry Christmas 2017

Offline yakxx

  • Posts: 151
  • Country: pt
Re: Rotax Starter Overhaul
« Reply #9 on: Tuesday December 26, 2017, 11:09:28 UTC »
Any comment anybody who has been there
Type and quantity of grease and where ??
I suspect a number of issues ref engine turn over at start up may be influenced by the grease issue

Offline speedbird1

  • Posts: 526
  • Country: us
Re: Rotax Starter Overhaul
« Reply #10 on: Tuesday December 26, 2017, 17:22:49 UTC »
Dick Gower may have the answer as he is the electrical guru.
Speedbird 1.

Offline Dick Gower

  • Posts: 275
  • Country: au
Re: Rotax Starter Overhaul
« Reply #11 on: Thursday December 28, 2017, 05:31:38 UTC »
Very interesting about the nut and bolt falling into the engine....my 'Starter Motor observations and questions ::

I recently decided to open up a starter motor that had been on the shelf for years to have a look and change the grease if dirty and check/change the bushes etc....They come to pieces very easily by the way as long as you dont require to dismantle the clutch mechanism which is not hard but I did not want to disturb the torque setting...

The bolt we are talking about ( the left hand thread one on the Starter Dod ) was tight and secure.....until i removed the nut and then it became 'floppy' in the dog itself....I then found the locking screw that holds it in at the other end...was unscrewed a couple of turns allowing it to wobble about when not pulled up tight from the other end with the left hand nut...
taking a 'new' dog off the shelf I found the bolt in the new one to be very secure and rigid within  the Dog.....maybe this contributes to the not eventually falling off the bolt and into the engine....

the brushes were great so I didn't have to change them but the grease was very old and dirty so cleaned it all out and replaced it......now , the book says use Acheson 223 ( blue colour) because its important to clutch friction and operation....looking for that grease came up with a high pressure alternative grease (still  Blue) ....but the old grease was not blue......so not very sure about the correct grease to use..eventually I opted for a blue colour high pressure grease with a code of 221 ....however ...it says the grease is important to the clutch but my clutch which worked fine last time I used this starter....was itself almost dry...( the gearing was packed but the clutch plates themselves were dry  ) ....so ..my question is ...should the clutch assembly within  the 'bowl' be packed with grease....or completely dry and furthermore should the dog itself be greased or light oil or nothing ??.....obviously the gearing should all be packed with grease ( how much ? )  but should the clutch assy be also greased /ligghtly or packed ??

finally , the left hand nut wasn't great but oh where to get one.....anybody have a new one ??

Merry Christmas 2017

Definitely worth replacing both the operating rod and the nut Yakkxx because the thread on both are usually badly worn.  I got both from Skytrade in about 2011.  The rod is 16282/1 and I think the nut is 16091-4.  It is an A246 slotted type.

The specified gearbox, plain bearings and clutch grease is graphited DTD 582 (RAF 34A/79) and therefore always looks dirty.  There are no instructions as to the quantity but I have never seen one completely filled.  The armature bearings are greased with DTD 577 which I believe is equivalent to Shell grease 5 or Mobil 28.  Again no quantity specified but bearings in such applications are usually 50% filled.
To minimise wear on the nut in service it would probably be better to use the split pin installation method specified in the engine OHM for moving components where the tails are wrapped circumferentially around the nut.

Happy new year to you all.
Dick Gower
Melbourne,
Australia.

Offline yakxx

  • Posts: 151
  • Country: pt
Re: Rotax Starter Overhaul
« Reply #12 on: Thursday December 28, 2017, 14:39:42 UTC »
Thanks Dick...luckily I have complete dogs complete with the shaft ( in my stock) so I have replaced that ...managed to get the nut ...( they sell between 25 -46 pounds depending who you buy it from....so expensive I was going to machine one up myself but eventually I thought better get the correct part for safety)
Thanks for the grease info....
Have a great New Year and happy flying

Ps.  The dog and shaft sell for 250 pounds here....just in case you have some

Offline Dick Gower

  • Posts: 275
  • Country: au
Re: Rotax Starter Overhaul
« Reply #13 on: Saturday January 20, 2018, 20:28:51 UTC »
Good to hear a happy ending Yakxx.
Also good to hear that there rare still some spares around.
Thanks,
Dick
Dick Gower
Melbourne,
Australia.

 

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