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Alternative alternator cover

Posted: Fri Dec 30, 2016 1:21 pm
by Kmamac
Hi. I have been chasing a leak on the alternator side for a few weeks now. Two new gaskets, a whole load of new helicoil threads to replace stripped ones and finally the penny has dropped. For unknown reasons someone has had to TIG a very small repair near one of the bottom threads. The face is nice and flat locally but it would appear the heat must have distorted a whole section of the mating face. I know this because I managed to inset a feeler guage up past the gasket!!!!! No wonder it leaks. I guess I could take the cover off (AGAIN!!!) and get all amateurish with large amounts of sealer OR find a replacement.
Does anyone know which models are the same? I can assume the 851 is the same but what about later models?
I obviously want to simply drop in the alternator windings and just screw back in position sensor thing. There is a 748 one on uk eBay but at 280 pounds that's making me head for the large container of sealer!!!!
Of course if anyone has one to sell even better!
Best regards
Keith mm

Re: Alternative alternator cover

Posted: Fri Dec 30, 2016 5:56 pm
by angelix
280quid is a robbery, i just got one for the Paso for 20 quid and had the alternator attached.

I do have the feeling that all watercooled versions are compatible... the only issue is the stato, I know that for the ST2 there were few changes and one specific Year model was troublesome (97?) in the stator dept.

on Enay Italia there is a 98 one available for 50EUros...

http://www.ebay.it/itm/CARTER-ALTERNATO ... SwMVdYEJMO



if the difference is just few tenths of mm, you could take it to a workshop and have it milled; before going that route you could also try yourself by getting some good wet&dry sandpaper and a flat surface such as a window glass.

Re: Alternative alternator cover

Posted: Fri Dec 30, 2016 6:03 pm
by paso750
The alternator cover and the alternator of the 907ie has a different part number. The one of the Cagiva Elefant 900IE is probably the same as the one of the 907ie.
'89 851 is the same as the 906 but that won`t really help.
The cover of the 748/916 is different. Compare the insides:

http://www.ebay.com/itm/90-DUCATI-906-P ... s~&vxp=mtr
http://www.ebay.com/itm/Ducati-generato ... Xz&vxp=mtr

I would contact Rudy and see if he has one in stock if yours isn`t fixable.

Re: Alternative alternator cover

Posted: Fri Dec 30, 2016 8:52 pm
by Mc tool
cant you reface it on a sheet of sand paper on a flat surface ?

Re: Alternative alternator cover

Posted: Mon Jan 02, 2017 5:53 pm
by Kmamac
Thanks for all your wise suggestions and ideas. This forum is a bit like having a few knowledgable mates popping around throwing a few ideas about. This contrasts with some forums that are more like popping into the pub and a load of drunks don't listen properly and come up with all sorts of stupid ideas!
Anyway, I do have a mill but after trying to set the cover up I realised it did not have enough travel in the y direction. I could have done it in two goes but I don't have enough parallels clamps shims etc to be able to accurately position it a second time. However, by attempting this I did see it was flat within about 0.04 across all the face except where it was welded where it had bent out by about 1mm - yep that much.( do not want to remove that much metal)
I decided to fill the area with metal epoxy and grind flat on a sheet of glass and emery paper.
The filled length is about 10cm (4 inches).
I have applied a thin layer of sealant along the edge as well as a new gasket just to ensure it will now be oil tight.
Hopefully I will get a chance to fire her up at the weekend to confirm its oil,tight.
I will now keep an eye on eBay and when cheap one pops up I will buy it. ( only of its about 30-£40 )
Thanks for all your suggestions
Keith MM

Re: Alternative alternator cover

Posted: Tue Jan 03, 2017 9:22 am
by Derek
paso750 wrote: The cover of the 748/916 is different. Compare the insides:

http://www.ebay.com/itm/90-DUCATI-906-P ... s~&vxp=mtr
http://www.ebay.com/itm/Ducati-generato ... Xz&vxp=mtr
That 748/916 casing is from a later 3-phase 748. The 916 casing with the single phase alternator is very like, if not the same as that 906 casing. Remember too that the 907, as well as the 851/888 and 916 all have 2 timing sensors.

Re: Alternative alternator cover

Posted: Tue Jan 03, 2017 11:57 am
by angelix
See how it goes with the epoxy, if that does not work there is also another solution...

there is a "Cold" alloy solder that works a treat on cases like yours. I remember seeing a demonstration and it was the perfect solution for many cases where welding at high temp is not possible or can lead to unwanted deformation.

one example is here http://www.aluminiumrepair.co.uk/, basically is a brazing alloy that works at around 400 degC, strong enough to repair and build up missing pieces.

Re: Alternative alternator cover

Posted: Tue Jan 03, 2017 3:43 pm
by Tamburinifan

Re: Alternative alternator cover

Posted: Tue Jan 03, 2017 6:13 pm
by higgy
works great where engine heat is always low, not so great where engine parts get hot like around exhaust ports,spark plug holes et.c

Re: Alternative alternator cover

Posted: Tue Jan 03, 2017 7:27 pm
by Mc tool
I have used Devcon liquid steel ( not sure if it was epoxy ) looked just like a turd sitting there in the tin but deffinatly not shit :lol: