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help with vfr400 nc30 alternator issue.

Posted: Mon Sep 15, 2014 2:06 pm
by isca1987
I have taken my alternator cover off and about a table spoon of engine oil came out, I'm guessing this is not right? The bike was running fine but the plug from the stator has melted.
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I have the rick oliver gsxr alternator and stator on order ☺ but want to make sure the oil issue and melted stator plug isn't going to happen again.

Any help would be great

Re: help with vfr400 nc30 alternator issue.

Posted: Mon Sep 15, 2014 2:24 pm
by speedy231278
When I did mine, there was oil in there. I had to change it again after a day or two because I'd ended up with the wrong sized one for my NC35, and there was just as much oil back again. If you look at engine case behind where the stator mounts, you'll see there's a gap in it which oil can get splashed through. I don't think it's a problem.

As for the melted plug, that can be corrosion causing excessive resistance in the terminals which makes them very hot, or it could have been an issue with the stator going sick. Check your reg/rec too, just in case, although issues with that generally fry the plug at the reg/rec end not the stator end. As you are changing the stator you'll probably be ok, but it doesn't hurt to test it.

Re: help with vfr400 nc30 alternator issue.

Posted: Mon Sep 15, 2014 8:56 pm
by isca1987
Thanks very much for the help ☺ cheers

Re: help with vfr400 nc30 alternator issue.

Posted: Tue Sep 16, 2014 10:17 am
by Neosophist
as above.

oil in there is ok.

the connectors fry mainly due to getting corroded up over time..

they flow high current and with the increase in resistance from the corrosion they get hot and melt.

not always a sign of a dead genny but becuase the genny is putting out more current to overcome the reistance it can fry the genny too.

Re: help with vfr400 nc30 alternator issue.

Posted: Tue Sep 16, 2014 10:46 am
by isca1987
Great thanks it was the oil really worrying me, but I'm goin to replace the alternator and stator with the gsxr one to save a bit of weight and have better pick up ☺.

Re: help with vfr400 nc30 alternator issue.

Posted: Tue Sep 16, 2014 8:33 pm
by RickOliver
Alternators can run quite happily in air as the static and rotary components don`t actually touch but they produce a lot more heat than you might expect and are therefore run in oil as a method of cooling. The alternator typically will have a running temperature of close to 200 degrees, so bathing it in engine oil which is being kept at nearer to 100 degrees by the cooling system will significantly reduce that figure.

Rick