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Honda ST1100 Section => Ask A Tech about your Honda ST1100 => Topic started by: Cnav on January 01, 2016, 10:43:57 PM

Title: Oil leaking between motor and alternator
Post by: Cnav on January 01, 2016, 10:43:57 PM
My 1999 is dropping at least a fifty cent piece size oil pool below the alternator where is bolts to the motor. Is this a seal or gasket that is leaking and how easy is it to fix. Not really keen on oil leaks for all sorts of reasons so keen to fix this up . Any advice welcome
Title: Re: Oil leaking between motor and alternator
Post by: alans1100 on January 01, 2016, 11:06:43 PM
Just looking at the generator there is an O ring that would act as a seal so it's possible it has failed. The other possibility is an oil leak from the motor above the genny. Removal of the alternator means fuel tank and rear swing arm need to come out so better be sure and check where the oil is coming from first. My cam cover gaskets have a minor leak but it's not enough to worry about. http://cdn.partzilla.com/product/oem/pz/3/e/9/3e951875bf5bc3de380bb60caed904e8.jpg (http://cdn.partzilla.com/product/oem/pz/3/e/9/3e951875bf5bc3de380bb60caed904e8.jpg)

Title: Re: Oil leaking between motor and alternator
Post by: Cnav on January 01, 2016, 11:20:35 PM
Thanks for the good news , removing fuel tank and swing arm doesn't sound fun at all . I will have another look underneath , always hard trying to work out source , definitely looks up in that area where alternator bolts on
Title: Re: Oil leaking between motor and alternator
Post by: Yorkie on January 02, 2016, 09:06:34 PM
While you are in there check/replace the fuel return hose above the alternator, they have been known to leak onto the alternator and could cause your ST to fry.
Title: Re: Oil leaking between motor and alternator
Post by: alans1100 on January 02, 2016, 10:37:59 PM
While you are in there check/replace the fuel return hose above the alternator, they have been known to leak onto the alternator and could cause your ST to fry.
Which one is that?  Nothing obvious on the tank parts except maybe the filler cap vent tube which has a three way connector in it. http://www.st-1100.com/images/st1100-fuel-tank-3.gif (http://www.st-1100.com/images/st1100-fuel-tank-3.gif)

Or is it the drain tube from under the carbs (item 34/35) http://www.st-1100.com/images/st1100-carburettor-3.gif (http://www.st-1100.com/images/st1100-carburettor-3.gif)
Title: Re: Oil leaking between motor and alternator
Post by: Yorkie on January 03, 2016, 09:09:22 PM
While you are in there check/replace the fuel return hose above the alternator, they have been known to leak onto the alternator and could cause your ST to fry.
Which one is that?  Nothing obvious on the tank parts except maybe the filler cap vent tube which has a three way connector in it. [url]http://www.st-1100.com/images/st1100-fuel-tank-3.gif[/url] ([url]http://www.st-1100.com/images/st1100-fuel-tank-3.gif[/url])



Items 8 and 40
Title: Re: Oil leaking between motor and alternator
Post by: alans1100 on January 03, 2016, 10:48:49 PM
While you are in there check/replace the fuel return hose above the alternator, they have been known to leak onto the alternator and could cause your ST to fry.
Which one is that?  Nothing obvious on the tank parts except maybe the filler cap vent tube which has a three way connector in it. [url]http://www.st-1100.com/images/st1100-fuel-tank-3.gif[/url] ([url]http://www.st-1100.com/images/st1100-fuel-tank-3.gif[/url])



Items 8 and 40
I thought that was the fuel feed from the shut off valve to the carbs - must check mine in the morning.
Title: Re: Oil leaking between motor and alternator
Post by: Yorkie on January 04, 2016, 08:53:25 PM
#8 is the main culprit, one end fits over 8mm?? fitting and the other fits over around a 10mm, the only indication until it leaks is to remove and inspect the inside for cracks.
Title: Re: Oil leaking between motor and alternator
Post by: Cnav on January 04, 2016, 10:41:18 PM
Thanks for the info on fuel lines Yorkie , walked into the shed this evening to get something and it's like a 200mm x 100 mm oil puddle under the alternator area, haven't got time to spend on it at the moment but looks like I'm going to learn how to remove the tank and more ....
Title: Re: Oil leaking between motor and alternator
Post by: Cnav on February 06, 2016, 11:59:25 PM
Well i actually found time today to start pulling the bike down and finding the cause of my leak. Removed the tank cover, the actual fuel tank which exposed the top bolt for the alt, had to remove the exhaust header on the L/H side to gain access to the lower bolt for the alt. but it was all worth it because when i pulled the alt back the O ring was broken at the lowest point which is where all the oil has been coming from.  See the pics for the O ring, now its off to find a ring on monday. if i have no luck i will order one through Honda, but i bet it will be ex Melb or more likely Japan.
Title: Re: Oil leaking between motor and alternator
Post by: Jglan10 (Onesie) on February 07, 2016, 01:25:30 AM
I have a few orings spare in Sydney if you need them or go to local hydrolics place standard o ring in big macienes
Title: Re: Oil leaking between motor and alternator
Post by: Abe on February 07, 2016, 04:20:50 AM
Thanks for the update Cnav.

Looks like they didn't push the alternator on parallel.

Little engine oil/rubber grease on the new "O" ring should help to house the alternator back into the motor, but you already know that  :thumb
Title: Re: Oil leaking between motor and alternator
Post by: Cnav on February 12, 2016, 11:01:53 PM
O ring sourced from statewide bearings in Welshpool , charged a big $2 , fitted it tonight and all fixed , well I hope so , shall go for test ride tomorrow , gave the bike a birthday as well and fitted two new Bridgestone bt30 tyres as well . Can't wait to ride . Case closed   
Title: Re: Oil leaking between motor and alternator
Post by: Shiney on February 13, 2016, 05:00:22 AM
Awesome news :runyay

Sent from my SM-N9005 using Tapatalk

Title: Re: Oil leaking between motor and alternator
Post by: laurie on September 26, 2016, 11:25:37 AM
Hi Cnav
Did you end up having to remove the swing arm, or is there enough clearance to replace the o ring without having to remove it? I need to do the same job on my ST
Thanks
Laurie
Title: Re: Oil leaking between motor and alternator
Post by: Cnav on September 26, 2016, 06:07:41 PM
Hi Laurie,

No don't remove the swing arm,  i removed the fuel tank and came in that way, and the L/H crash bar and from memory the mount it bolted to. The main thing for doing this was access to the lower bolt on the alternator . The fuel tank gave me access to the upper alt bolt. The most time consuming part was removal of all plastics and the fuel tank is  tight squeeze. Once you have removed the alt bolts you can push back and expose the ring enough to remove the old one( i found my old one wasn't put in very well and was pinched. Once you get the new one in slide the alt back in carefully and tighten up the bolts.

Hope that helps

Craig
Title: Re: Oil leaking between motor and alternator
Post by: Nigel on September 26, 2016, 06:24:56 PM
Hi Laurie,

Once you have removed the alt bolts you can push back and expose the ring enough to remove the old one( i found my old one wasn't put in very well and was pinched.
Hope that helps

Craig

Sorry found that funny :wht11.
Title: Re: Oil leaking between motor and alternator
Post by: laurie on September 26, 2016, 06:29:15 PM
Thanks Cnav
I've got to remove all of the plastics, cooling system and timing belt to do another job, so I wasn't looking forward to removing the swing arm too. Thanks for the help.
Laurie