1135 oil leak, any advice welcome please

[1135]

My  gsx 1100ef has a persistent oil leak from what appears to be the starter motor recess, small puddle appears after a journey, oil runs down the cases (drain hole) onto the sprocket cover drips off the end of the gear shift shaft, lowest point.

Motor has new main output shaft seal, gear indicator O ring, starter motor O ring,  gear shaft seal,  all of which are dry anyway, stater motor stripped dry inside, cam chain tensioner dry, pressure switch dry, base gasket is dry, I cannot find how it is getting out, there appears to be plenty of the GSX motors with this problem but has anybody ever fixed it?

I would be grateful of some advice please, thanks.

[Blubber]

welcome to OSS 

[johnr]

check that its not from the front centre cylinder head stud nut o rings that have perished and the oil isnt being blown through by th wind as you ride.

[Blubber]

You have already checked my usual suspects...  So i am out of sensible options. 

 

Pretty sure more will chime in and share their thoughts

[Wolf]

Not shore if tge crank case vent is the same as on the GS at the top of the tapet cover ? When mine wss open it whould send oil to the starter cover ...

[1135]

Thank you for the replies so far, I added a second c/case breather from the usual filler cap still just the same, checked all the c/head studs all dry as is the base gasket.

Just been out again, the only place that is wet with oil is the drain hole from the starter motor recess, remove the starter motor and it is wet underneath but I have changed the starter o-ring, has any body had a problem like this? It is also interesting that the generator cover gasket  when you remove the starter does obscure some of the hole . I was wondering if it was making like a pocket that retains some oil infront of the starter., still does not explain how it gets out!

I have checked the part number for the s/motor it is the correct one.

Starting to become annoying.

Thank you, Richard

[Dorkburger]

I was thinking starter O ring as well.  Possibly damaged on install, or incorrect one?

[arnout]

I once replaced the large o-ring on the starter motor to fix a leak, but as the new o-ring didn't stop your oil leak I reckon the source must be elsewhere.

2 hours ago, 1135 said:

 It is also interesting that the generator cover gasket  when you remove the starter does obscure some of the hole . I was wondering if it was making like a pocket that retains some oil infront of the starter., still does not explain how it gets out!

This area inside the alternator cover where the wires go into from the hole, is supposed to be dry. If I understand correctly this is not the case on your engine? The wires from the stator are fed through a D-shaped rubber seal/block. But perhaps that bit is missing or damaged allowing oil to pass through?

[Dezza]

If you changed the alternator gasket, did you remove all the electrical terminals to the reg-rec, pull them out, thread through the hole in the new gasket, and then put it all back together or do what everyone else does and cut the gasket, and then use a bit of 3 bond or hylomar on the join? If it's option 2, your leak may be somewhere there and getting into the starter motor recess from outside on the case. A long shot I know but as said above all the other options have been explored.

Edited July 6, 2018 by Dezza

[1135]

Thank you, I will remove the alternator cover gasket and fit another one, I only use genuine parts, but maybe it is a pattern one  not fitted correctly. The starter motor "O" ring was genuine as well, i will check it has not been pinched.

I hope it is something as straight forward  as the gasket, I have been getting paranoid just lately that there is a crack somewhere because it only leaks when it is warm and being ridden.

I will post some photos when I have got the casing off.

Many thanks, regards Richard.

(PS did anybody get into the 10s with a completely standard 1135??, mine ran 11.02 @127mph at Santa Pod when new, many years ago, (not this one though) main limitation was the rider.)

[JRR]

I had the same leak when it sat at the side stand, and couldnt find the leak ,I reaaly tried everything ,

so by a luck and just coinsidence I discovered that the oil rubber ring(oval) that is under the plate that the oil pressure switch and oiltemp switch was leaking, tried to thighten it down,but it didnt help,

Than I changed the rubber ring for the plate the sensors are mounted in and the o-ring on both the pressure and temp switch ,thightened it all down, and ----viola -no moore oil leak the oil leak on to the top of the gear casing behind the cylinders,

and the leak from the sprocket cover gear shifter was also just gonne,on  the egde that is  the front sprocket cover screwed to (the top of the gear housing/block there is a hole on the top inside , that is there  for leding water and stuff away from the top of the engine so the fluids not shall collect on top of the engine , under the carbs and fill up the starter outsparring ,

and when the oil leaked out that hole the oil poured on inside of the sprocket cover from the top,so  the sensor plate oil leak ended escaping there and  if I sat the bike on its side stand the oil poured from top of gearboks , trough the hole in the  cover for the front sprocket and came out under ,started dripping from gear selector and the lower edge on the engine ,looked for sure like it was from under the side cover the leak was BUT SO WRONG WAS I,it was the rubber seals on the pressure switch and its mounting plate the leak was located .I was sure it came from under the sprocket cover ,

but now after changed the seals on pressure /temp plate and, cleaned well under the cover and on the top of the gear housing,

the leak is stopped on the top , and after that never have my bike shown sign of oil leak  neither from sprocket cover or gear selector or any other place and this and now a bout 6months since now, and it was quite a large leak, absolutly visible on the road and pavement after it had been parked for 10 min or more,no leaks since I fixed this  have passed and several 1000km

 

the oval rubber seal for the plate cost 7£ and the o-ring for the pressure switch was 2£

Edited November 14, 2019 by JRR

[gs7_11]

Have you checked the surface that the starter motor o-ring seals against?

Needs to be unscratched.