Author Topic: Oil leak started after K&N lunchbox install  (Read 234 times)

Offline Blueoval78

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Oil leak started after K&N lunchbox install
« on: July 11, 2018, 03:28:49 PM »
Hello everyone, I just installed a Dynojet stage 3 kit with a K&N lunchbox filter.  Bike runs perfect, however oil has started leaking from the right front lower side of the engine.  Hard to say exactly where but it seems to be from one of the case bolts near the generator cover.  At any rate, it leaks on the exhaust and smokes.  The leak only occurs when I ride (not at idle) and at this point, is rather minor in nature. 

Could this be a case of excessive crankcase pressure forcing oil out?  With the K&N install, I installed a generic breather cover filter on the end of the pipe that used to go to the airbox and am wondering if it is not free flowing enough and increasing crankcase pressure?

Offline qcbaker

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Re: Oil leak started after K&N lunchbox install
« Reply #1 on: July 11, 2018, 04:59:42 PM »
I don't really see how an intake mod would increase crankcase pressure. My bet is that the oil leak is unrelated to your other mods. But, I could be wrong. :dunno_black:

Offline tobyd

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Re: Oil leak started after K&N lunchbox install
« Reply #2 on: July 11, 2018, 09:19:01 PM »
does it still do it if you vent the crankcase to the atmosphere rather than through some filter? Not a solution but will tell you if your suspicion is correct?

Offline Blueoval78

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Re: Oil leak started after K&N lunchbox install
« Reply #3 on: July 14, 2018, 01:53:11 AM »
Ok, so after further examination looks like I need a new right side engine case gasket.  It appears to be leaking near one of the bolts.  Probably a coincidence that it started leaking after the mods.  Next question, is it hard to replace this gasket - meaning, should I be aware of any special tricks or anything when popping off this cover?

Offline sledge

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Re: Oil leak started after K&N lunchbox install
« Reply #4 on: July 14, 2018, 11:27:41 AM »
Nothing difficult about getting the cover off.
You need to disconnect and remove the trigger and pickups first. While you are at it you may want to consider replacing the oil seal behind it while you have easy access to it. Also disconnect The oil pressure switch.

Don't be tempted to pry the cover off, if it sticks tap it with a soft mallet to break the bond.

The old gasket can be very difficult to remove. I don't like scraping the remnants off the mating surfaces because of the risk of damage and my tip is paint stripper. Dab it on with an artist's brush and after a few minutes the gasket will soften up and can be wiped off. Obviously and it goes without saying that you don't want to get it on any painted surfaces.

Offline tobyd

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Re: Oil leak started after K&N lunchbox install
« Reply #5 on: July 14, 2018, 11:31:49 AM »
Which side do you mean by Right?

The generator cover is the Left if you are sat on the bike facing forward (in case you ride facing backwards :))

The right is the crank bolt, timing mark, and clutch.

I've only gone behind the left (getting the engine back into the frame was only going to easily happen with this cover removed) and was an exercise in patience removing the old gasket. Nothing interesting behind it otherwise. Because its all aluminium or some alloy thereof you can't use any metal tools / razor blades with any force or you'll wreck the surfaces. Gasket remover might work well, I didn't have any. A brass wheel in a dremel might work too, a real brass wheel (that isn't 'magnetic brass') seems harder to find that it should be. real dremel ones seem to be, others seem to be something else with brass coating. pays money / takes choice.

The Right hand side is more complex as you'll need to remove the signal / timing wheel.

remember to remove the oil first too :)

 

Offline Blueoval78

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Re: Oil leak started after K&N lunchbox install
« Reply #6 on: August 14, 2018, 06:15:58 PM »
Ok, got the gasket installed on the clutch cover.  I put in a new oil pressure sending unit and crankshaft seal while I had the cover off.  No leaks from the gasket at all, however the crankshaft seal is leaking.  I was very careful putting it in; I put some oil on both the cover and crankshaft sides of the seal during installation.  I also made sure the shaft had no damage present.  It doesn't leak at idle but as soon as I blip the throttle, I can see the oil leak out on the bottom side between the crankshaft and seal.  Any idea why a brand new seal would be leaking?  Would there be a magical trick to fixing this without taking the clutch cover off?  It was such a dirty job changing that gasket that I really don't feel like taking it all apart again!

Online mr72

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Re: Oil leak started after K&N lunchbox install
« Reply #7 on: August 15, 2018, 12:32:09 PM »
I have also fought a losing battle with the right side crank seal leaking. In my case it leaks only on prolonged higher rpm riding, like an hour on 60mph highways or up and down through the gears. New seal didn't fix it for me.

Offline sledge

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Re: Oil leak started after K&N lunchbox install
« Reply #8 on: August 15, 2018, 04:31:30 PM »
Check the breather on the top of the valve cover.
If it's blocked crankcase pressure can force oil past the seals, especially if the rings/bores are beginning to wear.

Offline Blueoval78

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Re: Oil leak started after K&N lunchbox install
« Reply #9 on: August 15, 2018, 05:41:17 PM »
I did check the breather hose thinking maybe I had excessive crankcase pressure since I put just a PCV filter on the end of it after installing my lunchbox.  It's not plugged and I can feel pulsing at idle but nothing at high revs.  I also pulled the dipstick out to relieve any potential pressure and the leak persists even with the dipstick out.  I can feel the same pulsing at idle coming out of the dipstick hole.  Should I feel something when reving above idle? 

Also, I know many others have asked about changing the crank seal without removing the clutch cover and most people say no since it's pressed in but what if I "gently destroyed" the seal, pulled out the bits and pressed in a new one from the outside?  It was such a pain removing the clutch cover gasket and sealant that I don't feel like going through that exercise again just to find a leaking seal yet again.

Thoughts?

Offline sledge

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Re: Oil leak started after K&N lunchbox install
« Reply #10 on: August 15, 2018, 07:32:54 PM »
You did install it the correct way around?

With the spring facing inwards?


Other than that and assuming it wasn't damaged or distorted when fitted I can't think of a reason why it should leak  :dunno_black:

Offline Blueoval78

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Re: Oil leak started after K&N lunchbox install
« Reply #11 on: August 16, 2018, 01:13:53 AM »
I actually got a brand new clutch cover from eBay since I damaged the original trying to scrape off the old gasket.  I used it as a reference and installed the new seal the same way in the new cover.  One thing to note, neither the old or new seal had a spring in it.  I also checked the parts fiche and didn't see a spring on that?