Petrol in airfilter

[Do-it]

My 2005 Tiger runs a bit irregular at low revs. :(  When I did some checking, it appeared that there was petrol on the air filter.
Could this be the cause for running irregular?
And -more importantly-  what could cause the petrol from poluting the air filter :?:

[Colonel Nikolai]

There is a sump breather seal that's leaking engine oil into the chamber beneath the clutch housing or something: mustang knows all about this (like he knows about everything with stripes and two wheels it seems). The information is on this forum, I just don't know where right now.

[Do-it]

Hi Colonel!
Thx for your reply.

The airfilter, however, is not poluted with oil, but petrol.

Oh and btw, the bike also coughs a little bit when closing the throttle.

[Mustang]

if you are in the 20,000 mile range Start with checking the valve clearances

[Do-it]

33k km,   so, yes definitely in that range...

Will follow up.

[Colonel Nikolai]

DOH! It would help if I actually comprehended what someone is saying. Sorry.

[EvilBetty]

Heh, I read the same thing and my first impulse was to post for him to check his centrifugal breather seal, lol.

[Do-it]

OK, just to explain the problem further:
- Air filter is a little bit wet and it smells clearly like gas. There is NO oil on the filter.
- The engine runs irregular at low rpm (especially stationary)
- When closing the throttle (e.g. entering a corner) there are some explosions in the exchaust.

My assumption: mixture is too rich at low rpm due to gas on airfilter.
The question therefore is: why is there gas on the filter.

Wrong valve clearance could indeed be the rootcause, or no healthy sparks, or ....
I will open Pandorra's box (I mean the engine) after Xmas to check it out.


Hope this message can be decyphered by the experts. :)

[Mustang]

My bets on some intakes with zero clearance on them thus remaining open .

[Bixxer Bob]

The bangs on overrun are usually weak mixture, but could be open exhaust valves also.

[Do-it]

So I admit: most of you were right. :oops:
Sump breather seal was the rootcause.

This triggered a chain of events:
Oil in airbox
Oil clogging airbox-computer hose
Computer gets wrong signals
Extremely rich mixture to polute the airfilter
Engine running irregular and HIGH fuel consumption

After replacing seal, new K&N airfilter, cleaning the airbox-comp hose and also adjusting 7 valves + new sparkplugs + some more, it is running very smooth again.

Clearly the previous owner never heard of maintenance..

Thx for your advise...

[EvilBetty]

Awesome... Glad to see you got it sorted before the warmer weather hits.

At this rate I think we'll see it in July