Gas smell in oil - Leaking injector?

[KALLEWL]

I have a FZ6 S2 2009 at 46K km - Problem is oil is smelling a lot of fuel. I usually drive longer trips of 30-40 km and sometimes 200-300 km, so shouldnt be due to short trips. My guess is it is a leaking fuel injector that when it sits leaks fuel into the cylinder from residual pressure, which then seeps past the rings into the oil. Anyone have experience with this? I am thinking about removing the injectors and cleaning them with a 9V battery and carb cleaner, both backflushing and from the supply end. Any ideas if it could be something else?
Otherwise it runs good, maybe a bit uneven idle and a very slight hesitation for just a millisecond every 3-4 sec, not sure if this is normal. Pulls good and no stumbling or anything.

 

[Gary in NJ]

I think your diagnosis is good and worth exploring. I believe that there are o-rings in the injectors, and if one has failed a simple cleaning may not resolve the problem. A dirty injector will result in poor performance, whereas a failed o-ring in an injector would result in an injector that has poor performance and a leak as you describe.

 

[KALLEWL]

Thank you for the reply. And i guess if it is a leaking o-ring inside the injector there is no fix other than buying a new one? Also is it possible if it is just a dirty injector, that it is keeping it slightly open during stationary and not making significant problems during riding as they are mostly open then?

 

[TownsendsFJR1300]

I agree with your diag.

I'd try to narrow down which one. The top of the piston will likely look cleaner than the others (seen with a bore scope).

The spark plug may look different too..

Dunno if I'd run it as is. Should it get worse, you could get a hydro lock and bend a connecting rod.


On the same subject Gary, is Sonic Cleaning the preferred / usual way to clean them (plus testing the spray)?


.

 

[Gary in NJ]

From what I understand the injectors are rebuildable. I haven't done it, so I can't give any guidance. I do know that one of our members @trepetti sent his injectors out for a rebuild service.

 

[Gary in NJ]

Here ya go...$20-$30 per injector.

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