Help Needed Please Gen I Gas in the Oil

[NTXFJR]

I bought this bike in Oct '15. The po was not exactly forthcoming with information, but it ran great when I did a shake down ride with it and the price was right, so I brought it home. Let the farkling and tune up service begin, when I had panels off doing work on different things and general tune up stuff, I found mud dobber nests and a blackend but not quite fouled #1 cylinder spark plug. That combined with other clues led me to conclude that the bike had been sitting for some time. One of the things I'd done was change to the oil, I'd noticed that the oil level was over full and smelled of gas.

Fast forward a few months, my son bought the bike when my '16 came in last April, and after a few months he finds the oil level had grown and the oil smelled of gas again. Ok, so now I think it's got leaky injectors and it's time to get them serviced. Only problem is that he lives around 3 hours away, and we don't have time to dick around with it in his apartment complex, so we opted to just buy new injectors and do a replacement.

When I was buttoning my son's feej back up today after a paint job and suspension rebuild, I noticed the sight glass was once again over full. I did an oil change and it smells of gas again. Has anyone seen this kind of issue before? TIA

[Twigg]

I have heard of this being an issue in older, carburated bikes, but never in one with fuel injection. The tiny amount of gas that could get through the injectors would boil off with the engine running, and not accumulate ... esp. since you now have new injectors.

Used oil often smells of gas. Are you sure it is gas, and not coolant?

I'd send a sample for analysis to Blackstone Labs before going much further.

You might also run a compression test to check the head gasket is in one piece. Again, that would not be a common failure.

[Hppants]

First - pull the spark plugs and verify they are clean. If you are washing the rings with that much fuel, at least one of the plugs will be very rich. If they look wet or sooty, take a dry and wet compression test. You can borrow the tester from any reputable parts house. My first guess is that you have a ring (or two) that is stuck from sitting. Use marvel mystery oil for the wet test. Maybe let it sit with some of that and see if the ring will unstick. Squirt about 10 ml of the oil in each hole. Bump the starter (with no plugs) a few revelations to move the oil on top of the rings. Then check compression. YouTube wet compression test for more information if you are not familiar with the concept. If one hole is a lot different than the others with the wet compression readings, then a ring is stuck in that hole. Put another 10-15 ml of oil in that hole and let it sit overnight. Recheck in the morning. I've seen marvel mystery oil unstick rings. It works.

I suppose a leak down test would definitely prove this or a valve issue. But that is more involved and you probably don't have access to the equipment.

Another thought is that the gas is getting through the PAIR system? Is that blocked off? this is unlikely because the crankcase is supposed to be pressurized and pushing oil fumes toward the air box. Not the other way around.

Finally - perhaps you could have an injector that is squirting very rich for some reason. I have no idea how to test that. And i have never heard of that condition with the fjr.

That's all I can think of for now. Start simple. Stay calm.

[raYzerman]

Agree check the condition of the plugs, then proceed with the compression testing... let us know what you find.......

[NTXFJR]

Thanks for the feedback guys. Good point on possible stuck rings.
Ok, question #1, the bike idles smooth, and runs extremely well under normal or hard acceleration, damhik. If a ring or two were stuck, wouldn't that cause an imbalance in compression between the cylinders and cause the motor be rough or buzzy, especially under acceleration? Or am I looking at it wrong?
Question #2, the oil level is growing, and it smells of gas, which causes me to think there's fuel bypassing it's intended circuit path somewhere. One of the conditions my son subjected this bike to last summer before he got his truck was daily short commutes to work and back home, somewhere less than a half mile each way. The bike never got warmed up under this scenario, and any fuel that finds it's way into the oil wouldn't get burned/evaporated off? Will semi stuck rings allow the raw fuel mixture to blow past the piston and into the oil when in the compression stroke?
Not sure if this changes the diagnosis prognosis any.

[raYzerman]

The first thing one thinks of is fuel blow-by due to stuck rings. You may not notice any performance issue because the bike is so powerful anyway, and say a 30-40% loss of compression may not be clearly evident. You really need that compression test, and a leakdown test if you have an adapter to put air in the spark plug hole.....

A rich injector/mis-fuelling would mean a bad ECU or bad injector, one of which you have ruled out, the other extremely unlikely for one cylinder.......

[Hppants]

Agree with ray. Pull the plugs and examine. Then do a dry and wet compression test and report the numbers. No point in guessing anything more.