Gas in Oil-- How?

[SkooterG]

What color is the smoke? White or black?

I am very suspicious of your dealer. Sounds like they screwed something up. While a lot of good theory has been discussed here, I have never heard of an FJR with your problem. It is not because of short trips. And 1000 miles overdue on an oil change is nothing. That is not going to cause a knock imho.

What did the dealership do as part of the 12,000 mile service?

 

[crankshaft]

Thanks everyone for all the input. I'm working with MDisher to help me get the plugs changed and possibly a Throttle body sync.

I was getting a light black smoke before I took it back to the shop the second time. The bike was smoking really bad and wanting to stall at stops unless I was giving it a slight steady throttle.

I'll have to take a look back in my paperwork and see what they actually did for the 12,000 mile service.

I'll be putting some Techron in it this week and hopefully give it a good run this weekend.

At this point, I still haven't ridden it since getting it back from the shop. My experiment with leaving the bike sit and putting piece of tape across the sight glass to mark the oil level has proven that if gas IS leaking down through the cylinders, it's not enough to raise the level of the oil over several days.

I'll keep everyone posted to my findings

 

[FJR Flyer]

I use the socket in the toolkit to remove the plugs. About the only thing in the toolkit that is worth using.

 

[Geezer]

At this point, I still haven't ridden it since getting it back from the shop. My experiment with leaving the bike sit and putting piece of tape across the sight glass to mark the oil level has proven that if gas IS leaking down through the cylinders, it's not enough to raise the level of the oil over several days.

I'll keep everyone posted to my findings

I would be very surprised if fuel was dripping into the cylinders with the engine off. The fuel pump has to be running to pressurize the fuel rail which in turn provides pressurized fuel to the injectors. The fuel has to be coming through one or more injectors. Even if an injector is stuck wide open you won't get much fuel through it without the fuel pump running.

 

[03HiYoSilver]

I have an '07 with about 12K on it. I had it into the shop in March for 12K maintenance and oil change. After riding it about 500 mi. I noticed it was smoking like a crop duster. After checking the oil it looked as if it was overfilled. I drained about 3/4 of a quart to get it back to normal levels but it was still smoking.

Crankshaft,

It looks like the Shop did something wrong. If they messed something up, then please call 800-962-7926 Yamaha Customer Service-Cypress/CA and ask for the Yamaha Area Supervisor so you can document this and have them correct your bike. If you do the work yourself without doing this, you can jeopordize ANY Dealer Correction.

Don't ask me how I know this...

Good Luck with your fix(es).

 

[crankshaft]

Okay I got the plugs changed. All four were definately fouled (black). One of the plugs had the little wire thing that hangs down from the plug and the [L] completely burnt off. I'm wondering if this could be the root of my problem with gas getting in the oil. Since the plug, I'm sure, wasn't firing properly leaving gas behind and it seepind down the cylinder walls. I have already put techron in the gas before changing plugs and ran that tank down. I'll run a couple of tanks and see what happens. For now I'm not getting any smoke.

 

[Denver_FJR]

Okay I got the plugs changed. All four were definately fouled (black). One of the plugs had the little wire thing that hangs down from the plug and the [L] completely burnt off. I'm wondering if this could be the root of my problem with gas getting in the oil. Since the plug, I'm sure, wasn't firing properly leaving gas behind and it seepind down the cylinder walls. I have already put techron in the gas before changing plugs and ran that tank down. I'll run a couple of tanks and see what happens. For now I'm not getting any smoke.

Sorry, not to be doomsayer... but have you considered it broke off and is floating around in cylinder?

 

[crankshaft]

No never really thought of it. But thanks for putting that in my head. My guess from looking at the plug is that it burnt off. I'll just have to run it and see how it goes. Don't know of way to track down something like that anyways without a complete tear down and rebuild, which is way beyond my skills or pocket book.

 

[Geezer]

No never really thought of it. But thanks for putting that in my head. My guess from looking at the plug is that it burnt off. I'll just have to run it and see how it goes. Don't know of way to track down something like that anyways without a complete tear down and rebuild, which is way beyond my skills or pocket book.

If there was a piece of metal floating around inside one of the combustion chambers I would expect it to get very hot and cause detonation, which you would hear.

Since this problem occurred after you had the shop do some work on your bike, it is possible that they either installed a bag plug or damaged one of yours.

 

[RadioHowie]

Chances are real good, if the electrode came off in the cylinder, it went out the exhaust many miles ago......or is permanently welded to the piston crown.

I wouldn't give it a second thought...or tear the motor down...looking for something smaller than a fingernail clipping.

 

[ionbeam]

Maybe it's just me, but if the side electrode is BURNED off I would be alarmed and whoreified horrified. What was the porcelain color and how did the porcelain look? The cause is complicated because 2 of the plugs have the spark jump from the side electrode to the center electrode and the other 2 plugs have the spark jump from the center electrode to the side electrode. If the side electrode is indeed burned off a vacuum leak or pre-ignition would be major concerns, either can burn a hole in pistons or do other dire damage.

 

[LAF]

Maybe it's just me, but if the side electrode is BURNED off I would be alarmed and whoreified horrified. What was the porcelain color and how did the porcelain look? The cause is complicated because 2 of the plugs have the spark jump from the side electrode to the center electrode and the other 2 plugs have the spark jump from the center electrode to the side electrode. If the side electrode is indeed burned off a vacuum leak or pre-ignition would be major concerns, either can burn a hole in pistons or do other dire damage.

Yes and if it scored a cylinder wall, or fouled a ring, gas would be in the oil for sure. I mean the thing had to go somewhere? If it was Iridium it may really be more of an issue due to it's hardness, but size wise you get a break there.

I would not want it "welded" to the top of my piston as depending where, squish is pretty sensitive to changes.

I am rooting for it "blew out the exhaust port" and you are good to go.

I know I would be checking plugs with a magnifying glass and compare them to some online photos to see what was going on. I don't think a "chop" plug check is very easy to do on the FJR, unless you had someone follow you with a trailer, but I know I would be looking at those plugs and how they are burning. It is harder to do now then back in the day but you can still read plugs, it just takes magnification of some type, and one of the many good reference photos on line.

If I had a cylinder running lean(hot)enough to take a electrode off a plug, I would want to know why?

Or someone tried to adjust (ham fisted) the gap and just weakened and it fell off after the first firing or compression stroke?

I would make sure all boots and caps under the tank concerning the TB and gas vapor reclaim were checked for any kind of vacuum leak, including the TB boots and sync port caps.