2012 FJR1300A is running rich

[Blue is Best]

My bike has begun to run rich. Gas mileage around town and running errands is way down. Running on the road, cruising at travel speed(75 mph +) is OK but down about 5%. The last big run I took it on a couple of months ago was an eye opener. At 10,000 feet elevation the thing blubbered!! Not good. But I still got good hwy mpg.

I think it is the oxygen(O2) sensor. No code on the instrument panel but the sensors can get "slow" or inaccurate before they die. That condition would not trigger a code. I think mine is at the point getting ready to die.

Odd because I don't hear of FJRs going through these sensors. The bad news is Mr. Yamaha wants WAY too much money for a sensor. Heck, car sensors can be had for pocket change but not Yamaha!!

[Sport-Touring]

[SLK50]

Have you checked the air filter?

[Blue is Best]

Have you checked the air filter?

Oh yeah. First thing is to always check simple things first.

[jay547]

Rider error?  

[greench440]

Are you using a Power Commander?  if so, are you using it in Open loop (disconnected o2 sensor).

If you're not, your gas mileage should go up as you go up in altitude.  the FI system sensors should dial back the amount of fuel because there are fewer O2 atoms in a given volume.  

I'd check the o2 sensor first.

Chances are the sensor is probably used in a multitude of other motor cycles and cars.  See if you can find a part number interchange.

[Blue is Best]

Rider error?  

I got you on my list now.

[Blue is Best]

Are you using a Power Commander?  if so, are you using it in Open loop (disconnected o2 sensor).

If you're not, your gas mileage should go up as you go up in altitude.  the FI system sensors should dial back the amount of fuel because there are fewer O2 atoms in a given volume.  

I'd check the o2 sensor first.

Chances are the sensor is probably used in a multitude of other motor cycles and cars.  See if you can find a part number interchange.

No power commander.


As I posted originally, I believe it to be the sensor.

[Blue is Best]

My current issue is trying to find a sensor that is interchangeable with the Yamaha sensor. Yamaha wants over $200    for a sensor that is made by Denso. There has to be a sensor out there that costs the going rate of $40 to $60.

[greench440]

http://densoautoparts.com/find-my-part.aspx

[Blue is Best]

http://densoautoparts.com/find-my-part.aspx

I've tried that site. I even talked to a Denso guy and he tried the Yamaha part number and he tried the Denso number stamped on the sensor I pulled off the bike no luck. I think Yamaha signed some deal with Denso to make them but not sell them.      


I'm trying to determine if a Bosch(the inventor of oxygen sensors in the 70s) number will convert.                I just don't want to pay over $200 for a $50 part!!!!!!!!!!

[HanksXXX]

Honda Blackbirds run rich and have fuel mileage problems when their Fuel Pressure Regulator shits the bed.
No knowledge of FJR's but its a thought.

[Blue is Best]

Honda Blackbirds run rich and have fuel mileage problems when their Fuel Pressure Regulator shits the bed.
No knowledge of FJR's but its a thought.

That's interesting. I hadn't thought of that. I will do some checking on the regulator in the system.      

[greench440]

Have you tried FJRForum.com?

[Blue is Best]

Green- Thanks for the website. After some reading, it appears that the FJR1300's O2 sensor doesn't come into play until after 2,000 or more RPM and when fully warmed up. At startup the bike runs on a different map. At low RPMs is where I am experiencing the terrible richness. Must be some other sensor that is not within proper specs but not completely inoperable so no code. I will keep reading/studying before I start buying things.

 

[Blue is Best]

Been riding the bike and letting the Bandit 1250 have a rest. When I went up to Creede, CO it got 51.4 mpg and on the way back 54.6 mpg.          I have ruled out the O2 sensor. It is something related to the "bottom end" of the rpm range fueling.

Green's idea of the other FJR forum is one that I think I will try. I'll sign up and post something other there about this problem and one of the gurus can push me in the right direction.

[Bounce]

When was the last time you did a throttle body synch and checked for air/vacuum leaks? Clogged air filter? Changed an intake or an exhaust without remapping it?

[Blue is Best]

When was the last time you did a throttle body synch and checked for air/vacuum leaks? Clogged air filter? Changed an intake or an exhaust without remapping it?

Good questions.


TB synch- Never        Not to my credit for sure. But, that wouldn't cause the problem I have.

Vacuum leaks- I am going to do that in the next few days along with some other ideas I have. BTW, vacuum leak would make it run leaner!!

Air filter- Checked it before last ride. Didn't need to but ordered a new one anyway.

Exh/intake change- On my new 2005 FJR I modified the air box and installed the same Muzzy 4-1 exhaust that is on the 2012 that has begun giving me the rich bottom end problem. I modified the airbox as on the 2005. The intake and exhaust changes to BOTH bikes caused me to loose 1-2 mpg. They still ran fine and got 50+ mpg. No need for an ECU reprogram or other black magic box.

As I posted in other places, a couple years ago when the 2012 was running like it should I drag raced my best riding buddy, Steve, on his newer generation 2013 FJR1300. From a 2nd gear roll on at about 4,000 rpms he jumped me a couple lengths and as the rpms came up I caught him as we shifted to 3rd and then I left him for dead. He was astounded at the HP of my older generation FJR from the mods.


Something has gone South or some wire is jacked up to make my bike run rich on the bottom but OK when I'm cruising. I call 50+ mpg now OK.

[Baz]

I just had to replace the cylinder head on my 2006. I had a disastrous event occur on a valve check. To make a long story short, a improper installation of the valve cover gasket caused the gasket to get wrapped up in the timing chain, causing it to skip and well lets just say I ended up with 16 bent valves.

So on removal of the head I found two cylinders that had been burning rich (heavier carbon build up on the two in question. (I am running a PC III on mine.) The problem never relayed to the bike running rough, and I always sync the throttle bodies when I have it apart.

I located a used head in Pennsylvania with 18,000 miles on it. (My FJR has about 80,000 km or 50,000 miles on it). Oddly enough the used head  I received had the same carbon buildup on two cylinders (although different ones).

This issue never did present itself as making the bike run poorly or did it show up on any plug inspections, nor did I ever notice any black buildup on the exhaust pipes.  I also have run mine at high altitudes.

All I can point my issue to is throttle bodies out of sync.


Oh, by the way, r&r the engine from an fjr is best left to those with excellent puzzle solving skills, and small Japanese hands.

This little mess cost me around 400 bucks in parts, and about 6 weeks of riding season (which is a good deal of riding season here!)

Note Cylinder 1&4 have heavier carbon build up in exhaust ports.




 

[Blue is Best]

WOW! Too bad. Sorry to hear about that.          

[Baz]

The more I think about your issue, I would think C02 sensor.

I cant believe a stock FJR can run rich! (Hence why I bought the PC III)

[Blue is Best]

The more I think about your issue, I would think C02 sensor.

I cant believe a stock FJR can run rich! (Hence why I bought the PC III)

It's a little confusing to me. If you read from the beginning of this post you will see that I really don't think it is the O2 sensor. After the bike is on the road it does change AFR at different elevations and gets really good mileage at these different elevastions so the O2 senser is doing its job.

I believe it is something that is effecting low rpm range fueling. A bad coolant sensor that sends a signal to the ecu that the bike is cold which would make the ecu richen things up. Something to that effect anyway. I really need to take all the plastic off and find the sensors for a check on wiring/connections and so forth.  There are no codes in the dash.

[Baz]

My apologies, I did not review your prior comments.

I believe you are on the right path.

[Blue is Best]

Have you tried FJRForum.com?

I've been trying to sign up but I chalk my unsuccessfulness to this new technology.              

[Bounce]

I've been trying to sign up but I chalk my unsuccessfulness to this new technology.              

New (cloud-based) forum just went on line this week. Go to httpS :// fjrforum. com (without the S it goes to the old, dead location).

[Blue is Best]

New (cloud-based) forum just went on line this week. Go to httpS :// fjrforum. com (without the S it goes to the old, dead location).

Thanks. In the next day or so I will try. Maybe one of the wizards can help me on the FJR!

[Blue is Best]

Put a low mileage 2015 exhaust O2 sensor on my bike yesterday. The change did very little. The bike runs slightly better which can be attributed to the wear difference. Still scotching head on current problem.

[SLK50]

Put a low mileage 2015 exhaust O2 sensor on my bike yesterday. The change did very little. The bike runs slightly better which can be attributed to the wear difference. Still scotching head on current problem.

Although I fully appreciate the benefits, “scotching” may not be the best approach.  

[Blue is Best]

Although I fully appreciate the benefits, “scotching” may not be the best approach.  

Good catch!!!! I "usually" double check my work. Should have been scratching.  I'm a bad enough shade tree mechanic if I chose the other way I'd be in real trouble.

[HotPursuit]

Honda Blackbirds run rich and have fuel mileage problems when their Fuel Pressure Regulator shits the bed.
No knowledge of FJR's but its a thought.

My VFR had this same issue when bought it, and replacing the fuel pressure regulator did the trick.  The diagphragm in the old regulator tore, dumping fuel into non-firing cylinders.  Still Honda, but the issue sounds very similar.

Sent from my SM-G965U using Tapatalk

[Bounce]

The only time I've heard of any fueling issues has been either a plugged line or a blocked air filter. I got it once by over-oiling my Uni-filter.

[Blue is Best]

I haven't ridden either bike in two months. I think that is the longest non riding stretch for me in more than twenty years.      


Which side is the clutch on? Left I think.

[02Tac]

Did you ever get to pull the plastics and inspect the various sensors? It sounds like a coolant or air temp sensor may be the culprit. Especially if it was a sudden change. A service manual should give you the correct resistance of the sensor when cold and hot.  If you cannot find a SM, I may be able to get the temp / resistance values for you.

[Blue is Best]

Did you ever get to pull the plastics and inspect the various sensors? It sounds like a coolant or air temp sensor may be the culprit. Especially if it was a sudden change. A service manual should give you the correct resistance of the sensor when cold and hot.  If you cannot find a SM, I may be able to get the temp / resistance values for you.

To be honest there is a reason I haven't ridden in two months, I been busy!  

I have:

 - Checked plugs. They look good.                    
 - Changed O2 sensor. No real change.
 - Checked for vacuum leaks(which really should make bike run lean) OK, no leaks.
 - Checked for any codes on instrument panel. Only two were from years ago. Crankshaft position sensor which I believe was from when I adjusted valves. Removed side cover and looked and  
    everything was fine. Then, one code from when I put my foot down with no ground there. Tipover code. I removed all codes and took it for a 50 mile spin. Came back and no more codes.
 - Cleaned air filter.
 - Checked a couple of sensors. Look good. Clean connections. Have not checked actual ohm readings and such.
 - Looked over everything seeable and all looks good.
 - I am going to pull gas tank and remove fuel pump and check that.


Years ago I filled up my gas tank, when I was on the road, with about five gallons of E85. Which means anywhere from 50% to 80% ethanol. I realized immediately that I goofed big time. I babied the bike for 100 miles and refilled with good stuff. I babied it another 100 miles and repeat until the bike was OK. I am not at all worried about mechanical damage but I wonder if the ethanol swelled some seals in the FI, or other, that is allowing excess gas to squeak by which would account for my richness now.

[jay547]

I haven't ridden either bike in two months. I think that is the longest non riding stretch for me in more than twenty years.      

You just dropped a notch in my book.  

[Blue is Best]

 

You just dropped a notch in my book.