# 4 cylinder

[steve'o']

Hi guys, I'm have a bit of an issue, and I was wondering if anyone else has run across this before? I have a Gen 1 FJR, took it out of winter storage a couple of months ago. I changed the oil, new air filter, and checked the air box for rodents, none, changed the brake and clutch fluids and took it out for a spin. It seemed to be working, "poorly", no power. Fast forward a couple of weeks. My friend, a 25 yr + Yamaha mechanic checked it and found #4 plug was fouled and sparking out the side of the plug. He said it could have been bad gas, or a bad plug, maybe needs to have a TBS done too. I replaced the plugs did a TBS and she works like a charm, until yesterday. I installed my new LED aux lights and while I was trying to aim the lights I noticed it was running rough AGAIN! Check the plugs, and sure enough # 4 is all carboned up. I called around to 3 different spots and one guy said it could be the coil for # 1 & 4 cylinder, half of the coil working. The second guy said if the coil was gone it would affect both # 1 & 4 not just # 4 cylinder. The third guy agreed it probably wasn't the coil. They all agreed that none of them have never seem an injector go, so that would be a long shot. Well I put another plug in it, ran some injector cleaned through it, checked the resistance in all 4 of the plug boots, all 4 showing 10.5 ohms at 20K reading, popped of the injector wiring harness, cleaned that and put dialectric grease on it, even snipped a 1/4" off the # 4 plug wire, dialectric grease on that, reinstalled everything and went for an hour ride. My buddy said when I hit the throttle hard the bike puffed out a bit of black smoke from the right pipe. The bike worked fine for the ride. What am I missing here? I am heading out to Laconia on June 10 for a week, and going into New York state while I'm there, and I am now really under the gun for a mechanic and getting something done. My mechanic friend said it could be another bad plug again, but what are the odds of that? He said take a couple of extra plugs and go. I'm now brain dead on what may be the problem and I am certainly not a mechanic! Any help would be appreciated.

 

[Greb]

Did you do a compression test?

 

[SkooterG]

Sounds like a bad injector to me.

Swap two of them to test the theory.

You know you can get them cleaned for relatively cheap.

 

[steve'o']

No I haven't, not sure how to do it, and anyone I contacted, mechanics, are all booked up for the next 2-3 days. I hope to be able to get it in before I go, and if I need any parts they don't send an order out until Mon. and it doesn't come in until next Thurs. leaving me just next Fri. if I do need any parts. Thanks Greb

 

[steve'o']

$175 for an injector and I might get it next week if I cross everything, and if I'm lucky.

 

[steve'o']

So will running it with a bad injector hurt it? Can I run some more injector cleaner through it? Can it be removed and cleaned up some? It's like pin the tail on the donkey! :angry2:

 

[Greb]

Good luck and keep us posted, Compression tests are easy if you have a kit. The test fitting and line threads into spark plug hole one at a time. Remove remaining spark plug leads so bike doesn't fire while thumbing starter switch. Run starter till compression gauge tops out. You should see consistency among all cylinders. If inconsistent you can drop a small amount of oil into each spark plug hole and try the test wet.

 

[Greb]

So will running it with a bad injector hurt it? Can I run some more injector cleaner through it? Can it be removed and cleaned up some? It's like pin the tail on the donkey! :angry2:

I have heard bad injectors can damage cylinders and rings by wall washing the cylinders with fuel. If too rich the excess fuel doesn't allow the oil to lubricate the rings/cylinder wall/piston skirt.

Edit: This was a high performance mustang and injectors were too big, not bad. So it may not translate to your problem.

 

[Mihalis fjr]

I agree with 'SkooterG'!

Before you buy a new injector try to clean it first..

Maybe it sticking..

I never listen for a damage injector on an fjr..

 

[Fred W]

what color was the puff of smoke?

 

[03HiYoSilver]

What you could do is Switch Injectors to see if it is the Injector causing the problem.

As I mentioned to you in the previous Post, I had the same problem and it ended up being the Throttlebody:

https://www.fjrforum.com/forum//index.php?showtopic=144961&view=findpost&p=960045

"Well in my Rare particular case, it ended up being the ThrottleBody Assy. This was done after the Replacing Plugs/Injectors/ECU and Coils and handles under the YES program. This part of the System, unfortunately, Does NOT throw Diag Codes... so it was all done with Trial & Error and with RivNuts installed at the Headers to measure the CO & HC levels.

For some reason the old Throttlebody for the #4 Cylinder would not Modulate the HC levels down to the 300 PPM level but was up in the 23-2400 PPM Levels and would eventually over time Foul Out the #4 Plug."

IF you want to, you could install some RivNuts to test each Header as seen here:

https://www.fjrforum.com/forum//index.php?showtopic=28571

 

[Canadian FJR]

PM sent.

Canadian FJR

 

[steve'o']

what color was the puff of smoke?

He said it was black, like unburnt fuel, not oil/blue smoke.

what color was the puff of smoke?

He said it was black, like unburnt fuel, not oil/blue smoke.

And just a puff or two.

 

[steve'o']

What you could do is Switch Injectors to see if it is the Injector causing the problem.

As I mentioned to you in the previous Post, I had the same problem and it ended up being the Throttlebody:

https://www.fjrforum.com/forum//index.php?showtopic=144961&view=findpost&p=960045

"Well in my Rare particular case, it ended up being the ThrottleBody Assy. This was done after the Replacing Plugs/Injectors/ECU and Coils and handles under the YES program. This part of the System, unfortunately, Does NOT throw Diag Codes... so it was all done with Trial & Error and with RivNuts installed at the Headers to measure the CO & HC levels.

For some reason the old Throttlebody for the #4 Cylinder would not Modulate the HC levels down to the 300 PPM level but was up in the 23-2400 PPM Levels and would eventually over time Foul Out the #4 Plug."

IF you want to, you could install some RivNuts to test each Header as seen here:

https://www.fjrforum.com/forum//index.php?showtopic=28571

That sounds very similar, or exactly the same as my problem. My other problem is "time", which I have little or none, and the ability to get it done before my trip. I may just have to keep putting plugs in for the trip and get it done when I get back. Thanks, I better print that post off and take it with me, just so I don't get squished like a bug when I go into the dealership and present them with the problem and a possible diagnosis.lol

PM sent.

Got it, and sent you an email back. Tks Scott

Canadian FJR

 

[wfooshee]

If your exhaust is stock, coming out the right side means nothing. Stock exhaust is 4 into 1 into 2.

Mine is running very rich, sooty tailpipes, #4 plug fouls (sooty,) and lower-than expected gas mileage. I suspect a rich injector, or one which whose solenoid is sticky making it rich by feeding too long.

My plug-fouling solution has been to "rotate" the plugs, swapping #4 with another cylinder, sometimes 1, sometimes 2, sometimes 3. Bike runs better for a while, then settles into a little bit of roughness.

Haven't move the injectors around, yet, but plan to do so next time the tank is up. If the fouling follows the injector then I'll know for sure what's up. If it doesn't then I'll also pretty much know, just not exactly what, but it would point to mechanical illness in #4.

 

[steve'o']

If your exhaust is stock, coming out the right side means nothing. Stock exhaust is 4 into 1 into 2.

Mine is running very rich, sooty tailpipes, #4 plug fouls (sooty,) and lower-than expected gas mileage. I suspect a rich injector, or one which whose solenoid is sticky making it rich by feeding too long.

My plug-fouling solution has been to "rotate" the plugs, swapping #4 with another cylinder, sometimes 1, sometimes 2, sometimes 3. Bike runs better for a while, then settles into a little bit of roughness.

Haven't move the injectors around, yet, but plan to do so next time the tank is up. If the fouling follows the injector then I'll know for sure what's up. If it doesn't then I'll also pretty much know, just not exactly what, but it would point to mechanical illness in #4.

My exhaust insn't stock, but it's just cans added, nothing up front, so it would still be plumbed the same.

 

[RossKean]

$175 for an injector and I might get it next week if I cross everything, and if I'm lucky.

While it won't solve your immediate problem, new injectors can be bought on-line for under $100 ea. I would suggest swapping from one cylinder to another and see if the fouling sparkplug follows it. If it prooves to be the injector, I would just replace it. Keep the old one for an emergency spare if you can get it working.

Ross

 

[steve'o']

$175 for an injector and I might get it next week if I cross everything, and if I'm lucky.

While it won't solve your immediate problem, new injectors can be bought on-line for under $100 ea. I would suggest swapping from one cylinder to another and see if the fouling sparkplug follows it. If it prooves to be the injector, I would just replace it. Keep the old one for an emergency spare if you can get it working.

Ross

Ross

Thanks, I just happened to look at the Ron Ayers site and there were $99 on his site plus the new "O" rings and gasket. I'm going to try and line something up through a dealer while I am traveling down through Maine and New Hampshire. I'm sure someone could get me one.

Steve

 

[steve'o']

I did a compression test 175+, so I am taking it to a mechanic for another TBS and to get him to switch the #3 & #4 injectors around.