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Discussion Starter · #1 ·
I am finally digging into my project '14 FZ-09 and I have a problem with the way it runs. It has 38,000 miles on it and as soon as I got it I did a valve adjustment, even though the previous owner said he had it done. All of the exhaust valves were way out of spec, but there was still SOME space between every cam lobe and bucket. It doesn't seem to run better or worse after the adjustment.

The bike cranks slow and unhealthy, though it does always fire up. When idling, there is a noticeable miss and when taking off there is a major loss of power, until about 3000 RPM. From 3000 RPM and up the bike has full power and seems to run just fine.

I will see if I can get a video of it starting, but I can assure everyone that it is not a battery issue. I daily ride a 2015 FZ-09 and I know these bikes fairly well.

I have never experienced a burned valve on a vehicle before, but I have a feeling that is what is going on. My first plan will be to seafoam the crap out of the bike, then I will need to do a compression test to verify what I already fear.

Any insight?
 

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I think your plan for a compression check is sound and will tell you if you have a weak cylinder. One way is to simply feel each exhaust pipe on a cold start up. If one pipe is cooler longer than the others that is you dead cylinder at idle.

I had a VFR400R (V-4 engine with 14K rpm redline) that had low compression on 1 of the 4 cylinders. Still smooth and once underway (2500 rpms maybe) and once warmed up it ran pretty good all the way to 14k rpms. You can still ride it for awhile but I suspect it will get worse. Start looking at doing the repair or get a motor out of a wrecked bike and take your chances. Doing a valve job on an FZ will be a real learning experience if you have never torn into such a repair.
 
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What's your battery voltage after sitting overnight? Slow cranking...no power until above 3k RPM. These might be symptoms of a weak battery and it can't run properly until the charging system supplies enough voltage to it.

If your battery's resting voltage is less than 12.6, I'd replace it.

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It needs very low compression to create a misfire. All the leaking valves I've dealt with were around 20 - 30% low, and still ran OK, but down on power.
I can only remember one case of burnt valves on here, and it was likely it was caused by a vacuum leak.
 

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Discussion Starter · #5 ·

Listen closely to the way it cranks. It is absolutely not normal. I promise it is not a battery issue.......

Also, when I started it this morning I lightly put my hand on all 3 exhaust tubes and they all 3 felt really hot. It sure sounds and acts like its missing to me.
 

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the cold pipe test usually has to be done within 2-15 seconds of starting cold. If that is how you tested it then if they all got hot about the same time I would guess compression is ok but nothing beats the gage test to confirm and see if there are differences between cylinders.

Synchronizing the intake could smooth out the rough idle. Have you checked that the block off rubber caps where the vacuum tubes hook up? A look at the plugs might give a clue is not all the same color.


Cranking video to me seamed about right for the cranking speed.
 

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Discussion Starter · #8 ·
It's not just that the idle is rough, it is only running on 2 cylinders. In the video, the bike fires up pretty fast, but toward the end of the cranking you can hear the motor making weird noises. I need to disconnect the fuel pump and crank it over again so it can be heard better.

I checked the plugs when I did the valve adjustment and they all looked about the same. I didn't specifically look for the vacuum block off caps when I had everything apart, but I didn't notice them missing or damaged. I did not do a throttle body sync, but that doesn't make much sense. On my 2015 yellow FZ-09 I did my first throttle body sync at about 64,000 miles and it didn't change a thing.

I am riding it most of the week, so I can't tear anything down for a few days. Let me see if I can get another video of just it cranking and not actually starting.
 

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That doesn't sound like it's running on two. The loping idle sounds like it needs a TB sync. Save yourself some stress, do a comp test. Then the sync.
 
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I agree the cranking speed is fine...there does seem to be a point, at about 13 to 14 seconds in the video where it seems to catch but then continues cranking. I would do as suggested and a leak down test too. I would check the injectors are clean...I run a cleaner through every few months....cant harm.
 

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Seems to be firing on all three to me. It would be popping and farting like crazy if only running on 2.
There is an odd noise that almost sounds like a water pump belt - but of course the bike doesn't have one of those.
Did I see an APE adjuster on the cam chain? Is it too tight??
One thing that can make a bike run rough if it was OK before, is when putting the camshafts back in, it may have jumped a tooth.

There are other electrical things that can cause rough running, but a compression check first would be a good plan.
 

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Discussion Starter · #13 ·
The bike has run the same since I bought it about 6 months ago, so me adjusting the valves shouldn't have anything to do with it. It does seem to have a weird belt type whining noise while running. It does have an APE CCT so I guess I can double check that.

I have to wait until the weekend to take it apart and do a compression test. In the meantime I will post another video of it just cranking and not actually starting.

Our bikes have 2 exhaust valves per cylinder, right? If that is the case then I could have 1 bad valve on a cylinder and it would run semi ok, but still be down on power until the RPMs picked up. I know it is speculation at this point, but I am placing my vote on that.
 

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Steve H suggested a cylinder leak down test. I agree. You can get those testers on Amazon (I think that's where I got one) pretty cheap. If I remember right, I got one (new) for $20. They practically paid me to take it off their hands. Prices vary significantly, but I think all the testers are the same Chinese item. It (and a mechanic's stethoscope) will tell you a ton of stuff. Like rings (listen through oil filler), valves (intake - listen through TB's, exhaust - listen through exhaust pipe), head gasket (listen through other spark plug holes and through coolant hose), plus it gives you cylinder leak down percentages, similar to compression tester.
If you adjusted the valves, you had the cams out and, like TRchBinAZ mentioned, you could have missed a tooth and check the Cam chain adjuster.
And you certainly should do a TB sync, or AT LEAST check to make sure the caps are on. And even finding the cap on the #1 cylinder is a chore all in itself. A cursory glance won't tell you a thing.
 

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Discussion Starter · #15 ·

I just went out and checked the APE cct and did a slight adjustment, but found no issue with that.

It ran the same before the valve adjustment. Whatever is wrong, happened before I bought the bike.

Let me know what you think in the latest video!
 

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I don't hear an issue in the cranking either.

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Discussion Starter · #19 ·
You guys are making me think that I'm going crazy, lol. I will post a 3rd video tomorrow to compare the difference between this bike cranking and my 68K mile 2015 FZ that is right next to this one. The other FZ cranks very smooth and strong.

Do yourselves a favor if you get a chance. Pull that 10A fuse and crank your bikes over. If they truly sound exactly the same as my '14, then maybe your bikes have problems too......
 
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