2004 FZ6 Exhaust Melting Seat/Plastics

[Plokon]

So I bought a 2004 FZ6 yesterday. It only has 2500 miles on it, so it has done a lot of sitting around in its lifetime.

My problem is the exhaust pipe is getting really, really hot. Hot enough that it has melting some of the plastic under the seat, plastic on the seat, and melting some of the cosmetic plastic on the outside of the bike.

I can smell raw fuel when I start it up, I think it is running too rich. There is also a lack of power until I get up to ~6k RPM, enough of a lack of power that it makes it hard to get the bike going and it 'rumbles' at low speed like i need to pull the clutch in. (Edit: I started with riding a ninja 250 which seems to be a lot more linear in power delivery, so it might just be me not being used to the new/bigger bike.)

Do you think it is safe to run if it is melting the plastics? I don't want to harm the engine from it getting too hot.

From my research I've found it might be gummed up fuel lines or the TPS sensor. The dealer I bought it from said they cleaned the fuel lines out, but I still think that might be the issue.

I've only put 5 miles on the bike in a parking lot, so I haven't driven it much. I really don't want to melt any more of the plastics, the bike is in amazing condition.

Thanks!

 

[Andz]

I have a 2004 and the stock pipe had a plastic cosmetic housing on the end mufflers which implies that the pipe shouldn't get that hot.

 

[Motogiro]

:welcome:to our great forum!

When your engine is cold it will running richer than when it's cold. The ECU or ECM (electronic control unit or module) computer get's readings from sensor and adjusted fuel mixture accordingly. Clogged injector can cause fuel problems but there are many anomalies that can cause fueling problems. If the dealer knows there is a fueling problem it should have been corrected before the bike was sold. Fueling problems that cause overheating are serious but I don't think running rich as much as running lean would cause overheating. Your exhaust system, because it is under seat must have all of it OEM components which include a heat shield. I remember a fiberglass type shield related to the under seat exhaust.
Another consideration might be the catalytic converter that is housed in the mid-pipe on your exhaust. If this were passed it's healthy life it may be overheating.
Again welcome and I hope it works out for you. Maybe take it for a street ride and see if it reduces the overheating effect but to tell the truth if the seat is melting I wouldn't ride it anywhere.

 

[Andz]

:welcome:to our great forum!

When your engine is cold it will running richer than when it's cold. The ECU or ECM (electronic control unit or module) computer get's readings from sensor and adjusted fuel mixture accordingly. Clogged injector can cause fuel problems but there are many anomalies that can cause fueling problems. If the dealer knows there is a fueling problem it should have been corrected before the bike was sold. Fueling problems that cause overheating are serious but I don't think running rich as much as running lean would cause overheating. Your exhaust system, because it is under seat must have all of it OEM components which include a heat shield. I remember a fiberglass type shield related to the under seat exhaust.
Another consideration might be the catalytic converter that is housed in the mid-pipe on your exhaust. If this were passed it's healthy life it may be overheating.
Again welcome and I hope it works out for you. Maybe take it for a street ride and see if it reduces the overheating effect but to tell the truth if the seat is melting I wouldn't ride it anywhere.

You mention the cat being past its healthy life, mine is still original after 11 years and 52,000km and I have no issues with it. I have Akrapovics on mine and they run cooler than stock but even when I still had the stockers my wife never complained about her bum getting hot so something is seriously amiss.

 

[Motogiro]

You mention the cat being past its healthy life, mine is still original after 11 years and 52,000km and I have no issues with it. I have Akrapovics on mine and they run cooler than stock but even when I still had the stockers my wife never complained about her bum getting hot so something is seriously amiss.

Yes, I don't mean past the healthy life because of mileage as much as what health the engine has had or fuel that has been burned which in turn can hurt the CAT...

 

[TownsendsFJR1300]

If you still have some warranty on the bike, I would bring it back in..

As noted, the stock muffler is a heat sink BUT shouldn't melt ANYTHING.

When/if you melt a wiring harness, things will get really bad..

Aftermarket pipes DO help alot, are considerably lighter and don't hold nearly the heat as the
stocker

Replacing the Cat (part #8); 2004 Yamaha FZ6 (FZ600SS) Exhaust | Babbitts Online with an aftermarket straight thru pipe should also help..

As noted, the bike will run richer when when cold(a minute or two this time of the year), but shouldn't be stumbling until you hit 6k. Something isn't right. There are some adjustments (CO) that some one may have jerked with. Did you happen to see any aftermarket Power commanders/or similar devices under the seat?

Often disconnecting the battery for say a half hour, re-sets the ECU which may help (but I think you have bigger issues than that)

Mine will pull cleanly from just off idle to redline, smooth, no jerkiness, etc..(it is an S2 and Yamaha did change the fuel mapping some)

 

[Plokon]

I didn't buy it from a yamaha dealer, it was a used bike from a ducati place, so sadly no warranty.

It is pretty much 100 percent stock too, no power commanders or ECU changes.

How much change do you think I could do with the CO adjustment? The bike really seems to go after like 6k but I doubt I'd be able to pull from idle like you say. It just seems really hard to drive.

 

[TownsendsFJR1300]

The engine really doesn't "wake up" until 6k and start to pull hard.

The CO change wouldn't make that much of a difference.

Being its a US model, you have to to some minor mods (adding one wire carefully to the harness) to even get to the CO #'s and to adjust. Usually, stock CO #'s are all different per each cylinder.

The below member has written several threads on the procedure.

Something you can do (at least for the heat), is pick up some automotive header wrap. Cutting it into appropriate sized pieces and placing it atop the muffler. This would be in-between the header and frame/fender, etc.

On my own bike, I made up some small pieces (especially around the passenger seat). I used the super shiny and sticky A/C foil to hold the pieces together. Do NOT put the foil up against the muffler.

That should prevent any melting of parts, but you still have an issue on why its so hot.

IF you can make/post an audio / video of the bike starting cold, warmed up and maybe a short ride would help.


Here's a short video of my bike (showing voltages) from dead cold however, you can hear / see how the engine performs as it warms up.

Is yours similar to this? https://www.flickr.com/photos/127092600@N08/ I do have open Scorps so it's a little louder and the bikes in the garage.


[MENTION=15974]FinalImpact[/MENTION]




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[FinalImpact]

For the record typical exhaust gas temperatures nearer the head range from 900F to 1400F are not uncommon. I'm not saying the header is going to measure 1400F on the outside, but its going to be hot and most of the 3 way cats reburn extra fuel around 1100 to 1400F so the exhaust does in fact run hot these days.

As for what is happening that causes yours to exceed these temperatures, well we need some detail.
One has to wonder WHAT THEY POURED INTO THE TANK???? Is that the soul cause? Some additives can be very bad especially if excessive.

IME: retarded ignition timing is the biggest single contribution to increased exhaust temps. But this isn't likely in your case.

The two things I would be looking at:
Vacuum leak
Injector issues - perhaps a leaking injector is causing the CAT to reburn at elevated temperatures??

My question to you is which area is hotter? If the Header by the head is hotter that indicates a lean condition or retarded ignition timing. If the CAT and muffler past the cat is hotter than the header, than its likely the plugs Not burning the fuel or the injectors are leaking. Both of these could attribute to the stumble or lack of acceleration under 6K. Please share an audio or video track as suggested. It could be helpful.

 

[Plokon]

So I went riding again today.

I put some AC tape on plastic bit under the seat like Townsends suggested. (My dad is an HVAC tech so he has some pretty serious reflective tape).

The one thing I noticed after doing a little riding was a 'pinging' sound, which I think came from the headers. I couldn't really tell.

I also got one of my dad's IR thermometers to check temperatures. The headers were all around 170 degrees after a very, very short ride..... except for one, which was 130 degrees. (it was 90ish out today). After riding it a little bit longer through town, the side of the bike where I was melting stuff was up around 200 degrees.

As to what was in the gas tank- The dealership I bought it from also builds race bikes, so it wouldn't be out of the question that they put in some kind of high octane/race fuel or something. The gas tank was full, so they definitely added something at the dealership.

And I'd make a video but the place I drove it to was a local Yamaha dealership, so I don't actually have the bike. One of the guys there also drives an 04 FZ6 and was going to take a look at it for me. I found in my research about the faulty throttle position sensor, so he was going to check that out for me. I also found that there was a way to check the TPS in the diagnosis thing on the dash, but I couldn't get that to work. It just said DIAG when I went into the mode. The buttons were kind of touchy too, so I might just not have pressed them right.

Thanks very much for the help so far!

I'll try and post a video if the dealership is asking too much to do repairs and I need to fix it myself. I'll try and be more comprehensive about measuring the exhaust temperature too. I was only measuring from the headers and the bit that was melting plastic and making my leg hot.

 

[Serzedo]

One thing is for sure... nothing should be melting!

From time to time I ride my motorcycle inside the city, as you may guess it's really much stop and go, on those very, very hot days (like 40ºC) mine never melted nothing and my girlfriend only says it feels the seat a little warm, notthing more than that.

"V"

 

[TownsendsFJR1300]

+100 ^^^^^ Nothing should be melting

Ask them to check the CO settings just for S&G's. Just to make sure no one set them super lean, etc.(if they can record them for you would be even better)


Good luck,

 

[Plokon]

Got the bike back the other day. Been too busy too post, but they got it all fixed.

They did the recall work on the TPS sensor and changed the spark plugs and everything is running fine. I'm still not certain how the bike went from 'running great' according to the dealer I bought it from to the state I had it in. I guess I learned to maybe take a longer test drive. Anyways. The bike works wonderfully now!