[hotwheels]

I would like to inform you about a recent internal Yamaha Motor France document.
They warn Autorised Dealers about a lot of engine failures due to the use of non Yamaha-Approved exhaust lines...

Here is a mail from a french customer to SC PROJECT :

"I wish to inform you of an urgent matter of concern which is currently making the headlines among the French MT07 community.

It has come to our attention that official Yamaha sources have explicitely put into question the quality and design adequacy of SC Project exhaust lines for the MT07. We have been able to confirm the veracity of the source which states that*:

«*YAMAHA has observed an increasing number of failures on vehicles of their brand, including important engine damage on MT07/XSR700/Tracer700 due to the use of non Yamaha-approved exhaust lines, most notably SC Project and Arrow*».

Recent cases of total engine failure (breakdown) falling within Yamaha warranty period have been attributed by Yamaha to a severe flaw in SC Project exhausts. Consequently, in such cases Yamaha has considered the issue not related to their warranty. Such position is backed, according to Yamaha, by a repeated occurrence of the fact those engine failures were on motorcycles which had been equipped with SC Project exhaust lines.

As an active member among the MT07 community, I have noted the success that your brand has among our bikers in France and the strong customer base supporting you. However, the matter above has generated a heightened sense of confusion and worry among SC Project owners and potential future owners.

In order to clarify the situation both for the unfortunate victims of the engine failures which Yamaha considers due to SC Project exhaust flaws, as well as the many potential future buyers of your products, I can only urge you to contact Yamaha as soon as possible and root-cause the issue.

I sincerely believe such action would be in the best interest of all*: bikers, indutrials, and future owners.

As a supportive customer, I would appreciate being informed of the next steps your brand will take to resolve this sensitive issue."

here is the pic of the internal document (06/19/2018) :

 

[hombacher]

Hoi hotwheels,

I hope to understand right, there is an internal Yamaha notification regarding damages which are not covered by Yamaha the warranty? These are major engine damages caused by installing an Arrow or SC Project exhaust, but only on the 35 kW restricted 700s?
And an other damage to the electronics of the ABS, caused by a third party break and rear light?

Do you know what kind of damages happen to the engine?

On the other hand there is this quoted letter by French writing to SC Project? This will be fun..., I do not expect a satisfying answer from the Italiens. They will not cover the costs of an engine repair, or give any warranties by using their exhausts.

BR
hombacher

 

[hotwheels]

You understood right

I thought it was important to share this

The damages are caused by an excessive engine temperature that causes excessive oil consumption and engine failure.

 

[hombacher]

aha, do you know something about the counted damages, how many riders were affected by their exhaust tuning?

I did not hear something comparable here in Germany. But the low cost and noise orientated exhaust changing is as well very popular to the young and restricted (35 kW) MT riders. And both manufacturers are favoured because of the much higher noise.

 

[hotwheels]

I don't Know how many bikers were affected.

I just can say that 35 KW Euro 4 bikes are affected.
It comes from AFR ratio of our bikes : too lean to respect pollution restrictions.
Everybody knows what happens if you ride a too lean bike... it's worth with an exhaust line and an Air Filter.

I recommand just one thing :
- Ecu tuning to adjust AFR and engine temperature

 

[Tigerjohn]

Hmmm......I can imagine any warranty claim for engine seizure/overheating damage is likely to prove difficult if you've fitted any after market exhaust, other than the specific (and expensive!) Akra system approved by Yamaha. Best to remove the evidence and re-fit the OEM system if you have a problem! It would seem from the French document that the problem is more of an issue with the restricted bikes, so 'no worries' for most of us.

 

[Caesar243]

Wow. I try to keep an eye on internal engine temps with the speedo while I am riding and I suggest any SC project owners do the same.

I got the Yoshi Y series straight from Yamaha's catalogue from my local dealer but I had looked at SC Project and Termingoni exhausts before deciding to stick with something sanctioned by Yamaha.

 

[John A]

Wow. I try to keep an eye on internal engine temps with the speedo while I am riding and I suggest any SC project owners do the same.

I got the Yoshi Y series straight from Yamaha's catalogue from my local dealer but I had looked at SC Project and Termingoni exhausts before deciding to stick with something sanctioned by Yamaha.

I suspect that keeping an eye on the engine coolant temperature, or a temperature gauge on the oil filler cap won't give any indication of damage caused by an exhaust. I would suspect that it's the exhaust valves in particular that will take the brunt of any increased engine temperatures and the coolant temperatures won't adequatley show this increased temperature, especially if the temperature sensor is after the radiator.

 

[Caesar243]

I suspect that keeping an eye on the engine coolant temperature, or a temperature gauge on the oil filler cap won't give any indication of damage caused by an exhaust. I would suspect that it's the exhaust valves in particular that will take the brunt of any increased engine temperatures and the coolant temperatures won't adequatley show this increased temperature, especially if the temperature sensor is after the radiator.

That’s a good point. It had been crazy hot here in New England the last few weeks so that’s mainly why I had been keeping an eye on the coolant temps. It makes sense that the coolant wouldn’t register a large change if the valves and piston were slightly overheated.

One thing you can do is note the change in color of your pipes where they come out of the head though. A dark heat stain can indicate an extreme lean/hot condition too. You can also use a ir heat gun directly to the same spot of the pipes, although I’m not sure what a good control/stock temp would be though, and ambient air temps would also have an effect on that.

 

[Munkul]

I dont get why I see pics of second hand MT07's with stock exhausts, and their headers are blue. So much higher EGTs than I see on my own bike, which has never deviated from straw-brown headers.

I was taught that if your headers are blue, then you should probably find out why.

 

[Domster]

When I bought my new 60th Anniversary the advice from my dealer around header pipes was; don't start it up and let it 'warm up' just start it and get riding. That way the headers heat up more gradually, as the air cools them from the get-go. He also had a very relaxed attitude around running-in. My headers look fine to me...

 

[Major_Tom]

I suspect that keeping an eye on the engine coolant temperature, or a temperature gauge on the oil filler cap won't give any indication of damage caused by an exhaust. I would suspect that it's the exhaust valves in particular that will take the brunt of any increased engine temperatures and the coolant temperatures won't adequatley show this increased temperature, especially if the temperature sensor is after the radiator.

Vance & Hines sell titanium exhaust valves. Would that help stave off temp related engine failure?

 

[Flyerdon]

It's well known that almost all new engines these days run lean, very lean, and when the exhaust and/or intake is modified the A/F should be carefully checked and the best way to do that to ensure it's not going to destroy the engine is with a tune on a dyno. This story only supports the need to do that no matter what the manufacturer of the after market part says. Yes, it's expensive, but not as expensive as a new motor. The easy out for the exhaust manufacturers only needs to be a caveat somewhere that says it's suggested that a fueling device be added or the air/fuel ratio should be maintained when their part is used. Then, the responsibility is on the user. It is even possible to get an a/f gauge to monitor the fueling so the rider can watch what's going on. I did it with my FZ1 after installing a MIVV exhaust and after market air cleaner and I added a PC5 so I could make my own adjustments. It was a good experience building my own maps and watching what was going on as I rode. Expensive? yes but not more than a new motor.

 

[Major_Tom]

Thanks for the tips! My confusion is what exactly is considered 'lean' and why it's better to run rich than lean? As I see it, running rich provides cooling from the vaporisation of unburned fuel, thus lower temps. However, when we talk about lean vs power, as I see it eco weenies and trackday weenies should unite at perfect stoichiometric ratio (14.some:1 ..?). Each should want perfect combustion to get all the power out of the available fuel making more heat and more expansion and faster piston displacement. This is where people lose me on lean running too hot and losing power for the sake of emissions....

 

[DeYo]

Hi all! What is your usual average temperature when you are riding nowadays with this heat?