I think I speak for all of us when I say that I like to keep my motorcycles in as close to perfect condition as possible. I mean, I love it when my bikes look, feel, and ride like new—who doesn’t?
So it causes me a lot of stress when something goes wrong with my bikes, even if it’s something simple. Usually, I waste no time sorting out whatever issues arise, sometimes even calling in sick (sorry, Jonathon) just to tend to my beloved two-wheelers.
And so, you can probably imagine the gut-wrenching feeling I had when my trusty Yamaha MT-07 blew its engine. Okay fine, it didn’t detonate like a bomb, but it did drop a valve.
Quite a painful experience nonetheless.
So, how did it happen?
I was cruising along the freeway one fine Sunday morning on my way to meet up with some friends for a nice ride to the countryside and some breakfast. I was going at about 70 miles per hour when I quick-shifted from third to fourth at about 6,000 rpm. Immediately, I heard a massive backfire, and the bike lost quite a bit of power. Thankfully, it didn’t stall, and I limped it to the nearest gas station to have a closer look.
It was immediately obvious that the engine wasn’t in good shape, as it had an odd rhythm when it idled, and there was a loud ticking noise—much louder than the usual Yamatick associated with these engines.
I knew right away that this thing was gonna have to come apart, and I’d have to order a bunch of parts for it, something that was surely going to take weeks, especially considering the scarcity of premium motorcycle parts in the Philippines.
A bit of context
Before I dive right into the nitty gritty of what happened, I think I need to share more about my bike. I’ve talked about it before in my long-term review, but quite a bit has changed since then.
It’s pretty far from stock, rocking the full Woolich Racing Race Tools package. Meaning it has a tune, a quick-shifter, a pit-limiter, and launch control. On the dyno, it pumped out about 80 horsepower, which was something I immediately felt after having it tuned.
And so, I couldn’t help but wonder if these modifications had something to do with the valve dropping.
The repair process
Now, I consider myself a fairly tech-savvy dude, but ripping into an engine is something that’s well above my pay grade. And so I decided to take the bike to Motorad Performance, a trusted repair shop that specializes in high-performance race bikes. After all, they did the tune and installed all the upgrades, so if there was someone who could get to the bottom of all this, it was them.
They immediately tore into the engine and discovered that one of the exhaust valves had dropped due to a failed cotter.
The cotter essentially locks the valve in place, and for some reason, it failed completely. The folks at Motorad decided to dig deeper to make sure that there wasn’t any other damage to the engine. They took the cylinder head apart, and luckily, the valve didn’t drop down low enough to come into contact with the piston.
Next came ordering the parts that needed replacing. Right there and then, I was sure that Yamaha Philippines wouldn’t have the parts in stock. And true enough, they didn’t.
I can’t really blame them, though, as bikes like the MT-07 are considered premium here in the Philippines, with just a couple dozen of them being sold every year, compared to the tens of thousands of scooters sold.
Indeed, premium bikes like this are just a drop in the bucket in Yamaha’s inventory, with scooters and commuters making up the vast majority. Plus, the fact that my bike was out of warranty didn’t put any pressure on them to find a way to source the parts for me quickly.
As such, my only recourse was to source the parts myself.
Luckily, the folks at Motorad provided me with a list of all the parts that needed changing. And so I headed over to Webike Japan to order all the parts I needed for the repair.
It took just four days for my order to be shipped from Japan all the way to Manila, and I immediately took the parts to Motorad to have them installed. And they did, just like that.
Back on the road, but questions linger in my mind.
With everything put back together, it was finally time for me to take my bike home.
In total, the whole fiasco took two weeks of riding away from me. The bike is now in perfect condition and even feels like it runs more smoothly than before the incident.
But the question remains: why did this happen?
I decided to consult the various FZ/MT-07 Facebook groups, and came across a startling discovery. As it would turn out, I wasn’t alone. There were a few other incidents wherein a quick-shifter resulted in valve damage specifically in the MT-07. One guy even had it happen to him twice.
But the technology behind a quick-shifter is pretty simple. It’s just an ignition cut that momentarily stops power delivery allowing the next gear to click in place—sort of like how you can clutchless shift by closing the throttle before shifting gears.
On top of all that, Yamaha’s engines are known to be extremely reliable, and the CP2 in particular is hailed as one of the most durable motorcycle engines out there. Of course, the upgrades I had installed were the main suspect, and I had the quick-shifter, launch control, and pit limited uninstalled.
I did, however, keep the ECU flash as the bike is running a full Akrapovic exhaust system.
As of this writing, I’ve already clocked in a thousand or so miles on the bike after the repair. It runs great, has lots of power, and is still really smooth. So maybe it really was the quick-shifter. But I’m still not 100% sold on the idea.
Maybe one of you has a guess as to what happened. If you think you know what’s up, feel free to sound off in the comments.
