Yamaha YZF-R7 Forum banner

R7 help

1266 Views 14 Replies 5 Participants Last post by  tranvannghia16041994
Hello, everyone.
Today my engine blew up on the highway.
I was riding in 6th gear when my check engine light started blinking, oil light came on and the bike started rapidly loosing speed.
I pulled over immediately, shut off the engine, called a tow truck.

I turned the bike on one more time on the side of the road to see if it would start.
It's clearly running on one cylinder, smoking out of the exhaust and smells like oil, I will attach a video.

What do you hear from the video, any ideas?
Is the motor totally blown, what could be the issue?
Blown piston rings, injectors, vacuum problem maybe?
  • Wow
Reactions: 2
1 - 15 of 15 Posts
When I turned it on, there was no check engine and oil light present.
Also I checked the oil level, it was ok.
No wheelies done on the bike, not even once.
  • Wow
Reactions: 1
I don't have any valuable answer for why it's blown but seems weird that you got it tuned and then 2 days later the motor blows up.
I would not just let the tuner get away with this.
Is it a well known tuner or some garage starter?
Something definitely ain’t right, I wouldn’t ride it anymore. I would check the plugs, I bet one of them will have oil on it. Highly doubtful anything the tuner did caused this. Unfortunately this sounds and looks like an engine tear down.
Might be worth taking the plugs out and sticking a camera in to have a look before you do anything too labour intensive. The state of the plug on the dead cylinder will likely give you a big clue: holed piston maybe?

Did you get a dyno printout with afr? If it ran OK on the Dyno with good AFR then maybe it went lean at the track due to something else which might explain the power on "rattle" you mentioned.
Something definitely ain’t right, I wouldn’t ride it anymore. I would check the plugs, I bet one of them will have oil on it. Highly doubtful anything the tuner did caused this. Unfortunately this sounds and looks like an engine tear down.
Of course, I'm not riding it anymore.
Might be worth taking the plugs out and sticking a camera in to have a look before you do anything too labour intensive. The state of the plug on the dead cylinder will likely give you a big clue: holed piston maybe?
I've heard some weird sound before, not touching it until dealer looks at it
My friends had the same sound as you, and they had a cylinder is totally blown.

I don't think you should activate the engine, to avoid more damage and take it to the engineer to take it apart and have it checked as quickly as possible.
My friends had the same sound as you, and they had a cylinder is totally blown.

I don't think you should activate the engine, to avoid more damage and take it to the engineer to take it apart and have it checked as quickly as possible.
Your friend also had the same engine?
What was the reason for its failure?
Well, the thing is your tuner tuned it. You reported a power on rattle to said tuner who assured you it was OK. Then the motor went pop......🤔

Was it actually tuned or was a generic r7 map just plonked on? I say that because isn't the restricted version actually a slightly different motor? Isn't it a 640? Dunno how much of a difference that would make.
Your friend also had the same engine?
What was the reason for its failure?
unknown reasons, maybe engine age is a time to need maintenance
1 - 15 of 15 Posts
Top