Yamaha R6 Forum: YZF-R6 Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #1 (Edited)
I have an 09 R6S that I purchased earlier this summer for cheap. Guy couldn't get it to start, but it turns out the TPS sensor was off. When I got the bike, he had just the it back from the shop whom I'm guessing did not have time to put everything back in place since he picked it up a few hours before i bought it. I was able to get everything back together(air box, new filter, changed spark plugs, oil change, coolant change), and it starts up pretty well. After it warms up, if i rev it to about 4k, the rpms shoot up to 6k and remain there. So far I've only been able to get them to drop by shutting off the bike. Any ideas? Maybe a vacuum leak? Also, the shop had just performed a valve adjustment, but stated they couldn't get the bike to start (they never cleared diag I'm guessing).
 

·
Registered
Joined
·
1,798 Posts
So it idles normal around 1750 until warm up and then won't return to normal idle after warm up. Idle probably constantly wonders by as much as 800RPM. After a valve adjustment, the manual instructs us to syncrohonize the throttle bodies. There is a "dial" to adjust idle level on the right side of the bike, just behind the fairing. It's in the "V" section of the engine between throttle body and trans. Warm engine vacuum readings should be 7 inches vacuum for cylinder three, and the rest should be adjusted to match cylinder three, per manual. Personal recommendation, bump up your octane before you attempt to make adjustments. Ran mine at well over twice the mileage for plug regap and never could get it to run right after heating up, until bumping the octane. Initially I used 1/5 of the Lucas Octane Booster bottle (containing MMT) and within a couple of tanks, started dialing it back and finding that I need less than 1/5 to get it idle and run right after warm up. I think too much octane makes it more difficult to cold start.
 

·
Registered
Joined
·
1,798 Posts
One thing I meant to mention but slipped my mind, there's an auto choke cylinder on the top-back of the throttle body. Verify that it's extending out when the bike is hot. It might take the cooling system a few hot/cold cycles to fully bleed. It should extend out regardless, but check just in case.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #6
It's currently set to idle around 1350. I've tried idling it up some, but when I do, it instantly shoots up to about 4-6k when I start it. I'll look into the auto choke once I get home today.
 

·
Registered
Joined
·
1,798 Posts
Link content quoted...
Sorry, we couldn’t find that page

Make sure you’ve typed the URL correctly, or try searching Vimeo. You could also watch one of the videos below instead.
 

·
Registered
Joined
·
1,798 Posts
Can't smell it or see the plugs, but ignition system on the outset, seems fine.

Twisting the throttle (increasing air) and it wants to stall. On a warm engine, this typically is either timing or fuel related.

You release the throttle (decreasing air) and it runs up the RPM. On a warm engine, vacuum leaks typically stall them.

In diag mode, your TPS is steady, stable and consistent? Have you checked the timing?
 
1 - 12 of 12 Posts
Top