Yamaha R1 Forum: YZF-R1 Forums banner

1 - 20 of 677 Posts

·
Save a life, grope your wife!
Joined
·
1,514 Posts
Discussion Starter #1
Today I started to do some adjustments to the bike. I started with the EXUP. I greased and adjusted it and it was fine. I took it for a brief spin and it was acting worse than it had been (see this thread: http://www.r1-forum.com/forums/showthread.php?t=233205). I am certain that it is clearly missing a cylinder in the lower RPM's. I took the bike back to the garage and let it cool. I restarted and checked each header pipe. All heated up quickly except #4. I decided to tear it down to check the plugs and wires. Upon removing the air box cover, I noticed that the cover above the #4 intake was wet with fuel. I finished removing the air box and restarted the bike. Idle was still rough, but then I noticed something else. When I gave the throttle a quick blip, there was some fuel blow back from the #4 intake.

I should also mention at this point that the bike starts a little harder than usual. It has always started with the first press of the button, but now it takes two or three tries.

I am going to pull plugs and check them, also going to check the coils (although I should get an error code if any coil was bad). I guess I will have to tear into the head and check valves and springs as a last resort. This really sucks with the bike being one month out of the warranty period.

I guess this would be an opportune time to put on the Graves AIS removal, eh?

So. does anyone have any clues as to what else may cause this condition?
 

·
Registered
Joined
·
701 Posts
Today I started to do some adjustments to the bike. I started with the EXUP. I greased and adjusted it and it was fine. I took it for a brief spin and it was acting worse than it had been (see this thread: http://www.r1-forum.com/forums/showthread.php?t=233205). I am certain that it is clearly missing a cylinder in the lower RPM's. I took the bike back to the garage and let it cool. I restarted and checked each header pipe. All heated up quickly except #4. I decided to tear it down to check the plugs and wires. Upon removing the air box cover, I noticed that the cover above the #4 intake was wet with fuel. I finished removing the air box and restarted the bike. Idle was still rough, but then I noticed something else. When I gave the throttle a quick blip, there was some fuel blow back from the #4 intake.

I should also mention at this point that the bike starts a little harder than usual. It has always started with the first press of the button, but now it takes two or three tries.

I am going to pull plugs and check them, also going to check the coils (although I should get an error code if any coil was bad). I guess I will have to tear into the head and check valves and springs as a last resort. This really sucks with the bike being one month out of the warranty period.

I guess this would be an opportune time to put on the Graves AIS removal, eh?

So. does anyone have any clues as to what else may cause this condition?
Sounds like its an intake valve problem....or firing on the wrong cylinder
 

·
Save a life, grope your wife!
Joined
·
1,514 Posts
Discussion Starter #4
Thanks guys. Been asking around at other sites and places. This seems to be the popular vote....unfortunately.
 

·
Save a life, grope your wife!
Joined
·
1,514 Posts
Discussion Starter #5
Talked to the service manager at the dealership and he thinks it's most definitely a valve train problem. He said since I was only a month out of the warranty period to call Yamaha and give it a go. They may cover it as a good will gesture. If not, I'll be dropping the engine out next week. I'm guessing a broken spring at the very least, which would be great at this point because it's only a $6 part, but then there is the head gasket that needs replaced. Ah, what fun.

I'll start taking some pics if anyone is interested. I guess I'll be doing that valve clearance check sooner than I thought.

Oh, and I ordered my Graves smog block off kit, along with a few other goodies. At least something good will come of all this!
 

·
Save a life, grope your wife!
Joined
·
1,514 Posts
Discussion Starter #6
A quick update...

I finally finished that R6 I was rebuilding, so now I have started tearing apart my R1.

I have the radiator dropped, exhaust off and throttle bodies off. Initial inspection down the #4 intake throat shows the left intake valve discolored at the top where it exits the valve guide. Looks like heat discoloration. Additionally, there looks to be small globs of metal around the valve seat. I can't tell yet if this is causing the valve to not seat thereby causing the blow back and loss of compression, but I will know more soon and will keep this thread updated.

I am posting this from work, but I have pics on my computer at home and will post some up when I can.
 

·
Save a life, grope your wife!
Joined
·
1,514 Posts
Discussion Starter #8
It was a friends 2006 R6S in Yamaha Team Blue. Still looks stock but in addition to tearing down and rebuilding the motor (clutch blew up) we installed Speedbleeders, flushed brake lines, changed fork fluid, installed a Driven 520 conversion kit with -1/+2 sprockets, and installed a Graves block-off kit.

I can never seem to find time to upload pics.
 

·
add it to my tab officer!
Joined
·
1,791 Posts
that sux dude, im in new zealand my bike has two years unlimited ks. warrenty
 

·
Save a life, grope your wife!
Joined
·
1,514 Posts
Discussion Starter #10
Nice. I think if I end up trading for an 09 I will opt for the extended warranty.
 

·
Save a life, grope your wife!
Joined
·
1,514 Posts
Discussion Starter #13
I wish I could have gotten better pics down the intake so you all could see the discolored valve stem and deposits down near the valve seat, but this is the best I could get with my camera. The valve with discoloration is actually the left one.

I hope to get better pics once the engine is dropped and the head is off.
 

Attachments

·
Save a life, grope your wife!
Joined
·
1,514 Posts
Discussion Starter #16
I found the problem...not good at all!

Looks like the valve guide wallowed out and allowed the valve to wear away at the seat. What a ****in' mess. I will be taking the head down to the dealership this week and also contacting Yamaha about possibly replacing the head. That's alot of money I'm gonna have to shell out if they won't deal with me. At least there is no piston damage.
 

Attachments

·
President Elect
Joined
·
1,904 Posts
yes ... the cylinder on the right looks different.. more carbon deposits...if valve guides are wallered then cylinder head replacement is a must...
 

·
Save a life, grope your wife!
Joined
·
1,514 Posts
Discussion Starter #18 (Edited)
I'm pretty sure the carbon deposits are a result of the incomplete seating of the valve and loss of compression. That valve actually wore away at some of the combustion chamber dome. They'll probably say I over revved it or some shite!
 

·
burnin' up the streets
Joined
·
8,786 Posts
just put a new guide in it, get a valve job & you're good to go!

that is if yamaha won't help you out.
 

·
Save a life, grope your wife!
Joined
·
1,514 Posts
Discussion Starter #20 (Edited)
That will be my first avenue if Yamaha won't help. I will need to find a reputable shop capable of repairing and doing a 5 angle grind on the seats.
 
1 - 20 of 677 Posts
Top