02 Yamaha R1 very odd running/idling problem - video included!

[A4R1]

Hey,


So I go to the grocery store to pick up some milk, everything is good with no problems at all. I go to start the bike and it sounds like it was misfiring with rough idle/rumbling then dies. Hmm, so I start the bike back up and it idles a bit better but still a bit rough. I managed to limp it home but on the way back it was cutting in and out like running perfectly fine and then super choppy and no power at all and I had to keep it revved higher so it wouldn't stall at the lights. I thought it was going to buck me off!!


Bike is a 2002 R1, all stock performance wise besides a basic slip-on.


Things I did so far:
-drained the gas tank and put new fuel with a tiny bit of injector cleaner and octane booster (thought I might have foul gas)
-took throttle bodies off, no leaks or anything unusual
-did resistance check of the TPS as per manual - good, within spec
-did resistance check on all the coil packs as per manual - good, within spec
-checked the plugs - all good, no discolouration or smell


Put everything back together and still get the same symptoms.


Here is what is happening ->http://youtu.be/mKwJyG2IpW4


As you can hear, idle is rough and chuggs. Slow throttle increase isn't too bad but it still sounds like a bit of misfiring. Fast blips of the throttle just want to make the bike stall and it makes a sound I've never heard before. Almost like the spark or fuel isn't keeping up with eachother and the RPMs just stay put and then it stalls out. No fault codes pop up which makes things even harder to figure out.


The worst part is that everything was perfect and bike was running like a dime as usual, then all of a sudden this happens!! Can anyone help me out??


Thanks in advance.

 

[Ed In Mississauga]

My guess would be a vacuum leak. Check any hoses and carefully check for any cracks in the rubber boots or perhaps one not seated properly.

 

[frekeyguy]

sounds like a cylinder isn't firing or the throttle bodies are out of sync. need to take things apart and dia.

Answer to your question: We can tell you what that 'crazy' noise it and fix your bike - but cannot over the inter-web. It will take some testing / figuring out see what the issue is.

 

[Iggy76]

I'll split the difference... idle sounds like only 3 cylinders, then when you are slapping the throttle it's dropping another one. I would guess air leak or fouled plug for the first part of the problem. You are probably due for a TB synch as well, which would definately contribute to the rough idle.

As stated above by freakyguy, you won't be able to fix this over the internet. Unless google has opened a service department I don't know about.

 

[A4R1]

My guess would be a vacuum leak. Check any hoses and carefully check for any cracks in the rubber boots or perhaps one not seated properly.

When I had the throttle bodies off I checked the hoses and connections and everything looked good. I'll take another look just in case, vacuum leaks are sometimes really tricky to find!

sounds like a cylinder isn't firing or the throttle bodies are out of sync. need to take things apart and dia.

Answer to your question: We can tell you what that 'crazy' noise it and fix your bike - but cannot over the inter-web. It will take some testing / figuring out see what the issue is.

I agree with the misfiring but I don't think the throttle bodies would just become that out of sync to go from running normally to this you know?

I know I just want to get some ideas and possible answers to be able to check them out before resorting to a shop or something. I'm starting to lean more towards something with the spark. I picked up some new iridium spark plugs this morning so I'll swap them in and eliminate one more possible thing.

I'll split the difference... idle sounds like only 3 cylinders, then when you are slapping the throttle it's dropping another one. I would guess air leak or fouled plug for the first part of the problem. You are probably due for a TB synch as well, which would definately contribute to the rough idle.

As stated above by freakyguy, you won't be able to fix this over the internet. Unless google has opened a service department I don't know about.

I'll check over the vacuum lines again and swap the plugs. The bike is around the kms for a sync so after I get all this figured out I'll prob take it in or get someone to help me sync them with the proper tools.

Thanks for the replies!! I know you can't fix it over the internet, duh lol but it's a great place to get ideas from, that's what it's for!

 

[A4R1]

Changed the plugs and all is back to normal!!! Super clean and smooth idle, great throttle response and no more stalling!

I can't believe fouled plugs would cause such symptoms! Thanks for all the replies and I hope this helps someone else out too! I totally skipped over the basics so now I know to step back and start from the basics and work my way through the system.

 

[Kuro]

Strange how it happened all of a sudden. I would have thought the symptoms been more gradual but good to know. Thanks for posting your solution. I was subbed to this thread to see what the resolution was.

 

[A4R1]

Strange how it happened all of a sudden. I would have thought the symptoms been more gradual but good to know. Thanks for posting your solution. I was subbed to this thread to see what the resolution was.

I know eh, that's what I couldn't figure out! There was no build up of symptoms like running rough or anything, I just go to start it that time and the spark plugs said NO MORE!! I did notice it got worse the longer I ran the bike and the more I gas it throttle....clue #1 I suppose!