Running lean

[quest]

Need advise, I have a 04 r1150rt. Took it in for the 6000 mile service.Got it back and it was hard starting,had to choke even in hot wheather,would stall sometimes at traffic lights,would have to lock the thottle to let it warm up because it would not idle when cold even on hi idle.I done this one morningand left the bike to make a call after about five minutes I came back to the garage and smelled plastic,look around the bike and the right exhaust pipe was red hot but not the left.Took it back to the dealer and they said they found a mouse nest in the air cleaner and that caused the lean mixture.I think they are trying to cover their butt because someone screwed up in the first place.I dont know much about the fuel injection system but if you restrict the air flow on a carburator you cause a rich mixture. Help!!!

[Wooster]

Hi quest (are you phone service ? oh no, that's Q West),

 

Sorry to hear of your problem. From symptoms, it sounds like too lean a mixture (hard starting, easy stalling, fast idle lever needed even when motor is hot), though I agree with your conundrum, i.e., restricted air passage should result in too rich a mix. On the other hand, what with motronic computer and all, I'm not able to discount trained mechanic's "too lean" call (and your symptoms seem to support lean finding).

How's your bike now ? With mouse house out of air filter, is bike running well ?

Lastly, while I feel your pain (melted plastic isn't pretty), letting these bikes warm up for anything more than half minute usually gets pipes (both) glowing w/melted plastic.

 

Wooster

 

BTW, Welcome to the club: perhaps others can offer coping strategy for plastic repair

[quest]

Why was it only on one side?

[Ken H.]

IMHO they're "covering their butt." It would be almost impossible to restrict the intake that much, and it would effect both sides, and it wouldn't effect the operation of the fast idle lever. They blew the throttle body sync. and cable setup the first time, plain and simple.

 

BTW, as you have apparently discovered, letting an RT sit on fast idle is a big no-no. You will melt plastic. Or worse. Start it on high idle, ride away conservatively right away, and as the bike warms kick off fast idle.

[Larsen]

I would take a look at the color of the spark plugs first. If one side has a very light color vs a mid grayish brown on the other side you'll know that the side with the light color is the lean side.

 

For this engine to run lean on one cylinder it would require an intake air leak between the throttle body and the cylinder head, or a restricted fuel injector nozzle. I would do a flow amount and flow pattern test on both injectors. The air leak could be as simple as a loose clamp or the o-ring seal was damaged upon installation or is missing.

 

In as much as this is a new or near new machine your dealer should be able to do these tests but then again if they think that a clogged intake would cause a lean condition then they, and then you, have bigger problems. There are many people masqerading as mechanics in many dealerships!