rough at idle and constant throttle

[Burns1]

Ok so, 2008 with 31k miles. It has recently started idling really roughly and also when holding a constant throttle setting. Turn the throttle and she still goes well. I've tried to search threads and so far see ... battery (new 2k miles ago), TBS (no sync tool), tps sensor, injectors and plugs. I'm sure there are more possibilities out there though. So what is my recommended course of action here? Oh and I'm a broke ******* that's trying to save for a ride to Vegas in three weeks(that I was just informed of). Got a service manual and the tools. And basic know how. I've just haven't torn into this bike yet. Just basic maintainence. Ready for any and all suggestions and ideas. Thanks guys.

Burns1

 

[bluesdog]

If you just replaced the battery you may want to check that the terminal connections are clean and tight.

Sudden onset of rough idle/constant throttle may also be due to some bad fuel, so a good dose of seafoam or yammy ring free may be indicated.

Injector may be partially plugged, but typically that'll cause poor throttle response as well as erratic idle

A fouled or worn plug, or loose plug wire will also typically cause poor running and lousy throttle response.

That's all I can think of at the moment, but I'll bet someone else will be along soon to offer more suggestions

Hopefully there's a fellow forumite not far from you who'll be willing to lend a hand to help you get it sorted.

Good luck

 

[JamesK]

I'd also confirm there are not vacuum leaks, as that's something that would only be a noticeable issue at low RPM/idle.

 

[Mihalis fjr]

I would do a TBS firstly..I don't think that the problem is in the spark plugs or in the injectors..

Also a video could help..

 

[Wemi]

I would do a TBS firstly..I don't think that the problem is in the spark plugs or in the injectors..Also a video could help..

Video of what? TBS video is on UTube....

 

[Mihalis fjr]

I would do a TBS firstly..I don't think that the problem is in the spark plugs or in the injectors..

Also a video could help..

Video of what? TBS video is on UTube....

Video how his engine sounds..

 

[Intech]

Did the symptoms start right after a fill up? Was the last fill up at a station you don't use regularly or never before. If you answered yes to any of those questions I would go with bad fuel. Either way, a seafoam treatment wouldn't hurt. Doing a TBS after that wouldn't hurt either. You will at least have the tank off and do a thorough inspection of the throttle body area.

 

[TownsendsFJR1300]

Were the valve clearances checked at approx 26,000 miles?

A tight valve would make it run crappy.

If you have access to a lazer temp gun, shooting it at each header close to the head may help pinpoint down a cylinder (if one is much cooler than the rest)

A TBS, if it hasn't been done since new, would be a very good idea. I'd strongly suggest you but the tool and do it yourself, (its cheaper than Yamaha doing it) and you know before and after. (I have the Morgan Carbtune which has paid for itself many times over)

 

[Burns1]

Well now, don't I feel like a *****. Finally got around to checking the battery connections and, sure as sh*t, the negative screw had come completely loose and the cable end was basically just sitting on top of the terminal. Amazing how smoothly it runs when everything is tight. Could someone please send me my ******* patch? Sure hope I didn't just damage a fairly new battery in any way.

Burns1

 

[TownsendsFJR1300]

Your not the first.

Also watch for that red cap (on the positive terminal) accidentally getting stuck between the cable and battery...

Just as a side note, I had to recently replace my battery. I put just a touch of red loctite on the battery to cable bolts, just for insurance.

 

[NightShine]

Also watch for that red cap (on the positive terminal) accidentally getting stuck between the cable and battery...

Or changing out your car battery in the dark, not realizing that the new battery your buddy just purchased for you has black protective plastic caps over the lugs.

 

[CrabbyJack]

Or putting the battery in backwards and hooking it up...