"09 450R is acting up

[Jah.got.me]

It starts up just fine and idles normally, but when I give it throttle, the revs either hang high or sometimes slowly fall off and even die out. It didn't used to do this, ran strong about a year ago and this issue just gradually started. It's running a stock carb with an FMF slip on, nothing fancy. I'm thinking it might be a vacuum leak or maybe the throttle's sticking a bit. Would love to hear your thoughts.

 

[NoOneIsInnocent]

It starts up just fine and idles normally, but when I give it throttle, the revs either hang high or sometimes slowly fall off and even die out. It didn't used to do this, ran strong about a year ago and this issue just gradually started. It's running a stock carb with an FMF slip on, nothing fancy. I'm thinking it might be a vacuum leak or maybe the throttle's sticking a bit. Would love to hear your thoughts.

I bet it's the throttle. check it in case you need to change it

 

[RoadTested]

@Jah.got.me it can be the TPS or throttle cables, I think you need to check all of the problems that are possible

 

[NikiLabuda]

I'm thinking a vacuum leak. It can cause these symptoms and it's relatively easy to verify.

 

[JemP1990]

Older bike so check the carb boots for cracks or leaks, and make sure the throttle cable moves smoothly without sticking. Cleaning or adjusting the carb should help too, especially if it's been a while since service.

 

[afroguy13]

I'm thinking a vacuum leak. It can cause these symptoms and it's relatively easy to verify.

Right, it definitely sounds like a vacuum leak or possibly a sticking throttle slide or cable. Since it idles fine but hangs or dies with throttle, a leak could be letting in extra air, throwing off the fuel mix. .Check the intake boot for cracks, ensure all vacuum lines are secure, and make sure the throttle cable and slide are moving freely. Also, clean the carb thoroughly,, especially the slide, pilot jet and air screw, since buildup can cause similar symptoms

 

[Thelittlefriend]

I'm with @RoadTested on this. I've had a few machines where the cables would get stuck for some god only knows reason. Once you give it some gas, check to see if the tension on the cable remains normal or not. This could also be a problem with the flap. But I'm confused a bit about it cutting out. It does that all the time or occasionally?

 

[Jah.got.me]

I'm with @RoadTested on this. I've had a few machines where the cables would get stuck for some god only knows reason. Once you give it some gas, check to see if the tension on the cable remains normal or not. This could also be a problem with the flap. But I'm confused a bit about it cutting out. It does that all the time or occasionally?

Thanks so much to you all, I actually did check on that throttle after @RoadTested replied and as much as it was the culprit my brother also found that there was a vacuum leak, so I think its safe to say it was a little bit of both
Thanks to you all for your suggestions and I hope this thread comes in hand for someone