[Noobster11]

Started having an issue with my 2008 Ninja 650r were i would be on the freeway, I'll drop a gear and accelerate but when i start accelerating the motorcycle just rocks back and forth until i ease off the throttle. Read that it can be issues with the chain, sprocket or spark plugs. I attached a picture of the front sprocket and spark plugs any help will do. THANKS!!!

 

[Ozninjaguy]

Hi. Welcome onboard. Maybe inspect the cush-drive in the rear wheel. If they are original they could have perished/shrunk allowing for some free-play of the rear sprocket hub.

 

[motocopter]

Welcome!

There seems to be a faulty ignition electrical connection somewhere that affects both cylinders that appears to manifest itself with vibration from higher engine rpm (your downshift). You could remove the fuel tank and verify connectors to the coil sticks. I'm not sure if the two connectors at the coil sticks are part of a "Y" mini harness or if their wires simply connect to the main electrical harness. Be sure connectors are fully connected.

On the right side of your engine is the pulse coil and harness. Follow it back from the right side crank shaft area to the connector---maybe about 15-18 inches of harness. Look closely at this connection.

Something else to consider is a good battery charge and functioning charge system. You need to see 14+ volts measured at the battery with a high idle speed.

Your spark plugs look new; so, that suggests they were replaced in trying to correct the problem.

 

[rcannon409]

Dirty fuel filter might act like that. Filters are dirt cheap, but if you can't do it yourself, it would be a few hundred.

I know ignition issues can act like this, but it sounds like that is good, until you are in a situation where you end more fuel?

Has the bike been sitting, or did this issue just start?

 

[JustAJ]

By "rocking back and forth" do you mean that the bike is surging? As in it's going forward and backward, or that you have acceleration and then you feel a loss of acceleration over and over in a rhythmic pattern? If so, the problem is most likely your chain has a tight spot and needs replacing. This is most noticeable at high RPMs. Make sure you replace the chain and both sprockets as a set.