650 Accelerates and Decelerates on its own

Hi, I've just gotten my first sport bike, which is the SV650. I haven't made any modifications, and I had it checked out by a mechanic before I purchased. Now, when I ride, the bike accelerates and decelerates on its own. It's usually like a long jerk, then it rides normal for a time, then it accelerates and decelerates again (I know it's not the best description). I'm still fairly new to the riding world, but I would appreciate any help I can get.

Thanks in advance

[Red Herring]

Hi, what year is the bike, is it a fuel injected or older carburetor model?

[Red ones]

And was it raining?

[maviczap]

Originally Posted by Red ones

And was it raining?

Sounds like wet front plug syndrome

Thanks for the responses. It's a 2008 and it is fuel injected.

Unfortunately it wasn't raining.

[maviczap]

Could still be wet front plug, did the engine noise change & did it feel like it was running on one cylinder.

How do I resolve the wet front plug issue? Is it as simple as getting it replaced?

Yeah when it does act like that it feels like I'm riding on one cylinder. With regard to the engine noise, I'm not entirely sure. I'm gonna ride it a little later today and I'll listen out.

[maviczap]

A quick fix is to spray some WD40 onto the spark plug to see if this cures it.

If this is the problem, then a front mudguard extender is required (Fenda extenda), plus some silicon grease round the plug cap & clear the drain hole on the right hand side of the front cylinder. Blow some air through it

[Red ones]

You could be losing a coil. There are two and they tend to slowly fail rather than just pack in.

mine did it when the accelerator cable had some play in it.