Need help figuring out reason to power loss.
 

XT Newbie here, hello everybody! :)

I recently bought an XT660R 2006 with a lot of goodies already fitted. It has PC, Speedo healer, K&N filter and Metal Mule exhaust. Also a lot of acerbis goodies and small cosmetic mods.

The bike ran and is still running fine but something happened last week when riding home from work. I overtook a couple of cars when suddenly I felt a momentary loss of power and the sound from the bike was a bit different, a bit quieter. This happened during the overtake which made it a bit creepy.

Now it feels like I don't have 100% of the power I had before. Based on my butt dyno, there's like 90% left of what I had in the beginning. It runs OK, I can take it on the highway no problem but the peak power is missing.

Also, the final twist of the handle doesn't give the desired response. Is there something simple I should check, something that can shake loose or such? Thankful for any help! Cheers!

Does the bike have full throttle? Check the throttle body at full throttle.

Anything blocking the intake/snorkel side?

How is the packing in the exhaust anything blocking the exhaust internally?

Thanks for you help!

- It feels like the mechanical side of the throttle works since I can pick up speed when going full throttle, it just happens more slowly than before. There's like a "dead zone" near full throttle where the bike doesn't respond when I'm twisting it. How can I check the throttle body at full throttle? (Propably a dumb question but I'm a noob. :053:)

- I will check the intake side/snorkel tonight!

- I'll also check the exhaust packing but is it a packing that should be replaced every time or is it reusable?

Most exhaust packing needs to be changed every 2 years.

Open the throttle fully, then check the throttle body to make sure you have full throttle there.

Are there any fault codes logged in the dash?

I'll check, I just read the diag mode howto article and printed it to take home with me. :)

B-I-N-G-O and Bingo was his name! I found that a rag I kept under the saddle had been sucked onto the filter thus blocking the air flow. A user error in other words. :) I didn't know that the filter was situated right under the saddle, on my previous DS bike it was under the fuel tank (V-strom). I will not be storing anything under the saddle from now on...and by admitting this mistake I hope to serve as a warning to others! ;D Thanks for your kind help!

now thats a good result :)