Power loss after valve clearance adjustment/CT installation???

[twinrider]

My shop recently checked and adjusted my valve clearances, installed the new cam chain tensioner and synched the throttle bodies. I got back the bike and mainly commuted since then but noticed that the bike seemed to have more vibrations through the handlebars, fuel economy was down and it didn't feel like it pulled as hard on the highway. Also had a bit more back firing on deceleration.

I took it to the dyno shop where I had the bike dynoed previously before and after installing the Arrow headers and PCV. They dynoed the bike again, verified that the PCV was working, and found that the bike was down about 10 hp compared to my last runs in April.

I am pretty sure this had something to do with the work I had my shop do recently, and would like them to double check what they did to make sure everything is how it should be.

But before I go there, can anyone think of anything they could have done that would cause the symptoms I described (more vibrations, worse fuel economy, less power especially in the upper end of the RPM scale)? :ear

Also wondering, do they have to remove the airbox to pull the cams and adjust the valve clearances?

Thanks for any feedback....

 

[whisperquiet]

I would think that the camshaft timing is incorrect and needs to be re-timed.

 

[tubebender]

Agree with above. Maybe off by 1 tooth.

 

[OldRider]

Text book example of the cam timing off.

 

[twinrider]

Thanks for the input, I will mention that to the mechanic when I go there today.

 

[greg the pole]

the tenere is very finicky with timing. If they didn't install the cams back correctly, the intake is proably off a tooth, and giving you grief.

 

[avc8130]

Thanks for the input, I will mention that to the mechanic when I go there today.

Let us know what he says/finds.

ac

 

[Don in Lodi]

::026:: timing.

 

[avc8130]

Any change in the vibration of the bike?

Any updates?

ac

 

[!kid]

If the cam was off a tooth wouldn't the cam position sensor see this, and give a check engine light?

 

[Z06]

If the cam was off a tooth wouldn't the cam position sensor see this, and give a check engine light?

If there is one it is reading off of crankshaft and would assume marks are aligned. Wouldn't read each cam for proper timing.

 

[avc8130]

Yeah. No cam position sensor on this bike. Just crank position sensor located at the bottom of the cam drive. No way to see messed up timing.

 

[fredz43]

It has happened to others that when the cam caps were tightened the chain jumped a tooth. I saw the result in our dealer's shop. The bike would crank, but not start. No codes or check engine lights.

 

[greg the pole]

It has happened to others that when the cam caps were tightened the chain jumped a tooth. I saw the result in our dealer's shop. The bike would crank, but not start. No codes or check engine lights.

tie wraps are your friend

 

[twinrider]

Any change in the vibration of the bike?

Any updates?

ac

I dropped off the bike on Sunday evening. The guy told me that the timing marks are supposed to be checked from the right side of the bike but that I had too many accessory wires under the rightside cover so he checked it from the left using a mirror. Needless to say I won't be using them again.... :

I asked him to recheck the timing and everything else he did if that turns out not to be the problem. Waiting to hear back from him...

 

[avc8130]

I dropped off the bike on Sunday evening. The guy told me that the timing marks are supposed to be checked from the right side of the bike but that I had too many accessory wires under the rightside cover so he checked it from the left using a mirror. Needless to say I won't be using them again.... :

I asked him to recheck the timing and everything else he did if that turns out not to be the problem. Waiting to hear back from him...

The timing marks aren't visible without a mirror regardless of your "accessory wiring".

Yamaha has punch marks on the cams that should line up also.

ac

 

[twinrider]

Yamaha has punch marks on the cams that should line up also.

ac

Thanks for that info, hopefully he is aware of that.

 

[avc8130]

Verdict?

ac

 

[twinrider]

Still waiting for a call back. I told him no rush thinking a few days is ok, but he's stretching it at more than a week...

 

[bloodline]

The timing marks aren't visible without a mirror regardless of your "accessory wiring".

Yamaha has punch marks on the cams that should line up also.

ac

Not exactly true. Take the bolts out of the electrical "tray" and it moves away just enough to see the marks on both cams and aids tremendously in checking your gasket upon replacement of the valve cover.