Problem after checking the valve clearance

[popsicle_3000]

So I pulled apart my 2005 bike to check the valve clearance the other day (bike has 68 000 kms) and everything was fine.
I put everything back together but now there is a problem.
bike starts up great/warms up, revs easily to redline.

But, on the road, there is a serious loss in power.
on both fz6's i've owned, there is a point where twisting the throttle more only seems to slow the engine down a bit (slighthly before WOT), but now that point is much earlier (1/2 of WOT).

even at half throttle there is a huge loss in power.
accompanying that is a change in engine/exhaust (don't know which) around 3-5000 rpm. it sounds a lot fuller, and deep. more of a rumble.
the whole engine seems bogged down, if you know what i mean.

-only thing i fiddled with while doing this service was the throttle free play. I tightened it up a lot cuz the throttle was loose.

My question is: could my symptoms be explained from overtightening the throttle cables? ie by tightening both cables i'm getting rid of the slack throttle but at the same time not opening up the butterflies enough so starving the engine of air?

i checked the butterflies valves when i adjusted the throttle and they closed and opened properly (it seemed)
thx

 

[Dave in Houston]

I'm far from an expert, but I've read posts on another bulletin board suggesting that the fuel line could be kinked, so that it will run fine under no load, but be short of fuel when trying to accelerate. That suggestion seems plausible to me.

Perhaps the experts will also chime in.

 

[1/2%normal]

you either over tightned the valves or theyre too loose. its real easy to do that if youre not careful. check them again and check the fuel lines, vent lines, fuel flow/pressure, oil pressure and and air filter. might have something in your fuel line causing your fule injectors to clog or not keep up with your throttle per say. And yes it could be that you over tightned your cables, just loosen them up slightly and try again. leave a little slack in them anyway just to be safe

 

[SovietRobot]

Assuming you didn't touch the valves and just checked them, first step would be adjusting throttle cable free play(things don't like to be tight on these bikes) to factory spec. Second would be checking fuel supply and vent lines.

Also did you remove any vacuum lines from the throttle bodies?

 

[popsicle_3000]

i didn't adjust the valves in any way. fuel line isn't kinked, airbox is fine. i'll readjust the throttle cables and see what happens, but i highly suspect it's that.
not sure what the vacuum lines are on the throttle bodies, but i dont think i took anything off them

 

[TownsendsFJR1300]

Go back and re-check everywhere you've been (including battery cables). Somethings been left unplugged or a vacuum line left unattached/bumped off, especially the air box as there's several lines there. The deeper sound would possibly come from a new opening (something not re-installed) in the air box.

+1 on the vent line line getting kinked. MAKE SURE ITS NOT KINKED, that'll cause weird problems...

A tighter throttle cable will not cause the problems you describe, but do adjust it to spec's (I do have all the play adjusted out of mine (and the FJR), as long as the throttle closees fully whith the wheel straight and lock to lock) Adjust the pull cable first, the return cable last.

Also, did you pull the gas tank off completely?

 

[popsicle_3000]

yeah i pulled it completely off.
which is the vent line?

 

[TownsendsFJR1300]

yeah i pulled it completely off.
which is the vent line?

The fuel tank vent line runs to the underneath of the gas tank, at the higher end, near the cap. The rubber line runs down and exits on the right side of the bike just behind the right foot peg..

 

[popsicle_3000]

it's fixed now. fuel or vent lines weren't kinked, and everything was connected. although i don't think the airbox was making a good seal w/ the throttle bodies. it's on solid now
wouldn't that be a reason for what i was experiencing?

 

[TownsendsFJR1300]

it's fixed now. fuel or vent lines weren't kinked, and everything was connected. although i don't think the airbox was making a good seal w/ the throttle bodies. it's on solid now
wouldn't that be a reason for what i was experiencing?

Obviously it did. Congrates you found it and thanks for the notification..

There are a bunch of vacuum lines running to the air box, with the box not fully seated didn't help any. Also, with the box not fully seated, the engine is basically (to some extent) running without an air filter leaning up the mixture some.

I put a very little bit of grease on most intake rubbers (and air filter rubbers when re-installing carbs, FI bodies, etc). It helps slip them back on, (especially the jap v twins when the carbs are super tight going in a small hole thru the frame where you have to twist and turn them, then get them seated).