Camshaft off, maybe?

[Theycallmecrash]

Been riding around a lightning i just did the engine in, and it runs awesome. I get on my firebolt, and its a pig...

Is this front exhaust cam off a tooth? Almost seems like the marking is off. Im wondering if my firebolt is down on power cause a cam is off.

 

[jetlee]

The first time I installed the XB cams in my Blast, I had the same cam off by a tooth (retarded). If I gave it too much throttle at low/mid RPMs, it cut-out and popped like mad, to the point it was almost un-rideable.

I'd be cautious messing with the cams in the XB due to the tighter piston/valve clearances. I had quite a bit of room in my Blast motor that I didn't smack anything...I'd be afraid of smashing a valve in my XB9.

You could always pull the cams and change it, then rotate it carefully by hand a couple times and see how it looks. Though I think it's probably correct as it is. Keep in mind there's fewer teeth on that exhaust cam, so one tooth of the exhaust cam will move that mark further than one tooth on the intake.

IIRC, changing the exhaust cam one tooth is somewhere like 26° and the intake cam is 15°.

You also have to remember that the piston is chasing the exhaust valve closed. If it turns out that it's correct as is, then you set it back 26°...well, you can pull your own conclusions.

That's just my $.02, it's your engine.

 

[Sirius815]

Have you check the static timing on the firebolt? Your spark may be off by a little.

 

[Theycallmecrash]

Its a 2008 so static timing isnt the issue. I dont think I did but i may have swapped the push rods, i was pretty sure i put them in the right spots. The cams look good to me, im starting to run out of ideas why my bike is so down on power, runs fine, idles fine, just weak.

 

[Sirius815]

I'm assuming the gearing in both is the same..I know, I know, silly question, but as you pointed out, out of ideas.

Are the fuel and timing maps in the bikes the same?

 

[Theycallmecrash]

the 08 firebolt is geared more aggressive, but wont even bring the front up in first anymore. the 07 will float 2nd gear to noon. the tuning and maps are different just cause of the generation. currently stock maps in both, this power loss happened after a rebuild do to transmission failure. i initially thought the power was down cause it was breaking in, new rings and deglazed cylinders, compression is 155psi dead even between the 2. new spark plugs new wires, its not misfiring, I havent checked fuel pressure but my AFV indicates its rich not lean, and the O2 is brand new.

 

[Theycallmecrash]

Today i pulled everything apart moved that exhaust cam one tooth, everything lined ip perfect put it back together and its never felt so good, between the gearing and revived power, wheelies easy in second!

 

[ReadyXB]

 

[jetlee]

Awesome, nice to hear!

 

[EricZ]

Glad you got it figured out!

 

[thrstrmech]

[up] glad to hear you got it back to her old self

choices...now which to ride, the Lightning, the Firebolt or the half Buell

 

[Theycallmecrash]

Or the cyclone!