Power Valves Installed Backwards?

[jgw50]

So, i've been through this before, and i'm 99% sure that I am doing it right, BUT my machine is running like I put my powervalves in backwards.

Can someone give me their explaination of which direction the valves are supposed to go in?

Also, adjustment specs for an 07 M8 would be great as well.

 

[ARICH]

Beveled side down

 

[Frostbite]

Great, now you have me wondering if I put them in correctly on my 09 M8?

 

[89sandman]

seems theres a tab on them so they can only be put in one way...

 

[Frostbite]

I hope so but, it was my first time installing the after they were modified as part of the porting process and the manual just wasn't specific enough for a nimrod like me.

I printed the pages of the manual discussing the powervalves.

 

[W A O]

Power valves

I think if you put the power valves in backwards they will hit the pistons and would have already hurt the motor frostbite so if you have riden it and rode it hard and no problems you should be good.

 

[W A O]

Beveled side down

Yes and if you look at the way the pistons lay verses the valve the bevel is there so it cant hit the pistons. The other way and the sharp edge would hang down lower and hit.

 

[tatorsalad]

They wont hit the pistons on the cat and the way i would say it is the larger of the two bevels goes towards the head or piston

 

[Frostbite]

Ok, I'm confused.

So Mr. Tator Salad you say "the larger of the two bevels goes towards the head or piston".

That generates a question for me. The head is up and the piston is down, which is it please?

I will verify tomorrow.

 

[RKT]

They wont hit the pistons on the cat and the way i would say it is the larger of the two bevels goes towards the head or piston

Actually the larger of the 2 bevels goes towards the belly pan.. On the M7, this is a very common problem where the valves get installed upside down and then they never completely open.. bevel down.. flat/sharp towards the piston.

Tatorsalad is correct that they will not hit the piston if installed upside down.. but full power will NEVER be reached if they are in upside down

Having said all that... the m8 and M8 will not allow for the valves to be installed upside down.. but the M7 does allow for this to happen..

hope this helps

Kelsey

 

[jgw50]

Awesome Kelsey! I must have installed them correctly as everything went together fine and I also know that I installed them "short bevel" towards the piston. I had an M7 before this and knew it was an issue, and thought I knew how it was supposed to go (I did) but was second guessing myself.

Turns out however, my powervalve servo motor is not engaging at all. I can turn it by hand, and the valves are not stuck, but the servomotor does not cycle on start up.

I took my tank off and inspected all of the wires underneath. No wires were worn at all.

Now I guess I gotta figure out if the motor is getting a signal, or if I have other problems.

 

[RKT]

Awesome Kelsey! I must have installed them correctly as everything went together fine and I also know that I installed them "short bevel" towards the piston. I had an M7 before this and knew it was an issue, and thought I knew how it was supposed to go (I did) but was second guessing myself.

Turns out however, my powervalve servo motor is not engaging at all. I can turn it by hand, and the valves are not stuck, but the servomotor does not cycle on start up.

I took my tank off and inspected all of the wires underneath. No wires were worn at all.

Now I guess I gotta figure out if the motor is getting a signal, or if I have other problems.

The M servos do not cycle like the old 900 Cats.. so, you can not check like that..

Best way to check them is to simply put the sled on a track stand or pull the belt and rev the engine above 7000 and see if the servo actuates

 

[Frostbite]

Kelsey, I have to say you have been a tremendous amount of help today!

Thank you very much!

 

[Frostbite]

Here's a little power valve information from the 2009 Cat manual

NOTE: The servo will activate once at APV cycle
RPM. If the servo cycles three times, cable length
adjustment or valve inspection is required.

NOTE: The 800 cc and 1000 cc have a three-stage
exhaust valve system. The stages are closed, midopen,
and full-open. Each model has a designated
RPM at which the system is synchronized and
checked by the ECU for proper operation occuring
once each time the engine is started.

The 800 cc system is checked at 4800 RPM and the 1000 cc
system is checked at 6100 RPM (Crossfire/FSeries)
or at 6270 RPM (M-Series).


ENGINE VALVE POSITION CYCLE RPM

600 cc Full-Open 73-7400 (Low/High Alt)

800 cc Mid-Open 60-6500 (Low/High Alt)

Full-Open 78-8100 (Low/High Alt)

1000 cc Mid-Open 6300 (Low/High Alt)

1000cc Full-Open 6500 (Low/High Alt)

APV CABLE LENGTH

ENGINE CENTER ± 0.039 in.

600 cc 1.417 in.
800 cc 1.377 in.
1000 cc 1.319 in.

 

[idareyou]

This link has the best explanation I have found. Laydown motor (700cc) is on pages 8-9.


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