power valve rattle not chain slap

[Noel]

Hi Guys

I pulled my power valve assemeble apart last night (07-250ec) and discovered a nut at the end on the LHS valve assembly. (I'm the 2nd owner). I havent seen this nut described or illistructed anywhere before, is this normal or has the previous owner done some modifications, note the keeper plate was installed as well.

Also is it normally possible to pull out the PV flapper valve out the exhaust opening, as I cant, I want to avoid removing the head and cylinder if possible.

[HydroDog]

Originally Posted by Noel

Also is it normally possible to pull out the PV flapper valve out the exhaust opening, as I cant, I want to avoid removing the head and cylinder if possible.

I'm not sure if the 250's are the same but on my 300 you lower the piston to bottom dead center, remove the flapper rods, push the flapper up on top of the piston and turn it sideways and pull it out the exhaust opening.

[rpduc]

It's unclear to me what you're describing there by "a nut at the end on the LHS valve assembly."

The only fastener inside my left hand cover and on the parts diagram is the socket head retention bolt and washer. (left hand while sitting on bike)

[gasser]

My 07ec250 has a slightly different left hand side power valve assembly than my older bikes have. The difference is the LHS assembly has a longer shaft that the 2 bearings fit on and the end of that shaft is threaded. My bike did not have any nut on the shaft.

[GMP]

That sounds something like the different drum valve that comes with the adjustable PV kit from France. Did you buy that bike used? My '07 is the same as my older bikes, the drum valve shaft is flush with the outer bearing.

[SpeedyManiac]

There shouldn't be a nut on the end of the LHS pv assembly. It is threaded, but no nut required. My 07 is like that.

[Noel]

Originally Posted by gasser

My 07ec250 has a slightly different left hand side power valve assembly than my older bikes have. The difference is the LHS assembly has a longer shaft that the 2 bearings fit on and the end of that shaft is threaded. My bike did not have any nut on the shaft.

Your right- however my bike has the nut which really dosen't do anything.
In a desperate attempt to rid my bike of this horrendous rattle I have installed new bearings and clean all parts. My concern is now it will rattle more, in reviewing the main PV flapper (part #30) you can see a gap of approx.4mm between the two PV assemblies (#31 & 40) thus giving you side -way slap, I was thinking about putting 2 x 1mm washers either side of the flapper to reduce the sideway movement / rattle of the flapper. What do you guys thinks. I read Glenn’s comment that you should get some rattle and I agree but my bike rattle is excessive..

[GMP]

Noel,

With the motor off, is your actuator plate resting against the stop bolt head with just a very slight preload? If not, this will cause more rattle at idle and low revs as the PV is never forced completely closed.

My bike is all buttoned up now, but if I have a spare PV gasket I'll pull the left side drum (easy) and take some measurements. It should be easy to determing the total clearance between the parts.

[Noel]

Originally Posted by GMP

Noel,

With the motor off, is your actuator plate resting against the stop bolt head with just a very slight preload? If not, this will cause more rattle at idle and low revs as the PV is never forced completely closed.

My bike is all buttoned up now, but if I have a spare PV gasket I'll pull the left side drum (easy) and take some measurements. It should be easy to determing the total clearance between the parts.

Hi Glen,
I havent put it back togther yet but I will check. Prior to reassembling I have tried to simulate what your talking about by putting some load on the actuator plate (by hand) then with my other hand move the flapper valve and it still has plenty of side way slack and about 1mm vertical slack, hence my thought about putting additional washers either side of the flapper, however this is not my preference, but I need to find a way to reduce/emilinate the rattle.

[GMP]

Noel,

The PV flap and left drum are moved by the rod from the right drum, and pivot on the other rod. There must be play here so it operates when fouled, this comes from the clearance fit of the rods in the drum holes, and the slot and pivot hole in the main flap. It adds up and their will be some rotational play in the right drum (actuator plate) when the other parts are retained. What I'm talking about is an adjustment of the belcrank under the sidecover. If adjusted correctly, some of this play is taken up until the PV starts to move, reducing the noise. If its loose, the valve flutters around partially open at idle. My '03 was more noisy than my '00 and '07 and this was the problem. I could hold the actuator plate down to the stop by hand with the engine running and reduce the noise. I have some pics I took when I had my side cover off recently, I'll try and post them later.

4mm sounds like a lot of clearance between the flap and drum sides. It would be nice to get some real measurements from a few bikes. This shouldn't be a wear issue as the parts are steel and have lasted for years.