power valve rattle not chain slap

[MattR]

Originally Posted by GMP

I have some pics I took when I had my side cover off recently, I'll try and post them later.

This would be good to have. Can you provide some instructions on how to adjust the belcrank (when you post pics)?

[rpduc]

4mm sounds like a lot of clearance between the flap and drum sides.

I'll bet I have close to that in combined end play from left and right. I did not have the #39 washer in there. Estanka found out earlier in the thread that in his case adding that "missing" washer spec'd from the parts list bound his flapper when open.

I get what you're saying about the preload on the actuator rod Glen. On mine the actuator plate rests against the stop with engine off, but I would characterize the "preload" as very very slight. I could envision it rattling with that slight pressure against the stop.

I just fired her up for a heat cycle after a new top end. I will pull the right cover and see what's going on in there when running. Is it just a "feel" thing when setting that preload or is there some "scientific" method?

[GMP]

Yes, just a slight preload by feel. The force is the governer spring acting on the rest of the system. This is not a documented procedure, just something I thought was a logical way to fix my '03 that did not appear correct.

Sorry guys, too much kids sports stuff to mess with photos tonight. I will try to do it this weekend though.

[BULTACOBRIS]

Update,
After a closer check it turned out that with the 8X16X1.5 mm washer,
the PV vas binding half way in its travel.
There was NO way i could make my PV work properly with the washer in place. It felt realy good with some play in the closed position, but it would bind half way.

My conclusion is that the washer is machined in to the PV, it certanly looks that way, and the parts list needs an update.

My 08 EC300 also had slop - a washer was placed between the bearings - and no binding happening (told the guy that did it about #39 missing - he didn't notice, but thought it needed shimming, so did the above)

[Noel]

Originally Posted by GMP

Yes, just a slight preload by feel. The force is the governer spring acting on the rest of the system. This is not a documented procedure, just something I thought was a logical way to fix my '03 that did not appear correct.

Sorry guys, too much kids sports stuff to mess with photos tonight. I will try to do it this weekend though.

Hi Guy’s

Reassembled cylinder and PV assembly and noted that with the engine off the exhaust valve bracket (part#35) was not resting against stopper bolt (part #33). The gap between both is about 5 mm, then in lifting the stick lever rod (part #1) it is evident that no preload is on the stick lever, thus allowing the stick and the bracket plate to move freely back and forth and hit the stopper bolt Part #33-

Is this my dreaded rattle I hope so.

So, how do I adjust the PV assembly to put some preloaded on the stick / valve bracket to reduce the possibility of the bracket moving back & forth hitting the stopper bolt.

This rattle is doing my head, not to mention my wife is frustrated with me obsessing with my bike- again.

Refer photo:

ttp://picasaweb.google.com/hoff49/MyPictures?feat=directlink

[GMP]

Noel,

You have one of two problems, both require removal of the side cover. After the oil, coolant is drained and the cover is removed, you need to verify that the PV governer balls are not displaced and jammed, as this will prevent the PV from closing. This is usually caused by pulling on the actuator rod with the engine off, manually moving the governer and allowing the ball(s) to fall out of position. If this is the case you can manipulate the governer to reseat the balls.

If the governer is OK, then the position of lever #6 on lever axel #4 must be adjusted. Loosen setscrew #5, fix or hold the actuator plate to the stop bolt, and while pushing the governer assy straight into the case with a grip that will put just a slight preload on the governer spring, tighten setscrew #5. Its eaiser to jam the actuator plate against the stop with something unless you have a helper to hold it there. Its obvious when you have the side cover off. The idea is to provide just a slight preload (closed) to the mecanism by the governer spring. You may have to do it a couple times to get it right.

I'm sorry about no photos, but this PC has some USB system issues and my thumbdrive with the photos takes a very long time to be seen by the system.

[rpduc]

O.K. for future reference here's a report on my "rattle."

I rode the bike for about three hours yesterday and did not produce the rattle. Previous to the top end job it occurred regularly when pulling hard at low rpm. Must have been piston slap like someone else reported a while back. Cyl. replated, new top end = no more rattle in those "lugging" situations.

I did not put the "missing washer" in. (#39) I still have a lot of end play in the PV assembly. I wanted to think it was the PV because that would have been easier and cheaper, but it obviously was not. I couldn't quite envision how too much end play could cause a rattle like I was hearing, but that optimism...

I can definitely see that a misadjusted actuator rod like Noel has could do it.

[BULTACOBRIS]

So how much rattle is too much?
This is my first modern 2 stroke - at low to mid revs mine sounds like a chain slipping over a cog (not loud though)
Is this the norm please?

[Noel]

Hi Guy's
Pulled off side cover to review the balls in the PV governor, I can see the balls only at the lower part of the governor, does this mean they have fallen out of position, if they have does this mean I have to disassemble the governor to reposition them or can I reposition them by laying the bike on it's side then pushing the governor inward then manipulating the balls into the correct position.

Need to get this sorted, didn't ride on the weekend, we had plenty of rain this week in the land of OZ - perfect for the Gaser

[rpduc]

So how much rattle is too much?
This is my first modern 2 stroke - at low to mid revs mine sounds like a chain slipping over a cog (not loud though)
Is this the norm please?

Very difficult to quantify over the internet. I was in the same position last summer, new to modern two strokes and used bike with a rattle that just did not sound "right" to me. I rode it for the summer hoping it was one of the "normal" rattles people here described but it seemed to get progressively worse. This winter I had it out on the ice few times and decided something was not right. Seems to have been piston slap in my case but I'd think that unlikely on a '08 300 unless it's been ridden a lot.

In my case the rattle was more consistent when pulling down low than the rattles others described as more intermittent or occasional and attributed to chain slap, PV etc.

Sorry haven't delved into the PV govenor.