Power Valve definatly adjustable !!!
 

For those of you who have been asking and wondering about the power valve timing adjustability , we have finally discovered what it takes.
We have been doing an on going search for the difference in power between an 06 DE 300 and a 08 EC 300. The 06 was bought used from a bank repo from a dealer. The 08 I bought new. We had the 08 before the 06 and when we got the 06 home and got it jetted for our altitude we realised it was a way different power delivery than the 08. We went for over a year trying to match port timing and compression only to make minor improvements to the 08. We finally realised that the rain sunshine switch was faulty and bipassed it at the CDI and that made a big difference but still didn't have the knarly off idle torque the 06 has. We started suspecting PV timing from our experience with KTM 300s. We ordered 2 sets of clutch cover gaskets along with water pump gaskets from Gofasters. We pulled the clutch side off of the 06 and discovered no shims behind the PV governor spring. This takes away preload and rate from the spring and allows it to open sooner and faster. We then pulled the side off the 08 and removed all the shims. The power delivery is now exactly like the 06.
The shims are very thin and we were apprehensive about whether removing them would make that much difference but it definatly worked.
As a side note there is pocedure that we discovered that works pretty well to disassemble the governor. Lay the bike over on its left side so the governor balls don't fall out all over the garage floor. When re-installing the governor balls, we just layed them in the cup and spun the cap until they all fell into their individual slots . It takes a little patients on this part and it helps to have a small ice pick to reach in and position some of the balls in there slots as you rotate the cap.
The main clutch side cover can also give fits to try and remove because it is tight dowled onto the side case. Be patient and try not to use a screw driver to pry it away from the main case. Re- installing is a little tricky also to get the gasket in place on the bottom.

Try and keep all the screws in their perspective holes because it will drive you crazy when you realise there are about 4 or 5 different lengths and some are so close to the same but just enough different that puting too long of screw in will result in a damaged thread or case !
It also helps to look at the parts break down on Gofasters sight or Gas Gas .com.
I wish I would have taken some photos to go along with all of this and if there is enough request maybe we will do it again. Hope this helps everyone.

Very interesting, thank you for the update. I suspected something like this. Did you measure the shims?

Genarally the longer bolts go where the dowels are.

Great job!! Persistence pays off in this instance. It's great to read when someone just sticks to a funky issue until they figure it out (like the guy from Australia with the 200 who eventually sent his motor to Holland to find out all the things wrong with it from new).

How many shims were there and yeah, what is the thickness of them?

More good "undocumented" info for GG riders. KTM sure makes it much easier with their setup though.

The GG power valve was never conceived to be user tunable, so ease of doing it was never a consideration. Measure the shims and check mcmaster.com, they have some metric shims.

Thanks 101, I will be pulling mine out tonight! Your persistance paid off !

You will be helping us GasGas riders to like our bikes even more, and
grow the popularity. :) :) :D

I put a tiny dab of grease in each of the races - enough to hold the impeller balls in place when I flipped the retainer back over.

Great info - once I get over the clacking, I may go back in and take the shims out.

I didn't measure the shims because I didn't really care at that point. The shims for each model year can be read on the parts break down on GasGas.com. They give the sizes on there. The longest bolt goes in the front water pump cover. I do agree that KTMs method is way user friendly. My opinion is that I have never been on a more user friendly motor in my life. I've been on worked over KTMs and have yet to match this combination of the GasGas. I'm not biased I tell black (no pun) and white. The 08 has an RB carb and it is working very well. I need to send it back in to RB for some minor adjustment on the pilot circuit but most of the time it is flawless.We are at 4000 ft of altitude and when the temp is hot it has a slight load up but very liveable. The 08 with this carb(bored to 39mm) revs higher than the 06 with the stock carb and the LTR jetting.

I left a little bit out on the first post but lack of knowing how to explain is the reason. The small bell crank shaft that transfers motion from the PV governor to the rod going up to the PV is the subject. There is a small lever that bolts to the front of the shaft that can be removed to free up the pin behind the governor to allow removal of the governor assembly. It is attatched with a small lock nut. The lever is indexed to the shaft so its a no brainer to remove and re-install. There is no need to completely disassemble the governor . Just slide the governor and all thrust washers, thrust bearings in one assembly , remove the spring and shims and slide the spring and governor back on the shaft. There is a small O-ring on the shaft that also needs removed before sliding the governor assembly off. Don't forget to put it back on. I'm not sure what its for but it looks like just an aid for assembly.

The preload on the power valve rod can be adjusted with the small set screw on the back end of the bell crank . I'm no expert on this but we have an ever so slight preload on the small triangle that rotates the power valve to the stop when the PV is completely closed. This may be where the PV slap is coming from if not adjusted properly ??? Thats about all for now. Thanks for reading through all the B.S. Good luck

Would be nice to hear the results from more people as they do this. I'll be following this thread as more do it.

Just as a point of clarification: Do both bikes have the same exact ignitions and flywheels?