Power Valve Adjustability

[gassi]

We have changed the CDI around with no difference. We are going to pull the clutch sides off to take a look at the difference in shims ,spring etc. There is a difference some where and we have covered everything with confidence other than this subject. The 06 pulls like a mild 500 and the 08 is a good 250 but i know of 250's that are stronger.

The Trusty's power valve adjuster would be a real nice add on but if it wouldn't give the same power delivery as the 06 I'm not spending the cash to find out. Just by the seat off my pants I would think it would limit the opening of the PV more than boost it. JMHO.

Ross, the adjuster screw 3 is for what I suspected in the linkage position . Thanks for clarifying. The shims and spring is what I would be looking at to adjust on rate and timing of the PV.

I would really like to know what is change in EC 300 motor after 2006...
Let's try keep this thread alive, because I think there is many who is wondering with the same question?

I have 08 EC300 and I am very disappointed motors bottom end and mid range torque compare to 06 EC300.

-Look like it's not matter of CDI
-I am playing with the powervalve spring preload too, no big difference.
-Maybe spring is different?
-Is there made some changes to crankshaft? (As many you know the partnumber didn't always tell the thruth when we talk about gas gas...)

Maybe somebody who have good contact directly to the factory can try to find out what they do the 300 motor after 2006? Berkyboy...???

I'm very pleased to hear good advices!!!


Thats what I found from http://www.tmxnews.co.uk/content_database/gas_gas_2007_range/index (It's data of the 07 GG bikes)

"The 250 and 300 models get a new crankshaft counter balancer, a re-designed exhaust valve and a new Vertex piston. The changes made to the 125 are designed to simply improve performance, while the modifications to the 250 and 300 are to further smoothen the power, so Gas Gas claims."

I check it and exhaust valve and crankshaft counter balancer really have a different part numbers after 2006. Maybe there is the secret...?

 

[cladoo]

My '07 seems to have more bottom and midrange than my '06 ever had. It runs way better and cleaner. That said, I have another '07 in the garage right now and it seems to have softer power than mine???

 

[101racing]

Gassi,
We have had allot of experience with this subject. I had a EC300 08 and my son has a DE300 06. The 06 always had more off idle massive torque that is very linear. We measured port timing between the 2 bikes along with CDI box's swapped ,ignition timing check,swapped carbs. These are the 3 main problems or differences that we found. The 08 "rain sunshine" mapping switch was faulty on the 08 and was always in the rain mode. The 06 had no shims under the powervalve governor spring and we duplicated that on to the 08. We took all of the base gaskets out of the 08 but one .3mm . It lowered port timing and boosted compression. The 08 had a 14 oz FWW also and the motor now has incredable torque and power botton to top. I sold the 08 with great apprehension to try out a new Husaberg. Hope to get another GG some day. My son has an almost new 06 200 GG that I might buy from him. It is a fun bike to ride.

 

[gassi]

Did anybody knows what is the difference between 06/older EC300's center exhaust valve (ME25616015) and 08 EC300's exhaust valve? (ME250616015-1) I get this older model valve, but I can't find any difference from it... I guess that gas gas deliver the same valve with a different part number and they don't produce that older model anymore?

I'm still looking that incredible low and mid range torque to my bike, what I had in my 06 EC300. Now I have in my bike (EC300 08) the older model crankshaft counter balancer which have more weight, but I'm still not satisfied for the results.

 

[lankydoug]

An important thing to remember when looking to improve low or high end power is that it's rarely one change and it's better. Adding fuel earlier may not help improve low end power unless you change the spark curve to ignite the fuel earlier as well. Increased compression will almost always improve torque but often requires a different spark advance curve along with a change in jetting. If your combo is near perfect changing any one thing will probably make it worse but may have the potential to improve it in the long run when other factors are matched with the change. Sorry if this seems to go on and on but my point is when you get it right it will also only stay that way until the weather and air density altitude changes. Happy tuning an keep a log book so you can find your way back.

 

[gassi]

Did anybody knows what is the difference between 06/older EC300's center exhaust valve (ME25616015) and 08 EC300's exhaust valve? (ME250616015-1) I get this older model valve, but I can't find any difference from it... I guess that gas gas deliver the same valve with a different part number and they don't produce that older model anymore?

I'm still looking that incredible low and mid range torque to my bike, what I had in my 06 EC300. Now I have in my bike (EC300 08) the older model crankshaft counter balancer which have more weight, but I'm still not satisfied for the results.

Well, I answer my own previous question...
I finally made some progress with this subject:
I talk to former Gas Gas EWC-mechanic and he tell me that the years ago when he was working with Gas Gas they use honda CR 250 exhaust valve in Gas Gas 250 and 300 and it should be same part than the early years Gas Gas valve. They spend some time with the exhaust valves and I think they weld or something like that and modified them by themselves.

As I told my earlier post, when I buy this older Gas Gas exhaust valve, I get exactly same valve that I have in my '08 EC300.
So I decide to purchase honda CR 250 exhaust valve, honda part number: 14201-KZ3-690 and I noticed that it look pretty much same than my bike's exhaust valve, but the valve's underneath shape is visible different and the honda valve would be about 1mm lower than original valve when installed. (I try to attach some photos...)

When I try to install it to my bike, I noticed that the valve didn't move freely.
I had to cut off about 1mm from valve's front end (which is facing to the pipe) and then it move's freely and from the former Gas Gas EWC-factoryrider's recommendation, I took the cylinder head off and check with the piston ring that it won't make contact to exhaust valve when the valve is in closed position. (I took old piston ring and when the piston was in BDC I push the piston ring in the cylinder with the old piston and put it to the position when it was closest to the exhaust valve and make sure there was some clearance)

I've been tested it only couple of rides and we have so much snow here that the conditions to the test ride aren't best possible, but I have to say it feels like I finally get the bike's motor really close what the '06 EC 300 was!!!

Low and mid range are significant stronger and bike feel's to pull way better all the way to power band but I don't feel it hit too hard. Now I can use to many places a bigger gear than earlier and that will make the riding much more easyer.

If you like to try this, you have to do it on your own risk!
Only strange thing what I noticed to chance, was the motor's sound when it run's and especially when I use much torque.
It's hard to describe but it's not mechanical sound.
I look to the piston from the exhaust port and there was no trace's that the exhaust valve are making contact to the piston.

What's your thought's about this whole exhaust valve case, guys...?

I've been interested to see if anybody have picture from the 2006 or older EC 250 or 300's exhaust valve.

Left is the Gas Gas exhaust valve up from to 2007 and right is the CR 250 exhaust valve.

 

[john47]

gassi, Thats great work, I'd try that myself if I had a GG. Maby soon! Keep us informed on how it works. Nice to have access to ECW mechanic. Lots of changes going on with the EWC bikes, that make them work better than production units, and the information is never passed on. Like Meo Husky, uses a Showa shock and different link system. I won't be surprised now that GG has a US distributor, "that has motorcycles and racing in his blood", and can phone the Factory or who-ever, for latest technology and racing changes, and pass that to the dealer,and dealer to rider, can keep a GG in it's newest racing form. It's always nice to have that edge, even psychologically .

 

[Berkyboy]

A couple of comments on this thread:

1) The adjustable TRUSTY Powervalve Cover comes with a modified left powervalve, where the shaft has been lengthened about 1/2 an inch with a slot cut in it, where the spring attaches when the new cover is installed. Retail pricing on that valve alone is over $100 before it is modified and obviously adds to the cost of that whole kit.

2) While at the factory last summer I noticed that they had a large quantity of different color coded powervalve springs in stock, indiciating to me that something was different between them. I would speculate that they are in the process of changing something there but I haven't heard of anything official nor did I see them in use during the assembly process of the 2011 bikes.

3) Checking the power valve actuater arm for excess slack and possible binding is the best thing to do when trouble shooting any power delivery problems of a properly jetted GasGas.

Steve

 

[shedguy]

I am surprised no one has mentioned Tulio Provini's TEC hydraulic power valve adjuster, I spotted this item at the Parry Sound WEC back in 2007, an was very curious, well after 3 1/2 years of using this little gadget I won't ride without one what a simple but effective invention, all the husky CH 2 stroke guys' have been using them for some time now. The install time is less then 30 mins with immediate results. I know this thread is old but I just joined up so excuse my revisit of an old subject, the forum is very humble and informative so a big hello from Shedguy. I recently ordered my first GG and am stoked to feel the electric they possess, I will be sharing my riding time with my Husky but who knows, the WR may get some man cave time. Happy New years to a great forum!!!!

http://www.officineprovini.it/eComShop/eComShop_viewItem.asp?idProduct=6087

 

[hannesd]

I am surprised no one has mentioned Tulio Provini's TEC hydraulic power valve adjuster, I spotted this item at the Parry Sound WEC back in 2007, an was very curious, well after 3 1/2 years of using this little gadget I won't ride without one what a simple but effective invention, all the husky CH 2 stroke guys' have been using them for some time now. The install time is less then 30 mins with immediate results. I know this thread is old but I just joined up so excuse my revisit of an old subject, the forum is very humble and informative so a big hello from Shedguy. I recently ordered my first GG and am stoked to feel the electric they possess, I will be sharing my riding time with my Husky but who knows, the WR may get some man cave time. Happy New years to a great forum!!!!

http://www.officineprovini.it/eComShop/eComShop_viewItem.asp?idProduct=6087

how and where do you install this thing and what does it do exactly?
i don't speak italian so can't understand a word on that link

 

[husley]

and

how and where do you install this thing and what does it do exactly?
i don't speak italian so can't understand a word on that link

and the price ?

 

[husley]

flywheel

The 08 had a 14 oz FWW also and the motor now has incredable torque and power botton to top. QUOTE]

14 oz made it torquey off the bottom ?

 

[shedguy]

Not to sure if any interest would be generated but since you ask, they run about $300, I realize the site is in Italian what happens is they bolt the device to a machined power valve cover, and all you have to do is bolt it on, if you can see on my Husky the actuator moves from front to back with the back position being the low end torque/mud mode then you can slide it on the go to the middle and that would be stock, and the front position is an MX type feel, the beauty is you can change out the cover for a different bike or just move it over to your next GG,