HELP power valve leaking

spinisking

spinisking

New member
Hi all i just got a ec 300 2001 and it was fully rebuilt before i bought it.

it runs like crap i tried everything with carb that's perfect.

tried to do leak down test but its leaking from the power valve bearing.

any help would be greatly appreciated
 
That's normal. If you had sealed bearings, the "air" leak would be a lot less.
Check the reed valve.
 
Last edited:
spinisking said:
they look good to me
Click to expand...
Those reeds are not shutting . This will give poor performance down low . I would upgrade to v force reed assy . You will have to cut the boyseen block off the intake and
Make sure it’s filed flat after or
Buy newer intake . But they should
Not make it run like it is in first video . We had one do that and the power valve linkage pin on lever was broke . Did you run bike with that linkage cover off and see power valve move ? Sounds like power
Valve not opening . Could be stuck . Could be electrical also but I’ve never had electrical issues on any of my Gasgas bikes since 2003 . Check power valve for function .
 
Last edited:
Also might want to pull silencer off
And see if its
Clogged . Run it without and see if runs better . Could be something in expansion pipe also . From laying around off bike . Sounds to be like power valve issues . Could be timing also . Is it a xc or ec . Xc timing could be adjusted don’t recall if they had timing makes . The larger ec had a special washer in one area that set timing correct
 
Hellcat said:
Those reeds are not shutting . This will give poor performance down low . I would upgrade to v force reed assy . You will have to cut the boyseen block off the intake and
Make sure it’s filed flat after or
Buy newer intake . But they shoukd
Not make it run like it is in first video . We had one do that and the power valve linkage pin on lever was broke . Did you run bike with that linkage cover off and see power valve move ? Sounds like powe
Valve not opening . Could be stuck . Could be electrical also but I’ve never had electrical issues on any of my Gasgas bikes since 2003 . Check power valve for function .
Click to expand...
Thanks for the information I'll get some new reeds for now as they are cheap I can not afford v force at the moment but if reeds fix it I'll upgrade in future.

Yes I saw PV moving while revving and I've also had it apart and all moves as it should.
 
Hellcat said:
Also might want to pull silencer off
And see if its
Clogged . Run it without and see if runs better . Could be something in expansion pipe also . From laying around off bike . Sounds to be like power valve issues . Could be timing also . Is it a xc or ec . Xc timing could be adjusted don’t recall if they had timing makes . The larger ec had a special washer in one area that set timing correct
Click to expand...
It's the ec it has the washer I've tested it all and seams right but I'll also try silencer.

Thanks again helps me tick off some stuff
 
You might be able to flip the reeds over . I don’t think the reeds are going to be the issue when it goes to rev up though and cuts out like that . Reeds not closing usually just poor and sloppy low end performance. Your bike sounds like it almost hits a rev limiter . Take a good close up pic of your power valve linkage hooked to the lever on actual power valve .
 
Hellcat said:
You might be able to flip the reeds over . I don’t think the reeds are going to be the issue when it goes to rev up though and cuts out like that . Reeds not closing usually just poor and sloppy low end performance. Your bike sounds like it almost hits a rev limiter . Take a good close up pic of your power valve linkage hooked to the lever on actual power valve .
Click to expand...
the linkage has been welded and looks bent so i have ordered a new one waiting for it to arrive i thought same its like a rev limiter very low rpm lol

yes i bought it like this thinking easy fix as i like the bike. second thing i did was new plug after rebuilding carb.
 
spinisking said:
the linkage has been welded and looks bent so i have ordered a new one waiting for it to arrive i thought same its like a rev limiter very low rpm lol

yes i bought it like this thinking easy fix as i like the bike. second thing i did was new plug after rebuilding carb.
Click to expand...
Get a new Teflon locking nut also . There is a washer that is special also . Prevents binding
 
Like I said friend bought a 2002 years ago and it did and sounded exactly same as yours . His stud on the power valve bracket was broke . Your saying someone welded your stud back onto bracket ?( common , I’ve done it before ) . Your not saying the rod itself has been welded are you ?
 
Another thought . Does power valve fully open ? Wonder if guy installed power valve upside down ? Not sure if you physically can but might be able to . Hope guy who rebuilt engine also installed the oring on the rh crank behind the crank bushing that rides in the crank seal .
 
Think I'll take PV to bits and rebuild it while I'm in there

It all moves freely it didn't open fully when I took cover off and watched it but it would rev fully so thought it wouldn't open all the way
 
On my previous question asking if it was ec or xc . The ec has the large flywheel / stator setup that uses the special shaped washer that sits recessed into stator mount to time correctly . Xc had small setup and no timing washer pretty sure . I changed my old Xc to ec setup 20 years ago . Don’t remember exactly
 
Hellcat said:
On my previous question asking if it was ec or xc . The ec has the large flywheel / stator setup that uses the special shaped washer that sits recessed into stator mount to time correctly . Xc had small setup and no timing washer pretty sure . I changed my old Xc to ec setup 20 years ago . Don’t remember exactly
Click to expand...
Yes it has big flywheel and washer for timing
 
On another note . I’m a Kawasaki Kdx which had similar ignition system the stator tested fine . But aftering changing cdi with new and
Still would not start just backfire . We bought a used stator and bike still runs perfect to this day . Personally I have never in over 20 years had a stator go out on any of my 8 Gasgas bikes . But a 2010 I just rebuilt it runs fine but rectifier / regulator I think is bad . Blew headlight out when I plugged it in . So gotta check that now
 
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