1984 cr 125 how do u elimanate the atac power valve

vaughan123 · 10-20-2007, 11:53 AM

if any one knows how to do away with the power valve please let me know how.im stuck with this bike right now and the part is discontinued.O if u know some one that has a parts bike that will sell me the power valve assembly that would be great too.PLEASE SOME ONE HELP ME IM DYING HERE

tigmaster · 10-21-2007, 06:30 PM

the power valve is normally actuated by a centrifugal or hydraulic mechanism in the engine. then a linkage goes up through the cylinder into the power valve assembly. if the actual valves are fine then you can cut this linkage and somehow hold the valve assembly in the high compression or low compression state. the other way is to open up the power valve assembly and remove the valve assembly. it is usually on a shaft with a set screw holding it on. these are the basics, if you have more technical questions let me know.

vaughan123 · 10-22-2007, 04:19 PM

Quote:

Originally Posted by tigmaster

the power valve is normally actuated by a centrifugal or hydraulic mechanism in the engine. then a linkage goes up through the cylinder into the power valve assembly. if the actual valves are fine then you can cut this linkage and somehow hold the valve assembly in the high compression or low compression state. the other way is to open up the power valve assembly and remove the valve assembly. it is usually on a shaft with a set screw holding it on. these are the basics, if you have more technical questions let me know.

so how do i do away with it exactly just try to take the guts out and leave the butterfly wide open. im still a little confussed.ive been told the bike wont run with out it.and the atac power valve isnt in the motor it on the beginning of the exhaust

wr250f95 · 10-22-2007, 04:29 PM

Im not sure why you want to take it off

tigmaster · 10-22-2007, 04:52 PM

yes, but isnt it controlled by the motor. the valves purpose is to chnage the compression ratio from low(low rpm's) to high compression(high rpms). it is controlled by the engine, otherwise it would not know the current rpm rating. parts of it go to the motor. no im saying to remove the butterfly valve and whatever else is connected to it. the valve is normally set to low compression so removing it will just default it to always low compression so you will loose power on the top end. what is wrong with it that you need to disable it?

vaughan123 · 10-25-2007, 05:25 PM

the jug below the butterfly valve is broke off and i cant get a replacement becouse its discontinued so im trying to have it run like it should without it.

tigmaster · 10-25-2007, 05:37 PM

what is the jug? idk what you mean. if you can just explain a bit more.

vaughan123 · 10-27-2007, 08:29 AM

There is the section the actual atac casing.Then off the bottom of it is the butterfly valve and under that there is a thing they call the sub chamber that bolts on under the butterfly valve. that sub chamber some how broke off .im guessing that gives it the back pressure to open and close that valve for the power band.the bike runs but its a a slug with out that sub chamber.

tigmaster · 10-27-2007, 10:53 AM

i see this setup is really different than newer models. if you could take a few pictures i would really be able to help.

10-20-2007, 11:53 AM	#1 (permalink)
vaughan123 C Rider Join Date: Oct 2007 Posts: 4 iTrader: (0)	1984 cr 125 how do u elimanate the atac power valve if any one knows how to do away with the power valve please let me know how.im stuck with this bike right now and the part is discontinued.O if u know some one that has a parts bike that will sell me the power valve assembly that would be great too.PLEASE SOME ONE HELP ME IM DYING HERE

10-21-2007, 06:30 PM	#2 (permalink)
tigmaster Administrator Join Date: Aug 2006 Location: Missouri, United States Posts: 7,526 iTrader: (1)	the power valve is normally actuated by a centrifugal or hydraulic mechanism in the engine. then a linkage goes up through the cylinder into the power valve assembly. if the actual valves are fine then you can cut this linkage and somehow hold the valve assembly in the high compression or low compression state. the other way is to open up the power valve assembly and remove the valve assembly. it is usually on a shaft with a set screw holding it on. these are the basics, if you have more technical questions let me know. __________________ --'03 CRF450r-- --FMF Pipe, Pro-Tech Revavle-- --Vortex Basket With Tusk Disks And HP Springs-- --Pro Taper Triple Clamps And Bars-- --Devol Full SP With Moose HGs-- --Renthal 13/50 With R1 Chain-- --Now It Is The End, Probably...-- --'06 CBR F4I-- --Bone Stock-- Check Our Latest How-To Here

10-22-2007, 04:29 PM	#4 (permalink)
wr250f95 Super Moderator Join Date: May 2007 Location: New Mexico Posts: 7,829 iTrader: (1)	Im not sure why you want to take it off __________________ "LIFE'S JOURNEY IS NOT TO ARRIVE AT THE GRAVE SAFELY IN A WELL PRESERVED BODY, BUT RATHER TO SKID IN SIDEWAYS, TOTALLY WORN OUT, SHOUTING'...HOLY S**T... WHAT A RIDE!" this, is why I ride.

10-22-2007, 04:52 PM	#5 (permalink)
tigmaster Administrator Join Date: Aug 2006 Location: Missouri, United States Posts: 7,526 iTrader: (1)	yes, but isnt it controlled by the motor. the valves purpose is to chnage the compression ratio from low(low rpm's) to high compression(high rpms). it is controlled by the engine, otherwise it would not know the current rpm rating. parts of it go to the motor. no im saying to remove the butterfly valve and whatever else is connected to it. the valve is normally set to low compression so removing it will just default it to always low compression so you will loose power on the top end. what is wrong with it that you need to disable it? __________________ --'03 CRF450r-- --FMF Pipe, Pro-Tech Revavle-- --Vortex Basket With Tusk Disks And HP Springs-- --Pro Taper Triple Clamps And Bars-- --Devol Full SP With Moose HGs-- --Renthal 13/50 With R1 Chain-- --Now It Is The End, Probably...-- --'06 CBR F4I-- --Bone Stock-- Check Our Latest How-To Here

10-25-2007, 05:37 PM	#7 (permalink)
tigmaster Administrator Join Date: Aug 2006 Location: Missouri, United States Posts: 7,526 iTrader: (1)	what is the jug? idk what you mean. if you can just explain a bit more. __________________ --'03 CRF450r-- --FMF Pipe, Pro-Tech Revavle-- --Vortex Basket With Tusk Disks And HP Springs-- --Pro Taper Triple Clamps And Bars-- --Devol Full SP With Moose HGs-- --Renthal 13/50 With R1 Chain-- --Now It Is The End, Probably...-- --'06 CBR F4I-- --Bone Stock-- Check Our Latest How-To Here

10-25-2007, 05:25 PM	#6 (permalink)
vaughan123 C Rider Join Date: Oct 2007 Posts: 4 iTrader: (0)	the jug below the butterfly valve is broke off and i cant get a replacement becouse its discontinued so im trying to have it run like it should without it.

10-27-2007, 08:29 AM	#8 (permalink)
vaughan123 C Rider Join Date: Oct 2007 Posts: 4 iTrader: (0)	There is the section the actual atac casing.Then off the bottom of it is the butterfly valve and under that there is a thing they call the sub chamber that bolts on under the butterfly valve. that sub chamber some how broke off .im guessing that gives it the back pressure to open and close that valve for the power band.the bike runs but its a a slug with out that sub chamber.

10-27-2007, 10:53 AM	#9 (permalink)
tigmaster Administrator Join Date: Aug 2006 Location: Missouri, United States Posts: 7,526 iTrader: (1)	i see this setup is really different than newer models. if you could take a few pictures i would really be able to help. __________________ --'03 CRF450r-- --FMF Pipe, Pro-Tech Revavle-- --Vortex Basket With Tusk Disks And HP Springs-- --Pro Taper Triple Clamps And Bars-- --Devol Full SP With Moose HGs-- --Renthal 13/50 With R1 Chain-- --Now It Is The End, Probably...-- --'06 CBR F4I-- --Bone Stock-- Check Our Latest How-To Here

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