Author Topic: Broken Powervalve??  (Read 10464 times)

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Offline bens87braap

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Broken Powervalve??
« on: June 22, 2014, 09:45:28 PM »
Hey guys this is a funny one .

I just got home last night from a weekend away ridding with the boys,  Have some awesome footage from the gopro, more on that later.   We set off on the Sat morning in very cold weather everything was fine until lunch time when something broke in my bike,  I heard a funny sound come from the pipe almost like a rock passing through the pipe,  I stopped straight away and the bike was idling fine,  gave it a few revs sounds different.  I ride up the trail a bit and it wont hit band it just wont rev still has power down low.  We are about an hour from camp site with minimal tools so it was a slow ride back to camp site which is 90 % downhill. 

I hit a mound to hard about half way through on the only big hill we need to climb the bike almost landed upside down hard.  As all the boys were struggling with the hill working out different ways to get up it I fired up my bike and instantly could here the bike was running different i rolled off the clutch and hit the throttle first second third up the hill hitting band all the way spraying mud all over my mates ahhhhh about time. 

I led the rest of the way back to camp site and then didnt want to touch the bike I rode it all day sunday with 2 KTMs a kxf 250 and yz 250 and the old 87 kx 250 was one bike everyone was looking at,  It thrived on the uphill and the suspension ie finally dialled in to me

any idea what the sound was and how I got it to run in band again before I pull it down and do other year power valves fit the 87? I will post a vid of the bike struggling to climb without band almost sounds like a car when u drop a cylinder lol...

Offline dinkyguitar

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Re: Broken Powervalve??
« Reply #1 on: June 23, 2014, 01:23:05 AM »
Glad to hear you have an 87 KX250.

My cousin gave me his and it's all apart get painted and restored.....

I'd pull the pipe off and see if there's that piece inside...

Anyway, us know if you find any power valves. In my quest for parts I haven't see any. Might be good to have a spare.

dinky,

Offline KXDINO

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Re: Broken Powervalve??
« Reply #2 on: June 23, 2014, 06:53:25 AM »
If the part no longer available get it made that's what I do.

Offline bens87braap

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Re: Broken Powervalve??
« Reply #3 on: June 23, 2014, 11:14:57 AM »
tear down is going to happen today I will take some pics of what i find,  Im a bit nervous as I havnt pulled down one of these lol

Offline tobys 2 strokes

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Re: Broken Powervalve??
« Reply #4 on: June 23, 2014, 02:46:46 PM »
87 was a one year only and are quiet hard to find. you could do a slite mod. and run Tecate 4 valves which are normally equellay hard to find but theres a guy on ebay who had some billet ones made. you would need the Tecate 4 rod to run them and have to bore a larger hole on one side to fit the rod.

Offline bens87braap

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Re: Broken Powervalve??
« Reply #5 on: June 23, 2014, 07:26:12 PM »
can someone explain to me why the bike is running great now after dropping her hard.  I just dont get it..   :|

Offline bens87braap

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Re: Broken Powervalve??
« Reply #6 on: June 26, 2014, 10:43:10 AM »
OK I found someone here in OZ that can make the power valves for me he has made power valves for most 80s kx 250 has all the s**t now to pull it all apart and send him the broken bits pics coming

Offline bens87braap

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Re: Broken Powervalve??
« Reply #7 on: June 27, 2014, 07:01:52 PM »
Ok the tear down is done and im missing more than i thought.  My head hurts from thinking but i sorted it out the left power valve was allways broken when i dropped the bike it moved what was left of the power valve and closed off the port hole then when i dropped the bike again it pushed the valve back down to the bottom opening the port allowing me to hit band again.




Offline bens87braap

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Re: Broken Powervalve??
« Reply #8 on: June 27, 2014, 07:02:57 PM »
can anyone tell me what piston I have 556m06800
thanx

Offline queen of spodes

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Re: Broken Powervalve??
« Reply #9 on: June 27, 2014, 11:47:43 PM »

Offline bens87braap

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Re: Broken Powervalve??
« Reply #10 on: June 28, 2014, 01:03:49 PM »
thanx for the info the power valve u found is the one that is good i need left hand side p valve is the one with the bigger gear ill keep an eye out for 125 ones for ya

Offline bens87braap

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Re: Broken Powervalve??
« Reply #11 on: June 28, 2014, 04:14:32 PM »
since the bottom end will be freshened up in 6 months or so I have decided to run without power valves, I will keep an eye out for my items at the same time collecting bottom end seals bearings for the big freshen up. 

Should I still run the ROD-GOVERNOR and just leave out the valves that way the holes are sealed up and just leave out the left and right valves.  Keep in mind I dont race this bike I use it as an excuse to go camping with the boys if the bike aint going well lets just say the bikes gota go and still be reliable.  Any thoughts thanx.  Ben

Offline queen of spodes

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Re: Broken Powervalve??
« Reply #12 on: June 28, 2014, 06:06:39 PM »
The powervalve compartments will fill up with carbon and stuff that will make it harder to repair down the road but if ou can't find the parts you need, that may be the only option.   You'll loose a little on the bottom and maybe a little all over the spread.

Offline bens87braap

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Re: Broken Powervalve??
« Reply #13 on: June 28, 2014, 07:56:46 PM »
im slowly collecting bottom end parts atm  Hopefully i will find the valves in next 6 months before the big rebuild for now i will just run without them Ill let u now how she runs maybe tomorro

Offline bens87braap

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Re: Broken Powervalve??
« Reply #14 on: June 29, 2014, 07:19:13 PM »
Shes ALIVE  runs surprisingly well without the valves I think i might have found a set ill keep awa for the big rebuild

trying to post vid of how she runs

« Last Edit: June 29, 2014, 07:22:48 PM by bens87braap »