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post #1 of (permalink) Old 03-04-2002, 06:34 PM Thread Starter
 
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Broken Powervalve

Err, I was rebuilding my engine again and noticed that my lack of performance was due to the broken attatchment on the powervalve. I don't know why in the world this happened but here's the deal. Since the engine has been bored out about .02, the powervalve had a little taken off of it. I can get the valve but is there anyway I can shave down the valve without boring the engine again?

If it ain't broke, your not trying hard enough.
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post #2 of (permalink) Old 03-05-2002, 08:31 AM
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Re: Broken Powervalve

you will have to take it to a shop with the cylinder. i think the only way to shape it is boring it again?

post #3 of (permalink) Old 03-05-2002, 11:32 AM
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Re: Broken Powervalve

When I punched my YZ 30 over, I did it with the valve out, put it back in and all was well. Ran it for five years like that.

RoosteR
I love the smell of two-stroke in the morning.....
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post #4 of (permalink) Old 03-05-2002, 11:27 PM Thread Starter
 
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Re: Broken Powervalve

So your saying it's not worth it for the time being until it's time for another rebuild. How much hp will I lose with out it? It only moves at higher rpm's right?

If it ain't broke, your not trying hard enough.
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post #5 of (permalink) Old 03-06-2002, 08:25 AM
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Re: Broken Powervalve

no he was not riding with it out. he took it out while the cylinder got bored. you cannot ride with it out. well you could but the bike would run like complete shiz. you would loose ALL you low end power and have a crazy powerband hit if it hit at all. the exhaust port would be way too big with it out. replace it. its there for a reason. it close the port at low r's and open it up at higher r's for more flow. if you took it out you would loose the very important backpressure a 2-stoke need to run correctly

post #6 of (permalink) Old 03-06-2002, 08:28 AM
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Re: Broken Powervalve

you might be able to grind the vlave your self. just slowy take some of the metal off on the side that is closist to the piston. due it until the piston moves freely in the cylinder. i wouldn't due it this way but hey.

post #7 of (permalink) Old 03-06-2002, 11:39 AM Thread Starter
 
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Re: Broken Powervalve

Crap.. I'll see if it can shaved without having to go a bigger size of bore. I realy don't want to spend the money for a new valve AND piston.

If it ain't broke, your not trying hard enough.
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post #8 of (permalink) Old 03-06-2002, 11:59 AM
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Re: Broken Powervalve

How much did you bore this thing out? The poower valve shouldn't be that close to the piston to begin with. At least mine wasn't anywhere close to having the piston hit it.

RoosteR
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post #9 of (permalink) Old 03-06-2002, 10:13 PM Thread Starter
 
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Re: Broken Powervalve

.03 over I think, it's a 89 if that makes a diff. Maybe it's time to break out my welding skills and try to quick fix it for the time being since the part realy isn't under much pressure.

If it ain't broke, your not trying hard enough.
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post #10 of (permalink) Old 03-07-2002, 11:05 AM
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Re: Broken Powervalve

Mine was a '90 YZ250, over .03. I must be missing something here, I still don't see how this bore could have affected your power valve.

RoosteR
I love the smell of two-stroke in the morning.....
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