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Old 06-24-2013, 01:32 AM
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Default 94 CR250-Powervalve question

     

Hi, I have a 94 CR250; I was looking at the powervalve today and noticed something odd. The groove in the left sub- exhaust valve is pointing towards the H instead of the L when the motor is off and cold. Does it need to be warmed up, or idling to show an accurate reading? I would warm it up but it's way to late. Any advice is greatly appreciated, I will run it tomorrow and see if it changes.
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Old 06-24-2013, 08:11 AM
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It's possible the PV is stuck in the open position. Take the inspection cvr
off and try to rotate the drum valve to the line up with the "LO" mark.
If it turns with some difficulty, probably due to carbon build up.

dogger
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Old 06-24-2013, 08:10 PM
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Thanks for the reply. I have the right side powervalve case off and i'm looking at the linkage. When I move the valve link assembly left to match the 'L' mark on the other side; i'm fighting the force of the spring. Also, there seems to be quite a bit of free play in the assembly. When i'm off the spring tension, the groove on the left sub exhaust valve is in the middle of the 'H' and 'L' mark.

I have a feeling the 'Lack' or 'pinion shaft' isn't connected properly; there just seems to be wayy to much free play.

The bike starts first kick, idle's perfectly and rev's out without any bog. This may sound stupid but can I just leave it? I'm only 19 and this is my first bike; I really don't want to open the case and screw something up. I called around local powersports places and most won't even look at it, the only quote I got was 625 not including parts ... I can't afford that, I work at Jimmy Johns

Thanks for any help you guys can give me, I truly appreciate it!
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Old 06-25-2013, 12:28 AM
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You don't need to split the cases to work on the powervalve. The governor is accessed through the right crankcase cover and the rest of it is in the cylinder. One of the pitfalls with the 92-01 powervalve set up is the little "crows foot" that connects the governor linkage in the case to the linkage in the cylinder. If this isn't connected correctly, the powervalve can get stuck or flap around on either side of the linkage. Getting to that involves removing the cylinder and checking the connection as described in your manual. Removing the carbon from the PV itself is a matter of disassembing per your manual then using some oven cleaner and elbow grease to clean it and then reassemble per the manual. Sorry to hear the shops in your area won't look at it. Interesting. Sounds like a great learning opportunity for you. As far as leaving it alone, you can certainly do that, but in so doing you are essentially taking your motor, which is considered by many to be the best configuration of Honda's 250 (92-01) and going back to the pre powervalve era of the early 80's. The powervalve, if working correctly will give a much broader spread of power than leaving it alone. Sounds like your PV is stuck open, so you are still getting top end pull but giving up bottom end power. If it were me, I'd spend the $100 or less on gaskets and such and fix it. You might learn something too. Win-win in my book.
JMV
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Old 06-25-2013, 11:09 AM
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on my cr 250 did not know anything about pv . followed manual cleaned all carbon outworks great.
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Old 06-25-2013, 03:16 PM
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Thanks for the detailed responses, I think JMV is right, I'm going to check the 'crows foot' and make adjustments where needed. If I take the cylinder off, do I need to replace the gaskets?
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Old 06-25-2013, 03:48 PM
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Rule 1
Never reuse gaskets.

Thank me later lol
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Old 06-25-2013, 07:24 PM
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U can pull the jug without separating the head from the jug...so u will only need a base gasket...
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Old 06-25-2013, 09:14 PM
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May as well replace the rings while you're in there too, assuming the piston doesn't need replacement. as stated above, get a new base gasket. You're talking about a $10 part that can casue major headaches if it leaks.
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Old 06-26-2013, 11:47 AM
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You don't need to pull the cylinder or covers to clean PV. Clean it first, as suggested above, and your problems could be solved there. It's also free.

---------- Post added at 08:47 AM ---------- Previous post was at 08:33 AM ----------

Here's my PV chamber when I first got the bike. I don't have a pic of the valve but it had about 3/8 in of carbon that covered one side.

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Old 06-26-2013, 12:02 PM
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Sounds like you are rightfully concerned about the crows foot being off. You will of course need the cylinder off for that inspection and correction. your head as noted will not need to be removed, and when possible I suggest that it not be. base gaskets and head gasket reuse (solid metal ones excepted) are items i found it doesn't pay to reuse. in your case, i would look for a thinner base gasket and increase the compression while you are in there too, but that is a personal choice.

all in all that is a very good bike you have. some dual chamber forks on it, and it is about as good as you can get without having something 2006 or newer.
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Old 07-01-2013, 11:03 AM
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Thanks everyone. I haven't had the chance to take the jug off yet(up north till the 7th). I was riding this past weekend at Ceder Creek, Michigan with my friend. I have posted a video of my CR in case anyone is interested in seeing it. Moments before this video was shot; my buddy's 2003 yzf250 motor seized so we were just ripping the CR around. When we got back home he traded the seized yzf250 for a 95 CR250R.

Sorry about the way it looks; I can't figure out how to change it.

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