2001 cr250 cleaning cylinder and ring gap questions

[Mike_socal]

I'm in the process of replacing my first top end. I have a few questions if anyone can help me out.

1. I'm going to wash the cylinder in soapy water with a scotch brite. When I do this do I have to remove the powervalve parts? Will the water get caught up somewhere if I leave the powervalve parts in place?

2. I'm going to spray oven cleaner on the powervalve parts and exhaust valve to get what gunk I can see. The powervalve doesn't seem to be sticking and I really don't want to take it apart. Can I get away with cleaning the powervalve while it's still assembled in the cylinder?

3. The powervalve seems to have a bearing that's exposed when the powervalve cover is removed. After cleaning, do I need to regrease this bearing or just coat the entire powervalve assembly in 2 stroke oil?

4. When I put the rings on the piston, what's the orientation of each ring gap? If the intake was 12 o'clock where would the top gap be and where would the bottom gap be?

Thanks for any help,

Mike

 

[reelrazor]

Umm, the ring end gaps have to be oriented over their locating pins in the piston. This usually means they will be at 1:30 and 10:30 in your example.

I would go ahead and wash the whole deal ONLY if I had compressed air to follow it up(I do).

Just a drop or two of oil on the powervalve bearing. That's all.

 

[Mike_socal]

I do have compressed air. Thanks for the info.

 

[dirt bike dave]

The early '90's to '01 CR250 powervalve is pretty easy to service, and IMO you should disassemble it and clean it if you want to keep it working right for the long term. One good thing, this assembly is noted for not gunking up as bad as some bikes.

Not sure what the service manual says about lubing the bearings (there is one on each side), but I can check my manual when I get home.

 

[crrider999]

i would highly recommend cleaning the power valve i would imagine they are the same as my 02 125 cr and they are a little stiff pulling out sometimes and they are a little tricky to maneuver them back into place but it is well worth it and after you figure it out the first time it is a breeze the next time.

 

[crrider999]

so they are different than my 02 dirt bike dave?

 

[dirt bike dave]

Never looked at a CR125 closely; I know the '02 CR250 got a redesign.