[wally]

I picked up a couple 2004 crf 250's cheap in non running condition. Id like to do a leak down test on them to determine the condiotion of the top end and valves but i cannot find the correct 10mm adapter for my tester. I have the Mac tools motorcycle specific kit and it does have a 10mm adapter but the reach/threads arent long enough. I contacted the Mac dealer and the local honda shop and neither one of them have the longer one. Does any one on here have one or know where i can get one? Or maybe a honda service manual with the part number? Any help is much aprreciated

[crfsonly]

welcome to CRF's Only! congrats on your new ride. once you get it running you'll love it. i'm not familiar with the Mac tools leak down tester so don't know if this Motion Pro will be compatible with it or not:

http://www.crfsonly.com/catalog/product ... ts_id/3701

regardless of the leak down test results i highly recommend you pull the head to inspect/measure the piston and rings for spec. before doing this check the valve clearance. you'll likely find one or more valves tight. if not, and you have a valve spring compressor, pull the two intake valves. if there is a "ring" where the valve makes contact with the valve seat your valves have sunk into the seat and need replacing. this can also happen with the exhaust valves but it occurs faster on the softer titanium intake valves. if they do need to be replaced the valve seats must be professionally cut to restore the correct valve mating angle.

you'll also likely have to do some work on the carb. if it sat with fuel in the carb the jets will be buggered and so will the float and accelerator pump most likely.

if you get in there and have questions let us know.

ken

[wally]

Thanks alot for the tips Ken, I totally forgot about the guys at motion pro! Ive already pulled the valve cover off of one and checked the clearances, thats the first thing I did since I already have an 06 450r that had the valve issues. Sent it down for the stainless valve update 2 years ago and havnt had to adjust the valves since! That thing is now more reliable than my buddies xr lol. but back to the 250, the carb is cleaned out and good to go but Im almost certain the intake valves are toast because it wont even fire once even with a squirt of gas down the hole and it feals REALLY easy to kick over, almost like a 2 stroke.

[crfsonly]

if the valves were very tight then it could explain what you are seeing. if not, then might be rings.

[wally]

Finally found an adapter today, $50 on my local Snap-On truck. Hooked everything up and got 50% leakage on the gauge. Can hear air from the air box so i guess the intake valves are shot.

Now Im not planning on keeping this bike so can I just throw some oem titanium valves in it or do I have to have the seats cut at a machine shop?

[sycraft]

If you are really just going to get rid of it, shim the valves and tell the buyer that they will need a valve job, dont waste good parts on the head without setting it up properly, waste of your money and the buyers.

[124]

...so can I just throw some oem titanium valves in it or do I have to have the seats cut at a machine shop?

Don't do this. You MUST have the seats cut when installing new valves. You will be misrepresenting the "new valves" portion of your sale assuming you list it this way. As mentioned above, save the money and let the buyer know.

[wally]

OK I just wasnt sure if the seats had to be re done with the oem valves or only when switching to stainless. Didnt mean to have it sound like I was going to be misleading to the buyer.

From what Ive read the people who are serious about racing these bike would rather have the titanium valves rather than stainless because of the rpm limitations.

Personaly I ride trails so the stainless ones work fine for me.

[crfsonly]

the Kibblewhite stainless steel valves don't have RPM issues if used with the Kibblewhite high performance springs. if you install the TRX stainless valves there are RPM concerns.

keep in mind, the stock Honda exhaust valves are stainless steel valves (actually a two piece construction of stainless steel). no RPM issues there.

when installing new valves you must have the seats professionally cut to maximize valve durability.