ChinaRiders Forums - View Single Post - TT250: First valve clearance check report

schleppy · 03-28-2019, 12:42 PM

First valve clearance check report (502 miles). Overall the job is pretty straightforward. I pulled the tank and everything off the first time to get the most work space available. A few notes for others:

1.) To get the CSC cover off that covers the bolt that lets you turn the crank, make DAMN sure you have the right size large screwdriver. Those screws are so tight from the factory. I ended up having to use a large screwdriver and a wrench. I pushed the screwdriver in as even as possible (force towards the bike), then used a wrench to gently turn the shaft of the screwdriver. That did it cleanly with no damage to the screws. Don't skimp on the right screwdriver.

2.) Getting the valve cover off took some time, as it was stuck on there pretty good. I ended up using a piece of plastic blocking I had on the left side (clutch lever side) of the valve cover, getting it under the "lip" and gently tapping that plastic with a small hammer to get it free. Once it popped off everything looked good, gasket was fine.

3.) The manual doesn't say anything about which way to rotate the bolt on the crank to spin the motor (after you remove the spark plug). You turn the wrench counter-clockwise to spin the motor to the right spot.

4.) Rotate the crank a few times and watch how the rocker arms move, and then rotate it to the T mark a few times to get a feel. Rotate the crank SLOWLY when you see the first mark (the double line). The double line, F, then T are all very close together. Also, my valves were really tight at 502 miles, so there was essentially no rocker arm movement at top dead center, making TDC a little tougher to find.

EDIT: Joey at CSC gave me the best tip for finding TDC. As you rotate the crank, watch the exhaust valve (the one towards the front of the bike) open (you see the rocker arm push down) then close, then watch for the intake valve (the one closest to the carb) to open and close. As soon as you see the intake valve close, SLOWLY rotate the crank until you get to the T mark. That is TDC. Without this tip it's much harder to figure this out.

5.) Get yourself a tool to turn the square adjuster:
https://www.ebay.com/itm/223294839859
Getting the gap dialed into .07mm, holding that steady, AND tightening the lock nut with a 10mm wrench can be a pain. Ideally, I would probably do this again with a friend. One to turn the square adjust and get the gap set, another to tighten the lock nut. It's fiddly if you are by yourself. Tightening the lock nut often snugs up the valve clearance a little too much.

I know that sounds like a lot, but it really was pretty straightforward, and the CSC guide for the job is good. Finding a .07 mm feeler gauge was impossible, so I used a .06 as a "go", and a .08mm as a "no go". I think I got it damn close to .07mm.

After adjusting the clearance on my bike, it starts up SO much faster now. One tap of the starter from cold it and instantly started. If your bike is tough to start, you may want to adjust your valves a bit earlier than 500 miles.

Happy wrenching!

03-28-2019, 12:42 PM	#1
schleppy Join Date: Jan 2019 Posts: 27	TT250: First valve clearance check report First valve clearance check report (502 miles). Overall the job is pretty straightforward. I pulled the tank and everything off the first time to get the most work space available. A few notes for others: 1.) To get the CSC cover off that covers the bolt that lets you turn the crank, make DAMN sure you have the right size large screwdriver. Those screws are so tight from the factory. I ended up having to use a large screwdriver and a wrench. I pushed the screwdriver in as even as possible (force towards the bike), then used a wrench to gently turn the shaft of the screwdriver. That did it cleanly with no damage to the screws. Don't skimp on the right screwdriver. 2.) Getting the valve cover off took some time, as it was stuck on there pretty good. I ended up using a piece of plastic blocking I had on the left side (clutch lever side) of the valve cover, getting it under the "lip" and gently tapping that plastic with a small hammer to get it free. Once it popped off everything looked good, gasket was fine. 3.) The manual doesn't say anything about which way to rotate the bolt on the crank to spin the motor (after you remove the spark plug). You turn the wrench counter-clockwise to spin the motor to the right spot. 4.) Rotate the crank a few times and watch how the rocker arms move, and then rotate it to the T mark a few times to get a feel. Rotate the crank SLOWLY when you see the first mark (the double line). The double line, F, then T are all very close together. Also, my valves were really tight at 502 miles, so there was essentially no rocker arm movement at top dead center, making TDC a little tougher to find. EDIT: Joey at CSC gave me the best tip for finding TDC. As you rotate the crank, watch the exhaust valve (the one towards the front of the bike) open (you see the rocker arm push down) then close, then watch for the intake valve (the one closest to the carb) to open and close. As soon as you see the intake valve close, SLOWLY rotate the crank until you get to the T mark. That is TDC. Without this tip it's much harder to figure this out. 5.) Get yourself a tool to turn the square adjuster: https://www.ebay.com/itm/223294839859 Getting the gap dialed into .07mm, holding that steady, AND tightening the lock nut with a 10mm wrench can be a pain. Ideally, I would probably do this again with a friend. One to turn the square adjust and get the gap set, another to tighten the lock nut. It's fiddly if you are by yourself. Tightening the lock nut often snugs up the valve clearance a little too much. I know that sounds like a lot, but it really was pretty straightforward, and the CSC guide for the job is good. Finding a .07 mm feeler gauge was impossible, so I used a .06 as a "go", and a .08mm as a "no go". I think I got it damn close to .07mm. After adjusting the clearance on my bike, it starts up SO much faster now. One tap of the starter from cold it and instantly started. If your bike is tough to start, you may want to adjust your valves a bit earlier than 500 miles. Happy wrenching! Last edited by schleppy; 03-28-2019 at 05:48 PM.
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