After doing a Valve Adjustment on the Hawk 250 motorcycle I wanted to share the steps in case it helps others who are new to the process.
There are three valuable sources of information for someone who has never done this before.
- There is a valve adjustment discussion on the ChinaRiders discussion board.
- There is another similar motorcycle to the Hawk made by CSC and they have a highly detailed guide to valve adjustments. Although it doesn’t quite match up with the Hawk, it’s like 90% the same. So that helped a lot.
- Motocheez did a video about the Hawk valve adjustments which was very helpful. Here goes:
Having watched and read those I generally followed the CSC guide and referred to Motocheez’s vid as a cross reference. The following are several things to keep in mind. And by the way, it’s much scarier and seems like it’s going to be much harder than it is. So don’t be afraid to try this…
First up, I put the Hawk up on a Harbor Freight ATV / Motorcycle lift.
This specialized jack allows you to securely raise the bike up, using the frame, to a level height that makes things a lot easier. Also, you need the bike to be level as opposed to leaning on its kickstand, because when it comes time to access the crankshaft you’ll drain oil onto the floor if the bike isn’t level.
When you unbolt the valve cover on the top of the engine it will actually clear the frame just fine and there is plenty of room to work on this bike without removing the gas tank. So just take it off and stick your hands in there!
MAKE SURE AND WARM UP THE ENGINE BEFORE MESSING WITH THE VALVE ADJUSTMENT! This step is easy to forget, but its important. Just ride once around the block. You don’t want it too hot to touch, but it should be warm.
Motocheez put his bike in gear and turned the rear wheel manually in order to rotate the engine to Top Dead Center. I found it easier to concentrate by using the wrench method…
Using a 14mm socket and extension, turn the crankshaft COUNTER-CLOCKWISE until it comes to a marking that has a T with a line beside it. You want that line right in the center of the opening, which will indicated that you’ve reached Top Dead Center. This is the point at which both valves are closed and there is the least pressure on all of the components.
When they are at TDC they should look kind of like this. With neither one being higher than the other.
When you go to loosen the adjustment nuts with a 10mm wrench only loosen them a turn or two. You’re going to grab the threaded screw just above the nut you loosened and turn it to manually create a bit of a gap. You’re going to need to use a Feeler Gauge, so if you don’t have one – get it. This one on Amazon has the right sizes for $7.50 Prime.
Basically, you’re just going to loosen the valve adjustment a tiny bit so you can slip in the feeler and make sure its the right gap. It should be .005 on the exhaust side (nearest the pipe that wraps around the engine and goes back to the muffler), and .004 on the intake side (near the tube coming from the air filter).
That’s really about all of the tips you should need. Just be patient, follow the video and the written guide and incorporate these tips and you’ll be fine. It sounds much worse than it is. ;-)