Valve Adjustment Tutorial

[chuck]

Originally Posted by hotform

I am posting this in this thread for future reference. I had posted it earlier in response to someone that was having trouble adjusting their valves.

Are you guys using the metric reading on your gauges of .05 and .08 or are you using the American system of inches at .005 and .008? If you are using the latter, then you are setting them way too loose. My big V twin cruiser is set for .003 and .007 American.
The correct American inches in thousandths settings would be more like .0015 for intake and .0025 for exhaust, which is where I set mine with no tick. Or for those not looking at all the zeros, one and a half thousandths for the intake and two and a half thousandths for the exhaust. Not much in other words.
Are you at the correct top dead center when setting the valves? It is a 4 stroke motor, so the piston is at top dead center twice during the four strokes. At the TDC of one stroke the exhaust valve has just finished its business and the intake valve is ready to start its business and both valves are fully loaded and this it not the place to set your valves. At TDC of the compression stroke both valves are slightly relaxed. After you pull off the inspection cap on top where you line up your timing mark, is there a cover down around the side with 4 bolts in it that you can take off? If so, put a drain pan under it and take it off, you won't loose too much oil. There should be a bolt inside that you can put a socket on to turn the engine over. Take the spark plug out so it will turn easier and so you don't have to worry about undue pressure creating resistance and somehow loosening something up. Turn it counterclockwise to line up the timing mark. This is in the Lifan owners manual.
When you reach the timing mark, grab the rocker arm at the adjustment nut of the exhaust valve and see if you can wiggle it up and down slightly. If you cannot, then you are at the wrong place in the 4 stroke cycle. Go around 360 degrees and do it again. Do they wiggle now? Compare the two times you did it, which one wiggled. It must wiggle or you do not have the valves relaxed. If you have set them incorrectly at the wrong mark, and I suspect you have, then they will wiggle a bunch when you are in the right spot.
If you are working with the American inches system then set them to .0015 intake and .0025 or .002 exhaust. My needed settings were printed on a label under the left side of the seat.
Need a tool for moving the little square adjuster on top? You can make a quick one out of a number two square drive wood screw and a small yellow wire nut. Just cut the screw back a bit and screw it up into the wire nut. Or a strip of old credit card works great with little square cut out of it.
Now if you are in the right spot at TDC, loosen the nut on top of the adjuster with a 10mm wrench. Insert the correct feeler gauge. Screw the adjuster down with the wire nut tool you just made. Check to make sure your feeler gauge will still move, but just barely with a lot of drag. Now while holding onto the wire nut tool so the adjuster doesn't tighten as you tighten down the nut.
The following is a nice tutorial on adjusting valves. It was made for larger V-Twin Suzuki's, but the principles are the same. This is where I learned to do it working on my street bike. When I did my Lifan valves Friday, it only took me a scant 15 minutes to do so, as I was now an expert from doing my Suzuki a while back.

http://www.therusks.com/index.php?mo...JAS_File_id=50

Here are the links to three pictures showing the tool made out of a wire nut.

http://www.motorcycle-journal.com/fo...justment-1.jpg

And this one.

http://www.motorcycle-journal.com/fo...justment-2.jpg

One more

http://www.motorcycle-journal.com/fo...justment-3.jpg

One more thing, be patient. The first time I ever did valves I thought I was going to kill someone or something I got so frustrated. It wasn't until I had a cold beer, sat down and thought about 4 strokes and realized the relaxed position I needed to have the valves in, that I got it right. I think a lot of people get frustrated the first time they do it, and a lot of them end up with valves that tick and have to do over again.

Thanks hotform,mine where adjusted wrong.I followed your thread and the correct gauges 0.04mm and 0.06mm and it sound great now.No more excessive tapping.

[Weldangrind]

Wow, this is an eight year old thread that is still helping people!

[SpudRider]

Originally Posted by Weldangrind

Wow, this is an eight year old thread that is still helping people!

That's why this thread is in the Tech Sticky.

[Merlin]

Its helping me today with my new Bashan Blaze 250. Thanks for all the good info guys!

[Ariel Red Hunter]

Originally Posted by red2003

The specs are directly from my Roketa manual that came with the bike. No max or min, valve lash IS what it is. Running the valve clearance tighter then spec is a bad idea. It is set to factory specs for a reason. If you set it too tight, the valves will be held open when the motor heats up and you will LOSE performance. Setting the clearance tighter might get you a little more valve lift safely, but it would have nothing to do with the duration. Cam lift duration is a function of the cam lobe profile, and that can only be changed with a different camshaft.

Red, setting the valves too tight will cause a lot more problems than poorer performance. Overly tight valves cause 750 degree exhaust gas to escape through both valves. This is not as hot as an acetylene torch, but it is hot enough to cut the valve and valve seat in a comparativly short time. It is imperitive to have the valve clearances set correctly, or slightly loose. Slightly loose causes much less grief than slightly too tight.

[simonjester]

Originally Posted by Merlin

Its helping me with today my new Bashan Blaze 250. Thanks for all the good info guys!

This is the best forum in the world!!!