If you havent checked your valves..check! By twowheeler (Read 1,514 times)

[mxmatt]

Feb 17, 2014 21:37:35 GMT -6 twowheeler said:

for 150s thats fine

Which? .005 both or .003 intake and .004 exhaust?

[kz1000st]

A 150 should be set at .004 intake, .005 exhaust. When new the exhaust closes up fast, the intake hardly at all. Later the exhaust doesn't close as much but still more than the intake valve.

[clonedrone]

Feb 15, 2014 9:08:29 GMT -6 kz1000st said:

The valves on a China scooter are spun welded where the shaft meets the head. The material stretches for awhile until they get some miles on them. New 50cc engines that only start out at .002 need to be monitored the first couple of thousand miles religiously. After that they stop stretching and can go much further safely.

Sorry Bro going to have to disagree with ya here.
The process is called Inertia Welding. The Finest Valves in the World are manufactured this way, It was invented by CAT tractor, They Inertia Weld Locomotive Cylinders.
The issue is the Valve seats are of a soft Cast iron, Once heat cycled and the engine is broke in the seats pretty much stay in place.

[bailey]

what should they be set for on a tato-50 ?

[twowheeler]

.002-.003 for both. Either works fine. The Gurus prefer the .003 but they will be noisier.

[bailey]

thanks

[mxmatt]

Feb 18, 2014 11:36:15 GMT -6 kz1000st said:

A 150 should be set at .004 intake, .005 exhaust. When new the exhaust closes up fast, the intake hardly at all. Later the exhaust doesn't close as much but still more than the intake valve.

OK, so I just adjusted my valves to .004 intake, .005 exhaust, engine cold, checked before and after tightening lock nut with a slight drag on the feeler gauge.

Results: Motor seems to run tighter with less noise (ticking gone), however I had to adjust the idle up to keep it on and I seem to have lost a step on my acceleration.  Is this normal.  Are there advantages to having them both set at .005 like my manual states?

[kz1000st]

One of the things you have to do is check 'em, rotate the engine a couple of times and check 'em again. I always do that because I've caught a mistake in cam position when adjusted the first time. Once I could have sworn I had it right but when I went around again the exhaust was at .010 instead of .005. You may have it wrong somehow which will explain the loss of acceleration. We all make mistakes and it sounds like that to me.