Valve lash

[edog]

I have a g-16 I believe 301 that states in the manual valve lash .004, however side of engine says .008-.012. Which is it? Also what is the correct g-22 valve lash with 357 engine. It also states .008-.012. Please help

[edog]

I think I answered my own question.

.004 valve lash (inches)
.008-.012 (mm)

All Yamaha 4 strokes

[Mike Mac]

the new motors, are at .008. I believe the G16 is the new style motor. Set both motors at .008!

Ta heck with metric!!

[smallblock450sl]

We.ve had this discussion before. Don't have a "drive" manual in front of me, but all 4 cycle Yamaha's thru G16 call for .004 thousanths when cold. I beleive the .008 is the metric equivelant. I still adjust them to .004, .008 thousanths would be loose. Just my 2 cents worth

[edog]

Thank you that clears it up!!!

[Mike Mac]

Guys, .004 in metric is .102 mm

.008 in metric is .203 mm

I think the G16 motor should be gapped at 8 thousand's (.008 ), or .203mm

[smallblock450sl]

Originally Posted by Mike Mac

Guys, .004 in metric is .102 mm

.008 in metric is .203 mm

I think the G16 motor should be gapped at 8 thousand's (.008 ), or .203mm

I disagree Mike. J38 thru G16 calls for 0.004in or 0.1mm. Hope you don't lose a push rod out in the sticks with a loose adjustment That's all I have to say on the subject.

[Mike Mac]

Go with Block, cause he has the experience. So .004 it is!! Sorry Dave!

I set the G22 I did, at .008. It sounded very good.

[sho305]

0.1mm is about 4 thousandths or .004 (actually .0039 or something). Sometimes I use this daily for tolerances lol. Most small engines like lawn engines you can set to .004. The guys that race clones and briggs usually set them to 0 or very close, as they usually get larger when hot. They want max lift for more power, though .004 lift is likely about worth .01 hp or whatever, but when you are racing you get what you can. I set the clone at .002-.004, but have backed off the comp release valve to larger lash to get them to idle slower without the comp release kicking in as much. I've been in a lot of different engines and usually set them as they say, not really sure it makes much difference if they are off a hair. You need to have some lash so the valve closes all the way, it would be bad to have it less than 0 that could trash the valve and lose compression/etc. Some engines may get less lash when hot but I've not run into one. These are said the alum cylinder expands more than the steel pushrod, and so why they get more lash hot.