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Adjusting Valves ?
- Thread starter 01ps
- Start date
Even when properly adjusted, there can be a bit of noise, but if you've not set the valves before, you should- then you'll know everything is OK.
You can do this job with a 17mm wrench, a 10mm wrench, a screwdriver and feeler gauges.
Here's what I do. Put it on the center stand (if you have one). Remove the tank and take the plugs out (easier to rotate the engine). Take the alternator cover off. If you are on the side stand, oil will poor out- normal. If you are on the center stand, some oil may drip out- also normal.
Remove the valve cover caps. Rotate the engine (there is an arrow on the alternator for direction) until the mark lines up for "LT"- left top dead center. To make sure you are on the power stroke, look at the intake valve. When it goes down and then back up- the very next time the "LT" marl aligns it is on top dead center on the power stroke.
There should be some play in both rockers at TDC. Get proper sized feeler gauges that can you can bend at the tip- a 45 degree bend is good. You'l see what bend you need. Loosen the lock nut with a 10mm wrench, and then get the feeler for the middle of the range listed in the shop manual (look below). Adjust to a slip fit- some drag, but not a lot. The tighten the lock nut down and make sure it did not tighten up. Then I add an extra step- I go one feeler thinner and there should be no resistance. I go one feeler larger and it should not fit. I rotate the engine around and back to TDC and re-check. Repeat for the exhaust, and then the right cylinder. Button everything up and that should be about it.
Here's what the manual says- with specs:
You can do this job with a 17mm wrench, a 10mm wrench, a screwdriver and feeler gauges.
Here's what I do. Put it on the center stand (if you have one). Remove the tank and take the plugs out (easier to rotate the engine). Take the alternator cover off. If you are on the side stand, oil will poor out- normal. If you are on the center stand, some oil may drip out- also normal.
Remove the valve cover caps. Rotate the engine (there is an arrow on the alternator for direction) until the mark lines up for "LT"- left top dead center. To make sure you are on the power stroke, look at the intake valve. When it goes down and then back up- the very next time the "LT" marl aligns it is on top dead center on the power stroke.
There should be some play in both rockers at TDC. Get proper sized feeler gauges that can you can bend at the tip- a 45 degree bend is good. You'l see what bend you need. Loosen the lock nut with a 10mm wrench, and then get the feeler for the middle of the range listed in the shop manual (look below). Adjust to a slip fit- some drag, but not a lot. The tighten the lock nut down and make sure it did not tighten up. Then I add an extra step- I go one feeler thinner and there should be no resistance. I go one feeler larger and it should not fit. I rotate the engine around and back to TDC and re-check. Repeat for the exhaust, and then the right cylinder. Button everything up and that should be about it.
Here's what the manual says- with specs:
OliverB
XS400 Junkie
Great tutorial!
lhaolpa
XS400 Junkie
Avoid the temptation to adjust to the small side of the range,as the gap is there for a reason,which is to aid cooling,lubrication,and to give the valves time to close completely,let go of heat[or they'll burn]. lha
Right. The exhaust valve especially needs adequate time on the valve seat to transfer heat. If adjusted to tight, the valve is on the seat for a shorter time than intended. If anything, err on the loose end of the specs.
lhaolpa
XS400 Junkie
That's exactly right!When I started driving,everything,[at least that I could afford] had solid lifters that had to be adjusted.After a few learning experiences,I learned to adjust the tappets correctly.Loose and noisy is better than tight and quite. lha
Hishman
XS400 Addict
Most high rpm race engines have very high valve lash and are super noisy. The large clearance aids in high rpm running
