Tricks / Techniques to setting valves

[Red_Hen]

Hi Gang,

I did check and re-set valves yesterday on my R65LS.  Right exhaust valves was a tad tight and intake was just a tad loose.  After doing right side, decided left side should be re set as right side was noticeably more quiet.  

After valve adjustments, went for a 75 mile ride - I noticed the valves weren't as quiet as when I left - also know this is part of airhead technology.  

Intakes were set at .004 and exhaust .008.  I'd bought (3) Wurth gauges and the 3rd gauge is .006.  I'm wondering if I'd adjusted exhaust valves at .006 if they'd stay quiet a little longer?

Wondering what you guys do.

Also, next time I do the valves, even thought it's extra work and as some say a "PITA," I'm going to disconnect the battery and turn the engine from the allen hole on the generator - finding OT solo is challenging for me.

Upside is bike runs unbelievable - in a good way - lots of power, no backfiring - just a really nice running machine (at the moment).

[Bob_Roller]

I wouldn't go 'tight' on an exhaust valve adjustment .

You can use two feeler gauges to get you're required gap if you don't have the correct one in the feeler gauge set, a .003 and .005 put together will work just fine .

[tvrla]

If they're noisy they're most likely still a bit loose. It's commonly believed they're too tight when quiet, but not necessarily so.

One of the tricks is to push down on the rocker to eliminate any oil film on the pushrod to lifter connections while feeling the gap.

Another is if the push rod will twirl (while feeler gauge installed) it's not too tight.

Something to consider is the low spot of the cam --- where is it exactly? If you've seen a cam, you'll remember that they're not all aligned with the peaks right in line? So using TDC as the place to adjust them is a guess that it's the lowest spot for them both. It's not real critical that you align the engine to exactly TDC. If you see it in the window it's good enough!

I set my valves at .004 and .008. Intakes don't need the clearance since they don't get as hot as the exhausts opening and closing the 'blast furnace door' all the time. One of the considerations in clearance is the larger it is, the longer the valve is on the seat transferring its heat to the head to dissapate.

Another thing to keep in mind is some people think that noisy valves is a good thing - but it isn't. What you're hearing is the rocker hammering the valve stem, wearing both. The rocker has a nice curve to it and once that's damaged it doesn't work as well.

Finally, the valves were probably quieter at the beginning of your ride because the oil was thicker (being cold) and cushioned the rockers more.

There's something magical about these bikes when they're running right, as you noticed. They uplift the soul.

But when they're not (and it doesn't take much) they feel like crap.   I frankly believe a lot of these bikes get sold or put in storage because of this phenomena. It can be as simple as needing the carbs synched or a mixture adjusment.

[Bengt_Phorqs]

For me, any airhead valve adjustment means disconnect the battery ground wire and use an allen wrench to turn the engine.  I've never had any luck just rotating the rear wheel.  Valves should be adjusted when the engine is cold.  Lots of folks also recommend retorqueing the heads before adjusting valves.  I don't subscribe to that but to each their own.

[Barry]

Wondering what you guys do.  

Couldn't agree more with using the Allen key instead of the rear wheel to rotate the engine even if locating TDC precisely is not that critical.  

I've been running wide gaps set at 6 thou and 10 thou and haven't really noticed any increased noise although I do press quite firmly on the adjuster to take up the oil film. There has to be some significant drag on the feeler to be sure of the setting. Excessive noise is more likely due to rocker arm clearance.

I didn't adopt the wide settings to cool the valves though. It's a popular belief that it helps and in principle it must do but if you do the calculations the extra dwell time in contact with the seat is negligible. I estimated an extra 2 thou made a difference of 6 deg in 498 that's just over 1% additional cooling time.

[montmil]

OK, I'll play the odd man out...

I pull the plugs and drop the trans into 4th or 5th gear.

With the rocker covers off, I watch the intake rocker move the valve to its fully closed position. A little wiggle of the rocker and a peek at the white-painted OT on the flywheel confirms it as good.

I just do not care for twisting the Allen wrench in the rotor screw. Never have used that technique.

[Barry]

I just do not care for twisting the Allen wrench in the rotor screw. Never have used that technique.  

I understand the reasoning here and was concerned about it myself. After several years of rotating the engine with the Allen screw I tried undoing it to see if it had gotten over tight and found it was surprisingly easy. So I'm not really concerned any more. I do always remove the plugs though to lighten the load.

To be honest I'd be more concerned about the shock loadings to the tramsmission caused when inching the engine round with the rear wheel. Each to his own though. I think more folks use the rear wheel than the Allen screw.

[donbmw]

I used the alternator bolt one time. To just check you valves I find it a waste of time since you have to disconnect the battery and remove and reinstalled front cover and reconnect the battery. It is just quicker to place the transmission in a high gear and move the rear wheel. If you have a full fairing on your  bike it is even hard to get at the alternator.

[Red_Hen]

All good words of wisdom.

Always something to learn here.

[tvrla]

I never thought bumping the rear wheel to be hard on the transmission. The thought just never occurred to me. I leave the plugs in and it can take a bit to rotate past the compression stroke, but I don't really force it. Pulling the plugs would definitely handle that aspect, and would be quicker than pulling the front cover.

Then again, I don't like pulling the plugs any more often than I have to.

[Barry]

and would be quicker than pulling the front cover.

This where I commit airhead blasphemy !

My earth lead is still in the stock location on the speedo drive bolt so I rarely remove it when I pull the front cover. I know the balance of risks and I know exactly where it would short out if I'm not careful so I've developed a technique of minimising that risk over dozens of removals. It's my choice and I'm not suggesting anyone else do it but it means I can have the front cover off in 60 Secs. One of the things that doesn't help a smooth removal is excessive stiction on the bottom location pin so I make sure that is a nice sliding fit.

One day I'll fit ones of those battery isolator switches but hey show me a motorcyclist that doesn't like a bit of calculated risk. Without 100% concentration we put our life on the line every ride. I just concentrate on what I'm doing when I pull the front cover.

[tvrla]

You know, it wasn't till a few years ago I found out it could be trouble removing the front cover with power connected. I'd been doing it since my first airhead in 1990. Since then I disconnected the negative lead, but recently took a close look at it, and like you, decided to chance it. I guess there's always a chance the cover could slip and contact the hot side of the diode board, but we evaluate the risks and decide from there.