Tappet settings

As I've read through this and other chat sites, I've not see whether tappet settings are supposed to be in metric or imperial measurements. Searching for the information via Google, one says it should be in inches (eg: .08 inch at the intake). But, in reading the detailed Himalayan engine manual that shows the complete engine disassembly and reassembly instructions, the measurement is metric (eg: .08 mm).

It's pretty clear to me in watching some u-tube videos showing how noisy their Himalayan engines are, that some are likely using the inch measure on their feeler guages. It is incorrect. Hence the noise.

I noticed this discrepancy last week when, following the Tec video for installing the performance cam, that the guy said metric. So did the detailed manual he referenced. The Google reference, or at least the one I read, is wrong.

Something to be mindful of.
 

RotorWrench

Well travelled
Location
USA
Another more likely reason many are having excessively noisy tappets after adjustment, even using the correct gap numbers , and based on several YouTube videos I've seen, is the technique used with feeler gauges is incorrect.

For a specific gap between two surfaces to be properly and accurately measured with feeler or wire gauges, the feeler gauge must be in the same plane (lined up and parallel to) as the surfaces you are measuring gap between. Feeler gauge use 101.

In several videos I've seen people bow their feelers to get them in the gap then hold them at an angle while checking gap, which causes false friction (drag) usually resulting in excess gap settings.

Two ways to deal with insuring proper feeler and gap alignment when access is tight is to use angled or bent tip feelers or use the technique that bends/flexes the feeler with your fingertips to ensure the feeler is flat and parallel to the gap while the feeler is inserted and you're sliding it in and out.

Below is a photo of my bent tip feeler gauge ( I bent them myself) when I was doing my Himmi adjustments. Notice the tip is parallel and in alignment with the valve stem and adjustment screw tip surfaces to get an accurate measurement and the drag I'm feeling is gap drag not angle drag. No access or clearance issues either.

That being said, I'd rather have excess clearance than too little. As they say, chatty tappets are happy tappets 😉

20220806_164335.jpg
 
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RotorWrench

Well travelled
Location
USA
+1 bent tip feeler.
(y)


Not 2mm excess clearance, surely? That would be 'SHOUTING IN AGONY' , not ' Happy chatty '.

( "one says it should be in inches (eg: .08 inch at the intake " ). o_O

LOL No, that would be a little much. That phrase actually more aptly applies to older engines with much looser tolerances than ours but I just like using it. 😁
 
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tom_d

Well travelled
Location
US
Agreed about the bending the feeler gauge to make it easy to use, some come that way so you don't have to hassle to much with the set's holder.
Just for completeness, here are the Himalayan tappet clearances as I understand them which each allow for a .02mm range for the min. and max settings.
Intake .08mm - .10mm
Exhaust .23mm - .25mm

I've seen intake abbreviated as in. as well as having in listed instead of mm, it makes me I wonder if the intake being abbreviated tripped some up as well along with the metric/sae/other standards issues.

I've also seen a posting of someone setting their clearances for intake and exhaust tappets to 3 thousandth/inch and 9 thousands/inch respectively. The video in the posting went on to how they could also check by "ear" by wiggling the rockers and listening to the relative differences in sound. I thought it was a joke at first, but someone might think it was a good idea if they run across it.
When converted, the settings of 3 and 9 thousandths of an inch are little below the recommended minimum clearances.
3 thou0.0762 mm
9 thou0.2286 mm
3.5 and 9.5 thousandth/inch would put them nicely in the middle of the ranges. Not a huge concern, but maybe not a best practice for the hotter climates, especially if your gauge or technique is a bit off or if checking by ear.
 

Overdrive

Well travelled
Location
Southern UK
I always set mine to a ‘tight’ 0.010 / 0.25 mm cold, which is the top end of what RE recommend. Not noisy imho, even when really hot. (TEC cam)
Reading through various posts on this and other forums about checking valve clearances, finding TDC on the right stroke, no clearance at all when initially checking them, really rattley now I’ve done them, which one is the intake valve (!) etc etc makes me inwardly cringe as it’s about as simple as it gets to check them correctly.
RE don’t exactly help by instructing people to turn the engine clockwise, which is actually backwards🙄.
No offence meant to anyone, at least people are having a go and hopefully learning.
 

RotorWrench

Well travelled
Location
USA
I always set mine to a ‘tight’ 0.010 / 0.25 mm cold, which is the top end of what RE recommend. Not noisy imho, even when really hot. (TEC cam)
Reading through various posts on this and other forums about checking valve clearances, finding TDC on the right stroke, no clearance at all when initially checking them, really rattley now I’ve done them, which one is the intake valve (!) etc etc makes me inwardly cringe as it’s about as simple as it gets to check them correctly.
RE don’t exactly help by instructing people to turn the engine clockwise, which is actually backwards🙄.
No offence meant to anyone, at least people are having a go and hopefully learning.

Clockwise being backwards true, but apparently there have been instances of the crank nut loosening on people, hence recommendation of clockwise. I actually don't even use the nut, preferring to turn the rear tire. But it does make it simpler for some people. And agreed, it is a simple procedure but well meaning advice and videos have confused a lot of people and display some incorrect or erroneous practices, resulting in incorrect tappet clearances.
 

Eatmore Mudd

Moderator
Staff member
Unless a body grew up with adjustable valves there's a real tendency to tighten em up until the feelers glide nicely. There's supposed to be drag. That's scary to folks who never felt what proper drag is supposed to feel like. Done right they're quiet. Meh, a little loose is better than too tight.
 

RotorWrench

Well travelled
Location
USA
Unless a body grew up with adjustable valves there's a real tendency to tighten em up until the feelers glide nicely. There's supposed to be drag. That's scary to folks who never felt what proper drag is supposed to feel like. Done right they're quiet. Meh, a little loose is better than too tight.
True. One of my powerplant instructors in school, who was also a master machinist, said a good starting point to developing correct feel for feelers is to put a piece of notebook or copy paper between two magazines, grasp the edge of the paper with two fingers and slowly pull it out. That is roughly the drag or feel you are looking for when setting gaps with feeler and wire gauges.

If you want to get really good and develop an accurate feel, get your feeler gauges and a micrometer, set the micrometer to a reading, say 0.25mm, get a 0.24 feeler and run it through the micrometer, getting a feel for the drag or lack of, then put your 0.25 in and feel around with it, drawing it out and back in, being sure to stay parallel and aligned with the gap. It's what we did in school and it works quite well for developing your technique.
 

johnny42

Well travelled
Location
NY State
Every motorcycle engine should have hydraulic valves. Right? I'd pay extra for that feature. Folks that need to remove heads, cams, shims etc (and do the work themselves) can't be happy.

My 2020 Goldwing has 2 kinds of adjusters. Locknut and shim under bucket. I do all my own work. I've never had a bike with shim under bucket (till now) and that inspect/adjust maintenance item is coming up.
 

RotorWrench

Well travelled
Location
USA
Every motorcycle engine should have hydraulic valves. Right? I'd pay extra for that feature. Folks that need to remove heads, cams, shims etc (and do the work themselves) can't be happy.

My 2020 Goldwing has 2 kinds of adjusters. Locknut and shim under bucket. I do all my own work. I've never had a bike with shim under bucket (till now) and that inspect/adjust maintenance item is coming up.
My KLR had the shim and bucket type. It actually wasn't bad to adjust but I made sure I always had a good selection of shims on hand.
 

Bluestrom13

Well travelled
Location
Elswhere
My wife's car has bucket followers - No shims.
The buckets are supplied with ends that come in various thicknesses.
Check interval - not stated in the service schedule. Actual mileage attainable? I don't know, but I know of same model
doing 100,000 plus miles without requiring attention.
It has 3 cylinders (each 333cc), 2 valves per cylinder, and red-lines at 6500 rpm, to produce 70 bhp.

My Kawasaki Z650, back in the 80's never required adjusting in the 8 years and 30,000 miles I owned it.
Similar story with 750 that I had for 20 years.
Wear faces self compensating? Or don't wear? :unsure:
 
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RotorWrench

Well travelled
Location
USA
I bought my KLR with 2500 miles on it, got it home, checked my valves, had to shim both. I checked them every 3 to 4 thousand for the next 69,000 and had to make roughly around 4 or 5 adjustments.

My Dakar required exactly 5 adjustments in 179,000 miles. Both bikes used shims.
 

Roy Gavin

Well travelled
My Honda VFR didn't need any adjustment in 120,000 km, just as well; as adjustment was a 6 1/2 hr job if you followed the book.
All CHECKING was done by factory trained mechanics using the factory issued tool, which was a stethoscope.
Honda had to get it right to save face, the first VF bikes were extremely sensitive to clearance and would wipe the cams if the clearance was out.
And sometimes if it wasn't!
Honda finally issued a tool to enable accurate setting on the early bikes, it was reputed to take the thickness of the oil film into consideration.
My BMW R80 G/S PD hasn't needed adjustment in 220,000 km, Mobil M1 and keeping the revs under 5000 probably helps.
Hima went from 5000km to 45,000 before the inlet tightened up a little, with same treatment.
 

RattlingJock

Getting there...
Location
Scotland
I always set mine to a ‘tight’ 0.010 / 0.25 mm cold, which is the top end of what RE recommend. Not noisy imho, even when really hot. (TEC cam)
Reading through various posts on this and other forums about checking valve clearances, finding TDC on the right stroke, no clearance at all when initially checking them, really rattley now I’ve done them, which one is the intake valve (!) etc etc makes me inwardly cringe as it’s about as simple as it gets to check them correctly.
RE don’t exactly help by instructing people to turn the engine clockwise, which is actually backwards🙄.
No offence meant to anyone, at least people are having a go and hopefully learning.
The engine runs counter clockwise? Thanks, newbie here and did not know that!
 

Overdrive

Well travelled
Location
Southern UK
L
The engine runs counter clockwise? Thanks, newbie here and did not know that!
ooking at the bike from the left hand side (the gear change lever side) the engine runs in an anti clockwise direction, the same as probably 99% of all bikes ever made.
For some reason (possibly the remote risk of undoing the flywheel nut) RE instructions tell you to rotate the engine clockwise when finding TDC, which results in the cam chain pulling against the tensioner, which is not good, plus It’s also managed to confuse numerous people regarding valves opening and closing….as everything happens in the wrong order…….
 

RotorWrench

Well travelled
Location
USA
L

ooking at the bike from the left hand side (the gear change lever side) the engine runs in an anti clockwise direction, the same as probably 99% of all bikes ever made.
For some reason (possibly the remote risk of undoing the flywheel nut) RE instructions tell you to rotate the engine clockwise when finding TDC, which results in the cam chain pulling against the tensioner, which is not good, plus It’s also managed to confuse numerous people regarding valves opening and closing….as everything happens in the wrong order…….
That's all true but compression stroke is compression stroke regardless of direction of rotation and is easily identified by holding your finger over the sparkplug hole while turning the engine.

But, for one of the reasons you mentioned, I prefer to turn the engine normal rotation by having the bike in 5th gear and turning the tire.
 
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