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Himalayan Valve Adjustment Questions!

TN_twowheeladdict

Well travelled
Location
Tennessee
I just rechecked my valves yesterday and it really isn't that difficult.

There is enough slack in the wires and hoses under the tank that once you disconnect the fuel pump from electrical and fuel the rear of the tank can be lifted 6 - 8 inches as you pull it back. Prop a piece of board under there and disconnect the evap hose and the electrical connector. I choose to leave the breather hose on the tank and pull it out of the frame.

Set the tank on some boards so the fuel pump doesn't have pressure on it.

Remove the covers to be able to see TDC and turn the engine. Remove the covers to the valves. Remove the spark plug to make it easier to turn the engine.

Rotate the engine clockwise and watch the motion of the valves. When they are both high and you are able to wiggle both you are near TDC on the compression stroke. Rotate it a few times until you are used the movement of the valves.

Then look in the inspection hole and you are probably within an inch of TDC.

I made one of those tools with the square head screw in a piece of hard wood to adjust and hold the adjustment while tightening.

I also cut down a 10 mm box wrench to use on the intake side because it is tight back there with the fuel injector and fuel line from the tank.

Always check the clearance after you secure the adjustment just to make sure you didn't move it.
 

Jerk

The Boss at On An Adventure
Staff member
I'm revisiting this thread because I'm doing my 4th 300 mile service and I am still unsure on the which TDC I'm dealing with.

I have a feeling that many people are adjusting their valves wrong, due to all the misinformation floating out there.

Here's the source of my confusion: I align the T in the side inspection hole. I check the piston location with a straw, and it appears to be TDC. I can only insert the straw about an inch.

Next, I rotate the crank 360 degrees until the T aligns in the inspection hole again. Now, when I check the piston with the straw, it should go quite a ways in, indicating the piston is in the down position. Nope. The piston appears to be at TDC again. I can insert the straw only about an inch.

So, no matter how many times I rotate the engine and align the T in the inspection hole, the piston is always at the top.

Also, I cannot wiggle the valve rocker arm at either location. I've never really been able to wiggle them during my other valve adjustments. Sometimes either the exhaust or intake will wiggle a tiny bit, but never both.

What's wrong with my logic?
 
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Jerk

The Boss at On An Adventure
Staff member
OK, perhaps I'm getting closer. I rotated to TDC several times, looking for wiggly rocker arms. There are times when the T aligns in the inspection hole and I can move the rockers a tiny bit... I'm talking maybe 1/64". I'm assuming that's the correct TDC.

FWIW, I tried the finger over the spark plug hole method, rotating the tire and feeling air pressing on my thumb, but wasn't anywhere close to TDC, so I abandoned that method.
 

CarstenB

Well travelled
Location
h-town tx
the piston will be at TDC each crank rotation (360deg). The straw only helps you to determine if it is at TDC but not if it is at the correct TDC for valve adjustment. Valve adjustment must be done at compression TDC not at exhaust TDC. At compression TDC you can turn the crank a good bit forward without the rockers moving. At exhaust TDC, the exhaust valve is a bit open so you will see it moving if you rotate the crank. At compression TDC the valves must have some play and you can wiggle the rockers. If not you're either at exhaust TDC or the valves are too tight.
So if you are at TDC going by the flywheel mark or straw and you rotate the crank a bit further and you see the exhaust valve moving, you're at exhaust TDC (wrong TDC for valve adjustment). Rotate the crank 360deg and you should be at compression TDC. If you rotate the crank a bit further the exhaust valve should not be moving. Do it a few times so you get the hang of it. It's easy to rotate past the T mark so make sure you don't miss it flying by.


They call the exhaust TDC overlap TDC and it's an overhead cam engine but should give you the idea.
 

sqeeezy

Well travelled
Location
Southern Spain
OK, perhaps I'm getting closer. I rotated to TDC several times, looking for wiggly rocker arms. There are times when the T aligns in the inspection hole and I can move the rockers a tiny bit... I'm talking maybe 1/64". I'm assuming that's the correct TDC.

FWIW, I tried the finger over the spark plug hole method, rotating the tire and feeling air pressing on my thumb, but wasn't anywhere close to TDC, so I abandoned that method.
Just bear in mind that if you rotate the crank CW as viewed from the LHS of the engine, you are turning the engine backwards, which might affect your understanding of what's going on with the order of valves opening and closing. My personal preference is to stick her in top gear and use the rear wheel to rotate the engine in its normal direction.
 

Bradster49

Well travelled
Location
Lille France
It's a shame that Putts video had the couple of errors otherwise it was a very worthwhile view. It would be nice if he or someone re makes an accurately described vid that would bury the black art image that valve clearance checks seems to have at the moment. Am I right in thinking that most of the confusion arises from differentiating between "False" TDC (when both valves are slightly open) and True TDC (both valves shut) Can someone please confirm if the T only appears in the inspection hole at True TDC ?
 

sqeeezy

Well travelled
Location
Southern Spain
It's a shame that Putts video had the couple of errors otherwise it was a very worthwhile view. It would be nice if he or someone re makes an accurately described vid that would bury the black art image that valve clearance checks seems to have at the moment. Am I right in thinking that most of the confusion arises from differentiating between "False" TDC (when both valves are slightly open) and True TDC (both valves shut) Can someone please confirm if the T only appears in the inspection hole at True TDC ?
T appears at every TDC, that's at the end of compression, when both valves are closed "True" if you like, and at the top of the exhaust stroke "False", when the exhaust valve is open (obviously no tappet play) and the inlet has just opened (scavenging/helps exhaust gases out and fresh petrol/air mix in, valve overlap, obviously no tappet clearance here either). The crank revolves twice in every complete valvetrain cycle. It's a four-stroke engine. Suck, squeeze, BANG, blow. Watch the video above and watch it again till it's clear. I'm actually with Putt on not turning the engine backwards, it seems daft to me to turn it CW. But daft to risk undoing the crank nut also, so I turn the motor with the rear wheel in top gear. No reason for him to throw the dolly out of the pram though. C'est la vie...
 
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Bradster49

Well travelled
Location
Lille France
T appears at every TDC, that's at the end of compression, when both valves are closed "True" if you like, and at the top of the exhaust stroke "False", when the exhaust valve is open (obviously no tappet play) and the inlet has just opened (scavenging/helps exhaust gases out and fresh petrol/air mix in, valve overlap, obviously no tappet clearance here either). The crank revolves twice in every complete valvetrain cycle. It's a four-stroke engine. Suck, squeeze, BANG, blow. Watch the video above and watch it again till it's clear. I'm actually with Putt on not turning the engine backwards, it seems daft to me to turn it CW. But daft to risk undoing the crank nut also, so I turn the motor with the rear wheel in top gear. No reason for him to throw the dolly out of the pram though. C'est la vie...
Thanks for your reply. I have only been riding bikes for more than fifty five years mostly single and twin four strokes. Thanks for putting me right. Am off to watch the video a few more times until I get it. Cheers mate.
 

sqeeezy

Well travelled
Location
Southern Spain
Thanks for your reply. I have only been riding bikes for more than fifty five years mostly single and twin four strokes. Thanks for putting me right. Am off to watch the video a few more times until I get it. Cheers mate.
Cor, a lot of oldies on this forum; I started with a crap BSA Bantam in '69 so I reckon you trump me, if you'll excuse the word. I actually had to watch that vid a few times, and I used the slow-down feature on YouTube to make it really simple, doh. I've got to the age where knowledge has started to fall out of my brain now, wonder why....
 

Bradster49

Well travelled
Location
Lille France
Cor, a lot of oldies on this forum; I started with a crap BSA Bantam in '69 so I reckon you trump me, if you'll excuse the word. I actually had to watch that vid a few times, and I used the slow-down feature on YouTube to make it really simple, doh. I've got to the age where knowledge has started to fall out of my brain now, wonder why....
You and me both mate, first bike I shared with my cousin was an RE Flying Flea when we were about fourteen years old.We rode the hell out of it around the orchard behind the house. I bought the Himalayan on a whim really as it is old school and I think a lot of other us 'Mature' riders have fallen for its charms for the same reason, its given me a new lease of life after years of mostly Triumphs and Harleys. Anyhow back on topic ! Wheres a good vid on servicing and valve checks ? Happy days
 

sqeeezy

Well travelled
Location
Southern Spain
Wheres a good vid on servicing and valve checks ? Happy days
Dunno, i just look on YouTube and stalk the forums, there's good and bad info out there. I've watched these for the valve adjustment;
and
the Indian one shows the pukkah RE valve tool, which I might buy if I go to Goa this winter, cos it probably costs thruppence out there. Apart from that for general servicing like I say have a look on YouTube and you can find good info but a fair amount of ill-informed stuff too. Good luck.
 

CarstenB

Well travelled
Location
h-town tx
the issue at hand is finding the correct TDC and the first video is completely wrong in that respect. The second video doesn't address it.
 

TN_twowheeladdict

Well travelled
Location
Tennessee
Dunno, i just look on YouTube and stalk the forums, there's good and bad info out there. I've watched these for the valve adjustment;
and
the Indian one shows the pukkah RE valve tool, which I might buy if I go to Goa this winter, cos it probably costs thruppence out there. Apart from that for general servicing like I say have a look on YouTube and you can find good info but a fair amount of ill-informed stuff too. Good luck.
Have you seen the tool used while the engine is still in the frame? There isn't a lot of room around the intake valve.
 

Bradster49

Well travelled
Location
Lille France
Have you seen the tool used while the engine is still in the frame? There isn't a lot of room around the intake valve.
good question! My guess is that because valve clearances are a regular maintenance item then the work will be done without removing the motor from the frame.

For info the part number for the RE valve adjustment tool is ST-27527-2 But you can find them on most of the usual sites.
 

TN_twowheeladdict

Well travelled
Location
Tennessee
You can make your own valve tool. A Square drive wood screw fits the valve adjuster. Just screw the screw into a bit of wood to make a handle.
View attachment 647
Yes, that is what I did, as I said above.

"I made one of those tools with the square head screw in a piece of hard wood to adjust and hold the adjustment while tightening.

I also cut down a 10 mm box wrench to use on the intake side because it is tight back there with the fuel injector and fuel line from the tank. "
 

Kiwiscoot

Well travelled
Yes, that is what I did, as I said above.

"I made one of those tools with the square head screw in a piece of hard wood to adjust and hold the adjustment while tightening.

I also cut down a 10 mm box wrench to use on the intake side because it is tight back there with the fuel injector and fuel line from the tank. "
Yes I was thinking of your suggestion when I posted it as people started talking about special valve adjustment tools, etc. without maybe realizing that it is just a common square drive screw.
 
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