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Sunday, September 7, 2008

Royal Enfield maintenance made simple

The single most common maintenance chore unique to the vintage Royal Enfield motorcycle is adjusting the valves. Not for nothing do they make t-shirts joking that "Loud Valves Save Lives." The clatter of valves isn't really loud enough to warn the world you're coming (as loud pipes famously do). There is nothing good about loose valves. Valves that are too loose, or too tight, can be damaged.

Setting them is a chore that is often described. The more it is described, the more daunting it can seem. Let's make it as simple as it can possibly be. First:

1. If the valves clatter more than seems reasonable, they are too loose. If you try to start the motorcycle cold and discover that the kicker just goes down without encountering very hard compression, they may be too tight.

2. Set the piston at Top Dead Center just as you do to start the motorcycle. Watching for the instant the amp meter flicks back to center is a good way to do this (remember, the ignition and kill switch have to be "on" for the amp meter to work).

3. Open the tappet cover and remove the spindle that holds it. That will give you more room to swing wrenches. Try rotating each push rod with your thumb. You should be able to just make them turn. When cold, it is OK for the exhaust valve (it's on the right) to be slightly easier to spin.

4. Once you determine which three wrenches you'll be using, file down their outside edges so they get into the tight space more easily. The filed ends will also mark which end of the wrench to use as you set them down and pick them up repeatedly.

5. Back off the lock nut on the valve you want to adjust. You have to hold the top adjustment nut while you do this (as illustrated above). Now, here is the BIG CLUE NO ONE EVER TELLS YOU: to loosen the valve, turn the bottom adjustment nut counter-clockwise as viewed from above (naturally you have to continue holding the top adjustment nut stationary). To tighten the valve, turn the bottom adjustment nut clockwise. Simple. When satisfied, tighten the lock nut.

6. Start the motorcycle and go for a test ride if you can. More than once I've found that I've made things worse and need to adjust again. This is a matter of error and trial. Don't set the valves the night before and wait to test them until your mates arrive for the big ride the next morning!

NOTE: If you have one of the new Royal Enfields with Unit Constructed Engines you never need to worry about this task. Your valves adjust themselves automatically.

20 comments:

  1. thank u for this valuable information

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  2. Isn't there any spec using a set of feeler gauges? Or always just trial and error?

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  3. good info...but are these loose valves responcible for the tapping sound from the engine?

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  4. No feeler gauges to help you here, but you don't need them. Properly adjusted valves tap LESS than improperly adjusted valves, but you will never eliminate the clatter entirely in a push rod motor like the Bullet. Also, metals expand at different rates so a motor that doesn't clatter when cold may clatter as it heats up or the opposite may occur. And then the clatter may settle down as the motor heats further. As long as it is within the range that no damage occurs, you are fine.

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  5. Hi im pretty new to the enfield world... im trying to adjust my valves however my valves don't look like the illustration. I don't have the hex style shafts or the nuts at all. Its all cyclindical. I have a 2003 bullet es. Im guessing its different? How do I adjust these?

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    Replies
    1. Sounds like the push rods installed upside down.

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  6. Great info, thank you. I too am new to the Enfield family. I just became the proud owner of a 2012 (really a 2011 but new!) Military C5 Bullet. (Army green).
    Good God, I love this machine. Tan single seat with tan saddle bags.
    Ride it after work every day so far.

    Look forward to reading this blog.

    -Tom in North Carolina

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    Replies
    1. Hey Tom, This is Dan. I worked with you and Becky at GNR. I have a 2005 Bullet 500. Text me at 336-457-1953 if you see this mess.

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  7. Sounds easy,but i spend 7 hours with adjusting the pushrods,single cylinder bikes are very tricky.if the engine is cold there are no clatter noises,after 15 minutes the exhaust valve starts to clatter.what is the right thing to do? make the adjustment when the engine is hot,or cold, to loose or to tight. btw there is no up and down play and the Pushrods spin freely.any tips? thanx and ride safe...

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  8. The theory I have heard is that you should adjust the valves as close to the temperature at which they operate as possible. Hot! I make the adjustment when the valves are as hot as I can stand them but of course they cool by the time I finish. If it is any consolation, my observation is that the more miles you rack up the less often the valves need adjusting. I can't explain it, but it seems so.

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  9. I was told that if the rod just spins but there is no up or down motion then the adjustment is spot on. Do mine when cold and they seem to be fine

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  10. I have a 2012 bullet c5 chrome. How do I find tdc WITHOUT an amp meter since mine doesn't have one

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    1. Your unit constructed engine (UCE) has automatically adjusting valves so there is no need for you to ever adjust them. However, should you want to find TDC without an amp meter, simply gently use the kickstarter until you encounter resistance. That's compression: your piston is nearly at the top. Do you have a compression release? You can get closer to TDC by bleeding off a little of the compression, allowing you to move the kickstarter a bit further. You're now at or very near TDC. On a slow turning long stroke motor like this one the piston "lingers" at the top before starting down again. So "close enough" is usually close enough.

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  11. mine is a 2015 Bullet bought in the Philippines..my Km is now Plus 8thou, my concern is some ticking sound when accelerating and flacking sound when decelerating...it seems that the Valves needs adjustment but as stated it is ajusted automatically.. The note said.....NOTE: If you have one of the new Royal Enfields with Unit Constructed Engines you never need to worry about this task. Your valves adjust themselves automatically. How is that?

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    Replies
    1. Thare are a couple of adjustments that can be made but neither are vital as the sounds are not damaging ones. Here's a video to reduce the ticking. It's caused by the cam gear meshes from the crank to exhaust cam gear and then from the exhaust cam gear to the inlet cam gear. It's nothing to worry about but you can make it quieter:https://www.youtube.com/watch?v=LF2hCvyMQ7Y
      The other flacking sound is most likely the primary chain tension. There is a slipper under the primary chain inside the left crankcase cover that the primary chain slips over to keep it in proper tension. Again, it's not actually a problem but you can tune-out some of the sound if you wish.

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  12. The valves in your motor adjust themselves hydraulically as the motor runs (and warms). The same system is used in modern automobiles. Clicking sounds on your machine are usually the automatic decompressor doing its job. Not a worry.

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  13. I have a 2012 that has what sounds like an exhaust leak. I was told that it is the automatic compression release and since it began at 800 miles it has had an affect on the idle and sometimes quits. Any advice? Is the compression release adjustable? Thanks, Chuck

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    Replies
    1. Chuck, I suggest you post this problem on one of the helpful Royal Enfield Forums for analysis by the experts.

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  14. I have just bought a Royal Enfield 535 GT Continental, could some one tell me the service intervals in miles.

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    Replies
    1. https://royalenfield.com/pdfs/motorcycles/brochures/CONTINENTAL-GT-OWNERS-MANUAL.pdf

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