Bent tappet??

[Superchuck]

Just rolled over 2000 mi on the thumper so I'm starting my new round of maintenance... checked and reset the spark plug, electrolyte level still fine (have never added fluid) and had to do some adjustments to the tappets. 

Rearmost (intake) tappet was fine after adjustment, but the front one (exhaust) spun a little funny on its axis... I'm thinking it got bent somehow, if ever so slightly.

Is this very bad, what could have caused it, and how can I avoid doing that in the future?  Also, is this something I should fix, or is it O.K.?

Thanks in advance!

Chuck

[tooseevee]

Just rolled over 2000 mi on the thumper so I'm starting my new round of maintenance... checked and reset the spark plug, electrolyte level still fine (have never added fluid) and had to do some adjustments to the tappets. 

Rearmost (intake) tappet was fine after adjustment, but the front one (exhaust) spun a little funny on its axis... I'm thinking it got bent somehow, if ever so slightly.

Is this very bad, what could have caused it, and how can I avoid doing that in the future?  Also, is this something I should fix, or is it O.K.?

Thanks in advance!

Chuck

               Once they bend (if it's bent), they usually just end up bending more. Next time you do your valves, pull the pushrod & roll it on a piece of glass. That'll show you if it's bent & how much.

[barenekd]

If  it is bent, I'd get rid of it as soon as possible. There's nothing good coming from leaving it in there! It cold wreak some real havoc if it goes far enough. The least of which is keeping proper valve clearance. Those things probably rotate and can tear up your cams if they turn sideways.
Check it very closely. If it's bent, lose it.
Bare

[Ice]

 Possibilities include bent push rod, bent or warped adjuster of center hole or threads of the push rod end of center machining or uneven wear of the cupped surface of the push rod adjuster.

[tooseevee]

               Once they bend (if it's bent), they usually just end up bending more. Next time you do your valves, pull the pushrod & roll it on a piece of glass. That'll show you if it's bent & how much.

            You know, I realized last night after I wrote this that it's not so simple to remove Enfield pushrods, is it?  I had harley in my head when I wrote that (sorry, it's been over 60 years). I can have all four pushrods out in 5 minutes without taking anything apart.

             

[Superchuck]

Thanks guys,

I'll look into this next time I get a chance... If it is bent it'd only ever-so-slightly, but I agree that I don't want it to get any worse and wreck something costly.  Haven't looked into the process for removal yet but it shouldn't be that complicated should it? 

[The Garbone]

I imagine to remove the pushrod you just pull the tank, pull the rocker cover, compress the valve and remove the rod..  At least this is how it would work on an iron barrel....

[barenekd]

are you looking at the pushrod being bent?, Or the tappet? The pushrod goes up from the bottom of the cylinder, under the adjuster cover cover. The tappet is under that piece going down though the lower case to the cam. Don't know how you could determine that the tappet would be bent anyway. You can't see much of it from the adjustment hole. If it's the pushrod, see the previous post on getting it out. Not too hard. If it's the tappet, you're in for some major disassembly.
Bare

[Superchuck]

Good Question... I'm still a novice despite my avatar being deemed a 'grease monkey.'  I think it's the pushrod... it's the thing you adjust when you take off the tappet cover that that decompressor cable is attached to.  The things that spin on their axis 'thumb free' but you tighten til there's no up-and-down movement.

I think the hardest part about being new to motorcycles and novice mechanicking is the vocabulary...  i've learned a lot in the past few months but there's still a long way to go.

Chuck

[olhogrider]

That's why they say Royal Enfield has been making mechanics out of riders for over 100 years.

[barenekd]

Superchuck
It is the pushrod your talking about. You just have to take off the tank and rocker box to get to that. You may even be able to see down the hole to determine whether or not it's bent with out actually taking it out.
The easiest way to remember the difference is tappets, si they are also known as cam followers or lifters. They run directly on the cam, and on the UCEs, are replaced by the hydraulic lifters. They both still use pushrods, so are known as pushrod engines, as opposed to Overhead Cam engines, that have the cams in the head and run the valves directly, or in some cases just have the rocker arms. These are made to dispense with the reciprocating weight of the pushrods and tappets and allow higher engine speeds without valve float. Not a great concern on a Bullet.
This treatise could go on forever...I quit!
As for your original question of about how to bend one, I know of only two ways, overrevving, or a sticky valve. The only way I know of to overrev an Enfield is to grab full throttle as you are sitting still in neutral, or miss a shift at full throttle. As far as sticky vlaves go, that's a little tougher one to call, but it can be caused from overheated oil and coke on the exhaust side. It's hard to check for unless it's still stuck, in which case you wouldn't be riding it. Has your bike ever started missing while it was going down the road, then smoothing out again? Could be an indication.
Anyway good luck on your quest.
Bare

[Superchuck]

No, the bike runs and has always ran great...  it's an '09 but was new from the dealership this past february.  The reason I think it's bent is because when spinning it with my thumb it gets to a slightly tighter spot at one point on its axis.  I didn't notice this when I did the first adjustment around 6 or 700 miles, it only appeared now at 2000 mi. 

I heard on here that tappets too loose is better than tappets too tight, so I made sure to err on the slightly loose side when adjusting my pushrods.

If in fact it is bent, should I replace it immediately?

chuck

[The Garbone]

Replace soonest if bent..  On one of mine I thought it was bent, took it out and checked it and figured out it was just an optical illusion of some sort.. Threads,  color, oil drips..  Better safe than sorry though, if it is a crap rod you want to catch it early before it lets you down out in the sticks...

[Arizoni]

I kinda doubt that the push rod is bent.
As barenekd mentioned it is rather difficult to bend one while it is still installed in the engine.

If the only indication is that it has one place that is tight while rotating the pushrod that can be caused just by the normal wear of one of the ends where it meets the rocker arm or the tappet.

In many overhead valve engines it is fairly common for the place on the rocker arm where the push rod fits to become slightly worn and this wear is not always uniform.
If a slightly grooved pocket develops the rod end tends to take on a similar shape leaving some areas slightly longer than other areas.

When someone rotates the pushrod and one of the slightly longer areas passes by the area where the slightly shorter area had been living the rod becomes difficult to turn.

If it were me doing the work, I would just rotate the pushrod to the "looser" position and button things back up after making sure the tappet clearance was correct.

[Superchuck]

Thanks Arizoni and Garbone,

It doesn't seem horribly bad right now, so I'll ride it for a few hundred more miles and see if it's 'bent' itself and more.  If the problem persists or gets any worse I'll pull them out and possibly replace.  Good to know there could be a common reason for this though.  Someone else also PMed me that their bike does this same thing and they think it's fine.

Cheers,

Chuck