Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Some days I feel like this

Discussion in 'Maintenance and Servicing' started by mattb, Apr 15, 2012.

  1. [​IMG]

    Adjusting the valve clearances on the Bullet is about as simple as any motorcycle could possibly be. As you can see above. It takes 30 seconds to check the clearances of the push rods, and 2-3 minutes to adjust them. Just check that they swivel around with ease and have no clearance up and down.

    I kept not getting TDC when I thought I had (my ammeter doesn't seem to be working right). So my inlet valve seemed really tight but in fact I was not at the right piston position.

    Eventually, after so much turning of bolts and surfing of the web, I decided to give the kicker a spin while looking at the pushrods...and I wasn't on TDC at all as was evident by how easily the rigid rod swiveled just a second later. And now it was all whack from my stuffing around.

    Anyway, easy enough to fix. But I decided I should check TDC the old way so as to do no more hacking: plug out, a chopstick down the hole, and start pumping the kickstarter to find where the highest point it. Crunch! Something lodged against the chopstick and wouldn't let it go. So, I got the bike into 2nd gear and spun the wheel backwards and it came loose. I broke the chop stick down so as to get in further under the tank and tried for a more vertical angle. Crunch! Oh dear.

    I ended up just adjusting the pushrods at the engine setting that might have been TDC but which was where the rods swivelled. This 1950s design engine is so clattery that you cannot hear the valves even if they were loose (At least I assume so - God forbid if you could!).

    Such a simple design. So stuffable by a mechanical moron like me. Some days I just feel like this:

  2. does your Enfield do speeds close to 300kph?
  3. You could always do it the really old fashioned way. Start 'er up, and tweak the adjusters 'till they (the pushrods) just stop turning, then back them off a whisker.
  4. Yeah, there's a debate about that - doing them while their cool versus hot, and stopped or with the engine running. Your advice certainly has the value of giving the rods real-world adjustments.
  5. The main function of valve clearances is to ensure that, at all operating temperatures, there is enough slack in the valve train to allow the valves to close fully without contact with the next component up the line (rocker. cam lobe, cam follower, whatever).

    As a general rule of thumb, valve clearances close up when hot so we generally need to set them slack when cold and, if set correctly, the clearance will approach zero as the engine heats up. This is why, where the correct setting is different for inlets and exhausts, the exhaust setting is, in every case that I'm aware of, larger than the inlet, 'cos the exhaust side gets hotter than the inlet.

    So for a bike like an old tech pushrod single, it is perfectly valid to warm the engine to normal operating temperature, or a bit above, and then set the clearances by trying to rotate the pushrods with the engine running as roarin suggests. This will give you a small positive clearance when hot (which is all that is needed) and the cold clearance is whatever it is. Betcha it'll be within a gnat's tadger of whatever the manual specifies.
  6. So I'm hearing votes for doing it hot. I guess I'll go with that.
  7. Look at it this way. It's an old tech single designed by a guy who probably died of old age before you were born, intended to be maintained with a limited tool kit, which 60 years ago might well have not contained feeler gauges, and built with Indian manufacturing tolerances.

    As long as there is some clearance when hot, but not so much that the ends get hammered off the pushrods, it'll be fine :D.
  8. :LOL: That's what I love about this bike. The engine was designed in the late '40s. Indeed, it makes my old SR500, whose engine was designed in the early '70s, seem so sophisticated. Both are so simple and so complicated by comparison with each other.
  9. Did you get the bits of chop stick out?

    I've never had a bike that could be adjusted this way, but I once had a 202 with solid lifters, double valve springs and the biggest valves that would go in. It had adjustable rockers, with a screw and locknut, which could be adjusted with the engine running. I used to adjust them when they started to sound a bit rattly (which could be every 100km if I gave it heaps, because it could bend the pushrods pretty easily) and the method explained above is exactly how I did it. With practice, I could whip the cover off, check 12 rockers and adjust 2 or 3, with an allen key and one spanner, and got the cover back on and drive away, in about two minutes. By the end, I didn't even bother switching off the engine. I did learn not to give it a rev while the rocker cover was off, but.
  10. Oil all over your face?
  11. No, but I figure they just burnt away! :) Did 200km afterwards and it ran fine.
  12. Oh yeah! And the underside of the bonnet, and everything under the bonnet, including the exhaust manifold, all over the floor, on the white walls of the garage... all over my clothes... the windscreen ...=D>
  13. HA hahahaha.
    now I know if I REALLY need to get my own back against one of my mates, I'll loosen their rocker cover screws to a few threads. :D
  14. Nah, you'd need to take it right off, and then have the engine idling, then give the throttle cable a good hard tug. I didn't think oil supply to the top was very good. At idle, it looks like there's hardly any oil gets up there at all. It's a different story at 3 grand, but.
  15. I had a 2-litre Escort for a while that used to do that all by itself as one of its quirks.

    Can't complain though. Paid $700 for it, it gave me 18 months (~30,000 kms) of fairly reliable commuting, cost me a cheapo immobiliser, a cam belt, a suspension bush and a couple of tyres and sold it for $350 when its oil burning became too embarrassing even for me. Went and handled bloody well too :D.
  16. My mates often like to give their cars a good boot off the lights anyway. I'm sure if I loosened the nuts to a few threads they would rattle off, then the rocker covers would fall off (or maybe not? my ones like to stick on pretty good), then the next set of lights, they'd go up in smoke, hahahaha. god damn that would smell.
    at the very least, the oil would piss out of the rocker covers due to there not being a very good seal without the nuts tightened, all it would take is a good boot.
  17. Careful with these fantasies Kernel - it often strikes me that if I was malevolent it would be so easy to do so much confusing damage to a bike :) Or maybe it strikes me as a matter of fear for my own bike.