ironhead valve adjustment

[martyp]

Hi guys looking for a bit of advice please. I've already looked at the stickys on xlforum and watched a couple vids but I'm still stuck!

Checking the pushrod adjustments on my 79 ironhead (points ignition) and I can't seem to adjust these things right. For example when I rotate the rear wheel so the rear exhaust valve is fully open and check my front exhaust valve it feels too tight with zero freeplay. I try to adjust the top screw after loosening off the locknut and it does nothing. The adjuster nut doesn't spin freely like in the demo vids and it doesn't seem to loosen the play in the pushrod either. I'm confused!! Some of the pushrods spin super easy when they are open but don't budge a bit when they are closed. But the front exhaust remains solid no matter what its position. Can anyone give me an idea of what's happening here? Thanks

[popelli]

the push rods should when valve is closed spin freely with no vertical movement

once you have lossened off the lock nut the adjuster that screws into the cam follower needs to be adjusted to get the correct zero end play

you need 3 spanners and as many hands to hold everything in place when you tighten up the lock nut once everyting has been adjusted

[martyp]

Thanks for replying,

Yeah that's what all the stickys and vids say. The thing is I'm finding that the pushrods are super tight when they are closed (down) but then loosen up when they open (fully up)??
The front pushrod ( exhaust) just won't free off. I've tried loosening the locknut and it frees off but the adjuster screw seems stuck fast to the point I have to use a spanner to move it and it doesn't matter how much I try to turn it anti clockwise to loosen it off it doesn't seem to get loose so I can feel slack in the pushrod! The rear wheel won't turn forward now at all (in 4th gear as per sticky) and I'm worried I'm doing damage by trying to sort this!

Ps - the bike keeps fouling plugs from running too rich and after second set of plugs and mix adjust on the carb this was my next thing to inspect

[Destralo Roach]

Ok, I think your using Brit terms to describ what your doing and they are diferent than Yank terms, Need some pics of said pushrods and so forth.

First thing you should do is make the push rods loos, then keep the bike in fourth gear and have it ON THE GROUND.

In order to adust the pushrods corectly, you move the bike on the ground in gear through the compression stroke to the cillender you are trying to adujst, once you adust the Ex and Intake of that cil, then push the bike forward to the next cill top dead center comp stoke, both liffters or Tappets will be in the down position, you might have to push them down your self to get them to seat, then adust them.

They should spin freely but only at TDC for that cill, the other cill will be on the Intake stroke or ex stroke, if you do this with the bike off the ground, you will not quite get it rihgt.

Hope that helps and feel free to P.M. me if ya have any more ???

....Roach.

[martyp]

Had a go there rolling the bike on the ground and that did help.
Adjusted all the pushrods individually only when they were fully closed and so they just move a bit no up or down play. Hopefully I did it right! Thanks guys

[ckunsman89]

I always adjust mine with the engine hot. I know the manual says to do it cold, but when one of these motors comes to operating temperature, the pushrods stretch a little, and may not allow the valves to close completely. Just the way I adjust solids, and it has always worked for me without any problems.

["Whitey Ford"]

^^^^ but when the motor cools down will it put stress on the valves by keeping them from closing fully? Seems that would put some strain on them and not help it in the long run. Im not questioning it just asking. Hell I just adjusted mine for the first time like 2 weeks ago. However I didnt do them like Roach said I kept it in the air the whole time and just ran through the gears. Then adjusted one by one when the opposite was fully open. It runs way better now but I know Roach knows his shit so i may re-do them now.

[ckunsman89]

Originally Posted by "Whitey Ford"

^^^^ but when the motor cools down will it put stress on the valves by keeping them from closing fully? Seems that would put some strain on them and not help it in the long run. Im not questioning it just asking. Hell I just adjusted mine for the first time like 2 weeks ago. However I didnt do them like Roach said I kept it in the air the whole time and just ran through the gears. Then adjusted one by one when the opposite was fully open. It runs way better now but I know Roach knows his shit so i may re-do them now.

No sir, if you adjust them hot, when the pushrods are fully expanded, they will shrink as they cool, and will in turn be a little on the loose side, but no more than a thousanth or two. Obviously, you do not want a pushrod that is way too loose, as that causes unwanted noise and excessive wear on pushrods. I have found that because of the noisy nature of the solid tappet ironheads, most people overtighten the pushrods to quiet them down. This will hold the valves open just enough when at temp that the valves do not contact the seats long enough to dissipate heat to the head, and will, in turn, cause burnt exhaust valves, hard starting when hot, and poor low end performance. That's my reasoning, I am not saying that it is the only way to adjust them, but it has proven to work for me.