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Gerrard 10-02-2019 04:21 PM

Valve Adjustment
 
I'll toss this out there and hopefully get a fix that I can tackle.
I was getting ready to work on belt install and noticed I might not be able to get to the valve covers easily with belt and shroud on, or not as easily at least.
So I 'kinda' did this before but didnt have much probs with it so I got out feeler gauge, got out blade that was .015 and 11 mm wrench ( sorry, only one I can find that will fit in there) but that bolt in there. or the 'bolts' are real tight and I started turning my bottom pully and of course everything started moving.
But my question is do I do the adjustment w/feeler gauge when valve starts on its way down and wants to make contact with bolt head and as it goes back up it will of course come back down after a rotation but on both sides I just try to keep the valve from making contact w/bolt head w/a .015 space inbetween them.

And does this make any sense?

jrd 10-02-2019 04:28 PM

Re: Valve Adjustment
 
You want to set valves when both cams are all the way down. Easiest way to get that is to turn the engine to TDC on the compression stroke.

RI-GravelyMod 10-02-2019 08:16 PM

Re: Valve Adjustment
 
Gerrand,

In the shops where I worked on all make of engines we checked or set the valve clearance using this method:

When the exhaust valve is fully open you check or set the intake valve clearance.

When the intake valve is fully open you check or set the exhaust valve clearance.

Trouble with Gravely and other engines is the pounding action of the valve stems into the lifters causes wear on both parts. This wear can cause an error when you check or set your actual gap.

RB

Gerrard 10-03-2019 03:01 AM

Re: Valve Adjustment
 
Quote:

Originally Posted by RI-GravelyMod (Post 12352917)
Gerrand,

In the shops where I worked on all make of engines we checked or set the valve clearance using this method:

When the exhaust valve is fully open you check or set the intake valve clearance.

When the intake valve is fully open you check or set the exhaust valve clearance.

Trouble with Gravely and other engines is the pounding action of the valve stems into the lifters causes wear on both parts. This wear can cause an error when you check or set your actual gap.

RB

Thanks, I'll try both methods and see wich one works best on this beast.
Sounds like these were made for leaded gas.

Gerrard 10-03-2019 03:14 AM

Re: Valve Adjustment
 
Quote:

Originally Posted by jrd (Post 12352847)
You want to set valves when both cams are all the way down. Easiest way to get that is to turn the engine to TDC on the compression stroke.

I cant hardly get thru my head that this is a dual cam engine. Im thinking the cams would be across left to right but they are front to back I guess. Weird, at least to me cause I think of DOHC on a big motorcycle engine like a 900 cc Kaw that I would watch my older buddies work on when I was a kid.

Ending my usual rambling, So when I manually turn it over as soon as the mag snaps I then gauge them both or do them individually as it snalp?
Im glad I stopped and got on here and posted because the ex side bolt or lifter was getting loose and if that would have somehow came out ( assuming it can ) I wouldnt have known what to do.
Thanks as usual
Mark Sr.

jrd 10-03-2019 08:17 AM

Re: Valve Adjustment
 
Quote:

Originally Posted by Gerrard (Post 12353075)
So when I manually turn it over as soon as the mag snaps I then gauge them both or do them individually as it snalp?

It's not critical. Anywhere around TDC will work.

Think about it. At the beginning of the compression stroke, both valves are closed. If they weren't, mixture would exit via a valve, rather than compressing. Same with the power stroke; if you open the valves too soon, you're not getting all the energy out of the combustion. So you have both valves closed for a substantial period of time before and after TDC.

Just turn the engine until TDC. mic/set both your valves. Don't be turning the crank while you're doing that. Once you're done setting them, it doesn't matter if you turn the crank, and you can button up the covers at your leisure.

Gerrard 10-03-2019 11:04 AM

Re: Valve Adjustment
 
Quote:

Originally Posted by jrd (Post 12353127)
It's not critical. Anywhere around TDC will work.

Think about it. At the beginning of the compression stroke, both valves are closed. If they weren't, mixture would exit via a valve, rather than compressing. Same with the power stroke; if you open the valves too soon, you're not getting all the energy out of the combustion. So you have both valves closed for a substantial period of time before and after TDC.

Just turn the engine until TDC. mic/set both your valves. Don't be turning the crank while you're doing that. Once you're done setting them, it doesn't matter if you turn the crank, and you can button up the covers at your leisure.

Thanks sounds great, I dont know why I seem to overcomplicate things just afraid I'll hear the ol'e " well didnt you do this/that?" lol.
But that sounds simple enuf, my way.

Alien5044 10-03-2019 02:55 PM

Re: Valve Adjustment
 
Forget "cams" etc. The only thing you need to determine is that the valve you are adjusting is closed.

Remove the spark plugs and rotate the engine until both valves on the cylinder you are working on, are closed.

Look into the cylinder with a light, if the piston is right there, rotate slightly to be sure it is at its all the way "up" and stop there. You can do those valves when both are closed when the piston is at the very top of the cylinder. Repeat on the other if this is a twin.

Recheck after some run time.

Take your time and be logical. You can do this.

Gerrard 10-03-2019 08:05 PM

Re: Valve Adjustment
 
Quote:

Originally Posted by Alien5044 (Post 12353319)
Forget "cams" etc. The only thing you need to determine is that the valve you are adjusting is closed.

Remove the spark plugs and rotate the engine until both valves on the cylinder you are working on, are closed.

Look into the cylinder with a light, if the piston is right there, rotate slightly to be sure it is at its all the way "up" and stop there. You can do those valves when both are closed when the piston is at the very top of the cylinder. Repeat on the other if this is a twin.

Recheck after some run time.

Take your time and be logical. You can do this.

Yea I get it but its a single cyl. T head and the main thing and why its seeming so complicated and I have so many questions is Im just now putting the whole tractor back together. 85% of it is still scattered everywhere.
Thanks Im goin out there right now and setting them. Just got home from work.

Gerrard 10-03-2019 10:02 PM

Re: Valve Adjustment
 
Well here's where Im at now. Got it to TDC without question and can touch the top of piston w/little finger, no wonder the plug is slanted because if it wasn't there would be no room for it at all.
But exhaust side went well and was pretty easy actually but the intake side seemed like it just didnt want to adjust. It ( the lifter/bolt) just wants to turn it seems.
Is there a way to turn the lifter/bolt all the way down and then just start working it upwards? I actually thought I saw the thing wobble once and thought
Wooooh". But it seems like it doesnt wanna go up or down.
Or does any of you know wich way does it turn to go upwards? Towards the front of tractor or back towards the operator?

I dont like asking for help all the time but Im so far into this thing I dont want to mess anything up and will stop before doing that.
I know its just a bolt thats in a hole but if I had to replace it I know I'd have to take the head off and all that jazz and I dont wanna do that again because Ive done it two times already and really dont wanna do it again.

Thanks to all of you
P.S. If this Gravely was gonna be for my use I would have just tuned it up when I got it and that would have been that.

jrd 10-03-2019 10:56 PM

Re: Valve Adjustment
 
Quote:

Originally Posted by Gerrard (Post 12353531)
Or does any of you know wich way does it turn to go upwards?

It's a right-hand thread.

You can tell by turning it, and then checking with your feeler gauges.

Gerrard 10-04-2019 03:29 AM

Re: Valve Adjustment
 
Quote:

Originally Posted by jrd (Post 12353579)
It's a right-hand thread.

You can tell by turning it, and then checking with your feeler gauges.

Well thats the problem, it doesnt seem to be going up or down wich ever way I turn it.
The exhaust side worked just fine.
I have turned that thing so much both ways Im afraid of rounding it off, the intake side that is.

jrd 10-04-2019 08:46 AM

Re: Valve Adjustment
 
Quote:

Originally Posted by Gerrard (Post 12353631)
I have turned that thing so much both ways Im afraid of rounding it off,

It's not clear why you think you're going to round off the head. It takes some oomph to turn it, because they don't want it backing out on its own, but a small open end wrench on there has always worked for me.

Is the head already damaged?

Alien5044 10-04-2019 10:17 AM

Re: Valve Adjustment
 
If your process worked OK on the exhaust valve, it should work exactly the same on the intake valve. I'm a little concerned that you said no matter how much you turn the adjustment nut, that it doesn't make any difference. That might imply a stripped nut or perhaps the rocker stud in the middle of the rocker, has loosened or pulled out. Check that to be sure.

Also, examine both valves to be sure that all the parts are present in both. Observe the valve actions by rolling the engine over by hand. Sometimes you can see what is wrong by comparing the actions of both valves in slow motion.

I might suggest that if you haven't already, you search YouTube for "small engine valve adjustment" videos just to confirm that what you are seeing and doing is the suggested process.

Sorry you are having these issues, I know it can be frustrating, but there IS an explanation. Just a matter of careful review of your engine's parts to see what might be wrong.

Gerrard 10-04-2019 12:15 PM

Re: Valve Adjustment
 
Quote:

Originally Posted by Alien5044 (Post 12353705)
If your process worked OK on the exhaust valve, it should work exactly the same on the intake valve. I'm a little concerned that you said no matter how much you turn the adjustment nut, that it doesn't make any difference. That might imply a stripped nut or perhaps the rocker stud in the middle of the rocker, has loosened or pulled out. Check that to be sure.

Also, examine both valves to be sure that all the parts are present in both. Observe the valve actions by rolling the engine over by hand. Sometimes you can see what is wrong by comparing the actions of both valves in slow motion.

I might suggest that if you haven't already, you search YouTube for "small engine valve adjustment" videos just to confirm that what you are seeing and doing is the suggested process.

Sorry you are having these issues, I know it can be frustrating, but there IS an explanation. Just a matter of careful review of your engine's parts to see what might be wrong.

Yea the video I watched is how I found out how to do it.
Its someone on here who has it up but I forgot his name, its a real simple procedure on the video and is anyway as long as everything works.


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