YM336D bad knocking engine

[murnere]

After working to gain access so I can turn over the engine, I can't help but thinking I'm doing something wrong. From what you all have posted, this shouldn't be as hard as I'm making it out to be, but I can barely get a socket on this nut and when I do, I can't move my strong arm at all.
From the pictures, can you tell if I'm in the right place? The red circle is where I can access the nut. The nut is way back and surrounded by everything.
Of course, it doesn't help that it looked like it would be a 17mm and I was too stupid to buy the whole set of deep wells since that would cost me $35 instead of $5 for just the 17mm.... when it turns out to be 19mm....I should have bought the set and saved the gas money and time. :confused3:

 

[CoyPatton]

I can not see much from your photos on my phone, but I suspect you are not on the right spot. Your crank bolt that you need to turn the motor over with will be in the center of the lowest pulley on the front of the engine.
Deep well and extension have been recommended because it is a dish type of recessed bolt. Follow your belt(s) down till they start to go back upward then look for a bolt head recessed inside that pulley.

Not a terribly good photo but the very center is where you want to be.

 

[CoyPatton]

Maybe a better photo

 

[Altona]

Hi Munere, Not sure what that bolt is in the picture but to rotate the crank and therefore everything else the bolt will be as CoyPatton has shown in the center of the bottom pulley. Not that I'm trying to make a big tough job harder it doesn't look to me like there is sufficient space to do it without taking the rad out of the way, perhaps there is but just be careful of the rad and your knuckles!

 

[clemsonfor]

After working to gain access so I can turn over the engine, I can't help but thinking I'm doing something wrong. From what you all have posted, this shouldn't be as hard as I'm making it out to be, but I can barely get a socket on this nut and when I do, I can't move my strong arm at all.
From the pictures, can you tell if I'm in the right place? The red circle is where I can access the nut. The nut is way back and surrounded by everything.
Of course, it doesn't help that it looked like it would be a 17mm and I was too stupid to buy the whole set of deep wells since that would cost me $35 instead of $5 for just the 17mm.... when it turns out to be 19mm....I should have bought the set and saved the gas money and time. :confused3:
View attachment 675148View attachment 675149

Always buy the set. You get to expand your tool collection.

 

[murnere]

I was finally able to get a 19mm deep well on the nut and successfully turn the engine. Cylinder 1 valves check ok. Cylinder 2 exhaust valve moves ok, but intake doesn't do anything. So I thought I'd start by making sure the push rod was straight and.....I dropped the lock nut down into the push rod slot. I saw it in there, but moved the rod and now I don't see it in there. I'm going to work with a magnet to find it. Unfortunately, that stops my valve work because I don't want to turn the engine over until I get the nut out.
I even told myself, "don't drop this nut," as I took it off the intake valve.
I couldn't have gotten this far without all of your all's help.

 

[clemsonfor]

I am lost here?? What nut did you take off where:confused3:. To adjust the valves you should be removing any nuts?

Ok nevermind I re read it. Looks like you took the nut off to pull the push rod out to check to make sure it was straight.

 

[winston1]

Not that it makes any difference setting the valves but after viewing one of your pictures I have to wonder if you possibly have a front auxiliary pto?

 

[murnere]

Yes, I took the nut off, unnecessarily, so I could check that the rod was straight. Boy, I wish I hadn't done that now.
Winston, I do not have a front PTO, but shortly after I moved away to college in '86, my father had hydraulics added to the tractor and a Great Bend FEL. I guess we didn't need a FEL as long as I was doing the shoveling/lifting. :laughing:

 

[CoyPatton]

Once you recover the nut, you need to get the motor so that it is in the compression or the power/fire stroke for that cylinder.
Reinstall the push rod and rocker arm but leave slack on the valve stem. Watch the push rods to determine when you are on one of those strokes. Them set your 0.006” gap. Now you can follow the Hoye link process yo get the correct placement of the cylinder piston to properly set the gap. It sounds as though you have only done 3 of the 6 valves to this point. Finish cylinder 2 then check cylinder 3. But it really sounds as though someone has played with valve or failed to tighten the rocker arm lock nut and vibration caused an issue.
Hopefully no other damage and no more accidental drops. But don’t feel too bad, if folks will not admit to such things, either they never do anything or they L** about others stuff also!

 

[sixdogs]

Is there a friend or someone experienced at this that could give you a hand or look over your shoulder?

 

[clemsonfor]

Is there a friend or someone experienced at this that could give you a hand or look over your shoulder?

He had someone that he showed the video too. Maybe one-day that guy can swing by to look.

 

[murnere]

My brother-in-law is very good with engines and only 1 1/2 hours away. He has helped me via phone calls mainly because he is a grain farmer and this is a busy year. Unfortunately, he has been ill recently and just tested positive for Covid. Hopefully in a couple weeks he'll be feeling better and then I'll see if he can help with this adjustment. Until then, I think I may be going to his place and helping him with the harvesting. I'm really starting to think that adjusting the valves is something you should first see someone do to get the feel. I am really using your all's suggestions and I appreciate all the help.
Today I bought a new magnet and I'm going to continue to try to get the nut out.

 

[clemsonfor]

Where did the nut fall? Just in the head by the rockers, you should see it.

 

[murnere]

it dropped down by the push rod (is that the rocker?). When I tried to grab it with a magnet, I pulled out the rod and hit the nut which dropped down another level. I'm guessing that leads to the cam shaft? I can't find a picture that shows all the nooks and crannies of the block, but it dropped a level below where the rod sits.

 

[Altona]

I can't really picture the size of the nut but it should be at the bottom of the "hole" probably sitting on the cam lobe. Unless it is very small I doubt it could fit through the gap beyond that. I do stuff like that all the time murnere. Take it slow and steady and with the right extending magnet it shouldn't be a problem to get it out of there. Good luck, buddy.

 

[CoyPatton]

I can't really picture the size of the nut but it should be at the bottom of the "hole" probably sitting on the cam lobe. Unless it is very small I doubt it could fit through the gap beyond that. I do stuff like that all the time murnere. Take it slow and steady and with the right extending magnet it shouldn't be a problem to get it out of there. Good luck, buddy.

Unfortunately, it could be most anywhere in that cavity. While one would hope it would land in a readily accessible spot like the cam lobe ad described, it could (and in my reality probably did) bounce/roll most anywhere. If a bit of probing with a magnet, a flexible one would be better, then it might be time to borrow a bore scope or worse case buy one. The bore scope should allow you to locate where it is and retrieve it.

 

[Altona]

Unfortunately, it could be most anywhere in that cavity. While one would hope it would land in a readily accessible spot like the cam lobe ad described, it could (and in my reality probably did) bounce/roll most anywhere. If a bit of probing with a magnet, a flexible one would be better, then it might be time to borrow a bore scope or worse case buy one. The bore scope should allow you to locate where it is and retrieve it.

You're probably correct CoyPatton. Again, I can't picture the size of the nut in relation to the gap available to fit through and roll around in. You would certainly know better than I. The scope is for sure the safest and best route to go. Hadn't considered that.

 

[sixdogs]

Did you turn the crankshaft while that nut was down there?

 

[murnere]

I have looked and can稚 see a thing. Bore scopes aren稚 too expensive, so I may add to my growing tool set.
Sixdogs, yes I did turn the cam. I moved it thinking I could continue checking the valves. When I felt a little tension I stopped, reversed a little and resumed probing with a magnet.