Should I keep going further right now or see if it’ll crank?

[Alexander1997]

On my 1948 MM Z, I spent pretty much all day yesterday piddling with it. I removed the rocker arms and gave them a very good cleaning, scrapped off the remains of the old valve cover gaskets and I can take my hand and push each valve and feel it move. They were stuck when the tractor was bought.

I cleaned the grit from between the jugs and I have a very nice original manifold ready to replace the old cracked one.

Here’s my question / concern.. the person helping me says to NOT put the manifold on yet and see if it’ll crank and how it runs. He’s pushing me to remove the engine head, possibly get it surfaced, remove all valves and clean them and readjust them.

I am grateful to have help on this tractor I bought and this is my first restoration ever, which is why I need opinions, because I’m scared he going to get annoyed with me, but my thought as of right now is, why keep digging further when I’ve got the valves free.. Just replace the gaskets, put the new manifold and rebuilt carburetor back on, put the rebuilt magneto on and see if it’ll crank.. See if it leaks or knocks, then if it does, it’s time to shut it down and start digging.

So my question is, if this was yours at this stage, would you take his advice and remove the head, remove all valves or try to get it all together right now and see if it’ll crank and troubleshoot?

The engine seems to have strong compression and it turns over easily with the hand crank.

For what it’s worth, I love this tractor and the goal is a full restoration, eventually.

Thanks!

 

[JOCCO]

Tough one or 50/50, it would help if you knew its history like running good 2 years ago. Another way to look at it is if you go all through it is done! Only thing I ran into some of those had various gasket leaks and had to come apart to fix like gasket under jug. Even though they run good.

 

[Alexander1997]

Tough one or 50/50, it would help if you knew its history like running good 2 years ago. Another way to look at it is if you go all through it is done! Only thing I ran into some of those had various gasket leaks and had to come apart to fix like gasket under jug. Even though they run good.

It was running 15 years ago and running strong according to my friend. He parked it and it sat idle from 2009-present, so I’m torn

 

[molinegb]

Fire it up. No sense creating more problems if not necessary. You can't resurface head as it is not flat.

 

[JOCCO]

I don't think you have to much to lose either way. It is a gamble just like buying a lottery ticket. I think if it sat that long and was stuck, I would be more worried about stuck ring issues.

 

[yonson]

I watch a lot of TV programs involving vehicles that have sat for years. The mechanics invariably try to start the engine in order to evaluate its mechanical condition after sitting so long. That's what I would do - you can't finish a job without knowing what you have & as they say, "if it ain't broke, don't fix it".

 

[G1000VISTA]

I bought a MM UTU out of SD that sat for years in a shed then two years in the " big blue roof". One exhaust valve was stuck, The oil had dried out in the block. I free'd the valve, Cleaned the crankcase , filled it and spun it over. If I was you, I would light a fire in it. If you know the valves are free, and such you wont be out much.

 

[Rich'sToys]

I agree, and posted as such in your other thread.

 

[Alan K]

As long as the inside of the motor looks decent without obvious rust in places, lube it up and run it. I would pull the coil wire off before you start it and turn it over with the starter several revolutions to get the oil moving through the engine. It should start to come up on the gauge. Then put on the coil wire. I do that with everything that has been sitting for a long time and after an overhaul.
If you get it running, pay attention to the rocker arm oilers. If they aren't dripping oil, take a small vice grip, lock on them and gently rock them back and forth until they feel a little limber and move up and down a tiny bit. They are small nails through the copper tube and "sealed" with felt. Had to do that on my cousins ZA which sat for several years. They are all oiling well now.

 

[DPittman]

The ones I have got running after sitting for a time I take them to about where you are now, put them back together and see if they will run. When I get it running I’ll drive it around for a total of 5-6 hours run time. it makes sense to me that after that you will have a more accurate compression check as well as finding noises that shouldn’t be, possible oil pressure problems as well as leaks, and possible drivetrain/steering problems. Start writing stuff down and go from there. Do what Alan said, make sure you have lubrication and coolant. Some pics would be nice

 

[MMDEL]

I agree with most everybody else, If it ain't broke don't fix it. If you have deep pockets and money to spend for parts you don;t need, and want to throw away parts that are good. Go ahead and tear it all apart. you will get an education. But I myself want to see and diagnose an engine if it can run before I start so I have a idea of what is wrong with it. Your friend obviously dose not know anything about a Z engine, the head, as already has been stated can not be resurfaced. It is not flat inside. And I have never seen one that needed to be. You have to have the manifold on to run it so you have intake and carb. If the old one is still on. Leave it. If it starts, it would be s good idea to put a good product in the fuel tank to free up and clean the rings. But this won't happen in 15 minutes. You should run it like was said for hours. I like to put them to work. Check for smoke and the color of it. Power,noises, leaks, and anything that don't seem right. Then you realty know what you have to fix.

 

[random_farmhick]

Fire it up. No sense creating more problems if not necessary. You can't resurface head as it is not flat.

You can most certainly resurface the head, although its very much time consuming, and much more expensive than a regular cylinder head.

 

[molinegb]

You can most certainly resurface the head, although its very much time consuming, and much more expensive than a regular cylinder head.

Be a total waste of time. Heads are dime a dozen an never gave any seating issue. Low compression motor so head gaskets usually reused.

 

[random_farmhick]

Be a total waste of time. Heads are dime a dozen an never gave any seating issue. Low compression motor so head gaskets usually reused.

I'm not saying that they are not cheap, I'm just saying that they can be resurfaced. I also would never reuse a head gasket if I can buy a new one.

 

[DPittman]

I got my brothers R unstuck and in the process of that, I wound up pulling the head. Putting it back together I used the old head gaskets just to see if it would run and they’re still on it running good with no leaks. LP head

 

[Cliff Nelson]

On my 1948 MM Z, I spent pretty much all day yesterday piddling with it. I removed the rocker arms and gave them a very good cleaning, scrapped off the remains of the old valve cover gaskets and I can take my hand and push each valve and feel it move. They were stuck when the tractor was bought.

I cleaned the grit from between the jugs and I have a very nice original manifold ready to replace the old cracked one.

Here’s my question / concern.. the person helping me says to NOT put the manifold on yet and see if it’ll crank and how it runs. He’s pushing me to remove the engine head, possibly get it surfaced, remove all valves and clean them and readjust them.

I am grateful to have help on this tractor I bought and this is my first restoration ever, which is why I need opinions, because I’m scared he going to get annoyed with me, but my thought as of right now is, why keep digging further when I’ve got the valves free.. Just replace the gaskets, put the new manifold and rebuilt carburetor back on, put the rebuilt magneto on and see if it’ll crank.. See if it leaks or knocks, then if it does, it’s time to shut it down and start digging.

So my question is, if this was yours at this stage, would you take his advice and remove the head, remove all valves or try to get it all together right now and see if it’ll crank and troubleshoot?

The engine seems to have strong compression and it turns over easily with the hand crank.

For what it’s worth, I love this tractor and the goal is a full restoration, eventually.

Thanks!

I worked on a ZB last summer that sat for 30 years (inside). Similar to what you are describing. Freed up a couple stuck valves, squirted some oil on top of the pistons, and turned ok with the crank. At that point I put a battery in it and spun with the starter to see if it built oil pressure, which it did. Put spark plugs in and spun again listening for signs of valves leaking. All sounded good so rebuilt carb, replaced points/condenser, added gas, and started right up. I wouldn't take any more apart until you can prove that it needs to come apart.