Rebuilt engine hard to turn over, but then loosens up?

Scrubcadet10

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  • / Rebuilt engine hard to turn over, but then loosens up?
Do you have a history with this engine? You simply can't have an engine that's running fine for 3 years let's say and then it gets hard to crank over and then you find the rod clearance tight and then change the rod and it's okay.
The only way this could be possibly possible is it it had been around the world and that rod was starting to weld itself to the crane but then you would have said and should take the metal off the crank with muriatic acid or whatever else and normally this wouldn't occur anyway as normally just to continue well the metal together and snap the rod.
I always said if you do this that long enough you will find something that's not possible that has occurred right in front so never say things can't be certain ways but this certainly doesn't make sense.
And frankly all this is way too Overkill and in debt and sounds like an engineer is doing it.. lol.
Changing comes my way, I simply see if it's mechanically sound with an external fuel source and if it runs or if it has been then I don't worry about that. I'm never going to turn it to the internals of it unless it snapped a rod or something like that and even then it's not worth it because I can just swap something else more quickly and cheaper.
I'm never going to bother to use plastic edge or two micrometer a rod on a mower.
Torque wrench is fine but anything past that is overkill.
He said in his very first sentence of his first post, he just overhauled the engine and the issue started occuring,.
 

unioncreek

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  • / Rebuilt engine hard to turn over, but then loosens up?
Do you have a history with this engine? You simply can't have an engine that's running fine for 3 years let's say and then it gets hard to crank over and then you find the rod clearance tight and then change the rod and it's okay.
The only way this could be possibly possible is it it had been around the world and that rod was starting to weld itself to the crane but then you would have said and should take the metal off the crank with muriatic acid or whatever else and normally this wouldn't occur anyway as normally just to continue well the metal together and snap the rod.
I always said if you do this that long enough you will find something that's not possible that has occurred right in front so never say things can't be certain ways but this certainly doesn't make sense.
And frankly all this is way too Overkill and in debt and sounds like an engineer is doing it.. lol.
Changing comes my way, I simply see if it's mechanically sound with an external fuel source and if it runs or if it has been then I don't worry about that. I'm never going to turn it to the internals of it unless it snapped a rod or something like that and even then it's not worth it because I can just swap something else more quickly and cheaper.
I'm never going to bother to use plastic edge or two micrometer a rod on a mower.
Torque wrench is fine but anything past that is overkill.
The whole story about why I over hauled the engine is in the thread. You'll have to read it all.
 

davis2

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  • / Rebuilt engine hard to turn over, but then loosens up?
I started with a HF 8 x 14,. Did quite a bit with it, just wasn't long enough. Bought the 10" Atlas for $300, it has a 48" bed. Right now I'm building a wood pellet mill (we heat with wood pellets) I don't get much time to work on it with everything else going on. I retire from work 18 months ago, had to go back to work, due to the economy.. I work for a farmer April thru Nov.

Bob
A pellet mill? Similar to a feed pellet mill? Interesting project, have you ever run a pellet mill?
 

unioncreek

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  • / Rebuilt engine hard to turn over, but then loosens up?
Yes, operated quite a few of them making alfalfa pellets. This is just a project I'm playing with. Need projects during the winter.
 

TobyU

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  • / Rebuilt engine hard to turn over, but then loosens up?
He said in his very first sentence of his first post, he just overhauled the engine and the issue started occuring,.
I just noticed that the title says rebuilt engine hard to turn over so obviously something wasn't done right and the rebuild or some parts got interchanged or had the wrong sizes to begin with.
 

TobyU

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  • / Rebuilt engine hard to turn over, but then loosens up?
The whole story about why I over hauled the engine is in the thread. You'll have to read it all.
Oh, I have certainly read it all! The problem is that was weeks ago. As We know This thread keeps getting revived because of all the notifications to people like myself that pop up in our email and then the link takes a straight to the last post and that is on a separate page which is unscrollable to get back to the very beginning and which would be very cumbersome and time consuming so we just start conversing at that point for getting a lot of what has transpired previously.
Sad, and maybe inefficient, but that is how it pans out.
I do remember now without going back and reading everything, the history on this. I was the one that kind of jumped your crap at the very beginning for rebuilding the engine in the first place and saying it was probably unnecessary.
Remember that big air filter discussion I said is the only way these things ever get worn out and dirt going in the intake etc?? Then, you assured me it wasn't head gaskets but rings and talked about how thin they were and how much excessive 3 to 4 times the limit of ring Gap when you took it apart..
I've never seen this and also find it hard to believe, I still think it was due to dirt being ingested past the air filter or bypassing it.
That's irrelevant at this point though.
So as I just told the other poster that since this was a freshly put together engine, if it was tight, then something was either installed incorrectly the first time, the wrong part, or some other way out of spec.
Now combining the information you gave me in a previous post which I believe was earlier today that when you change the connecting rod everything has been fine since, my theory is that connecting rod was the wrong one.
Did you take that same rod out of that same engine from the same position and put it back in to the same position??
If you didn't change any of the parts in the engine from when you took it apart to when you put it back together and you didn't change the positions of them like accidentally flipping something over or putting it in the wrong position, then there's no way a clearance can change.
But as I said earlier, sometimes things that just can't happen do.
I've stated before that I'm not big on people taking these engines apart because it's almost always a waste of time and money because there are cheaper alternatives but along this path of things that aren't supposed to happen that do..
Just in the past 18 months I had one of these same engines that ran fine but had a terrible knocking noise in it.
I became so intrigued as to what it could be that I decided to spend the hour or so to take it apart and look around.
I thought for sure I would find something obvious.
I had to complete block disassembled with the crank out both Pistons rods camshaft and everything.
Everything looked absolutely perfect.
Nothing was loose on disassembly and the rods weren't loose or floppy and had no signs of wear or damage.
Now, I don't claim to be an expert on these because I don't mess with them because I think it's a waste of time but I do have some pictures of a couple of little scratches on the Piston skirts but nothing from all my years of engine building autos and everything else let me to believe there would be a problem. Wrist pin had a little play in it but again nothing that should make a noise like I was hearing which was kind of a mid-range knock definitely not top in but not bottom in big end of rod sound.
So now the kicker.
I put it back together and fire it up and it sounds exactly like it did before.
That's not unexpected because I didn't do anything and didn't change anything and didn't find anything.
So I run it for maybe a minute or two.
Then I started once or twice again over the next two or three days but never run it for over another minute or so.
Then, I started up and drive it about 100 ft to load it on a trailer and it's still making the same sound.
I shut it off to get the trailer ready for about 45 seconds.
I started back up and as I go to load it on the trailer after 12 seconds run time the noise goes away!
I rev It up I'll let down I stop and start it several times. The noise did not come back!
I loaded on the trailer and haven't seen or heard from it since so I don't know what happened but it was so quiet when it left that if you had not known there was a problem you would never suspect anything.
Weird.
 
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  • / Rebuilt engine hard to turn over, but then loosens up?
I have a JD D140 lawn tractor with a B&S 22 hp V Twin engine. I just over hauled then engine and replace the rings because of oil loss. I reinstalled the engine and cranked it over a number of time trying to start it. Wouldn't start got that figured out and started it and ran for a while at varying speeds to break it in. I tried to start it yesterday and it wouldn't turn over. Thought the battery was low on charge. Put a booster battery on and it would crank over. To the top off so I could get to the flywheel. I put a socket on it and it was hard to turn over for a couple of revolutions then got easy. Cranked it over and it started right up. Today it did the same thing. Runs good once I get it started. Any suggestions on what I should do? The first thing I thought was I got the wrong rings, but the end gap was within specs and it cranks over easy after a couple of revolutions. Is it just that tight and will loosen up over time?

Bob
adjust valve clearance intake 5-7 exhaust 7-9 sometimes the camshaft needs replaced because of decompresion portion is not working
 

Jcpowered

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  • / Rebuilt engine hard to turn over, but then loosens up?
Check your valves if they are adjustable . They sound like they are way to tight.
 

TobyU

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  • / Rebuilt engine hard to turn over, but then loosens up?
adjust valve clearance intake 5-7 exhaust 7-9 sometimes the camshaft needs replaced because of decompresion portion is not working
That's .004-.006 on both valves on the Briggs OHV twins...per Briggs and Stratton.
The singles are .003-.005 intake and .005-.007 exhaust. Both adjusted at 1/4inch past TDC of compression stroke for each cylinder.
 

mtd46

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  • / Rebuilt engine hard to turn over, but then loosens up?
I have a JD D140 lawn tractor with a B&S 22 hp V Twin engine. I just over hauled then engine and replace the rings because of oil loss. I reinstalled the engine and cranked it over a number of time trying to start it. Wouldn't start got that figured out and started it and ran for a while at varying speeds to break it in. I tried to start it yesterday and it wouldn't turn over. Thought the battery was low on charge. Put a booster battery on and it would crank over. To the top off so I could get to the flywheel. I put a socket on it and it was hard to turn over for a couple of revolutions then got easy. Cranked it over and it started right up. Today it did the same thing. Runs good once I get it started. Any suggestions on what I should do? The first thing I thought was I got the wrong rings, but the end gap was within specs and it cranks over easy after a couple of revolutions. Is it just that tight and will loosen up over time?

Bob
Bob
B&S i think also makes motors for the John Deere mowers sold at lowes i have one with only 300 hrs and it started smoking and using oil
How many hours was on your before you overhauled it
One Guy said he had one that was smoking and using oil and he put T4 rotella 15 w 40 made by shell have you heard of this or tried it?
I know thats not the problem you have but thought you might help solve my problem.
It seems the B&S motors are sorry engines
I cn,t even find anyone to overhaul mine they claim they don,t have the equipment to bore the block but i wouldn,t think wirth only 300 hours it would need boring what do you think?
 
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