What am I looking at here?

[tunahead72 2,545]

I've been using my 1986 310-8 this spring for about a month, mostly to mow.  It's been fine mostly, especially considering it's overdue for maintenance.  But the other day I was mowing, and after about an hour the engine starting acting and sounding different, like it was "coughing / congested / having trouble breathing", smoking more than usual, and finally stalled and backfired.  I let it cool down for a few minutes, started it again, and got the same symptoms plus some burning/sparks (carbon?) at the front of the engine block, and then turned it off.  I cooled it down again, and then started it up and drove slowly back to the shed and let it cool completely.

 

On the theory that I might be looking at excessive carbon buildup in the combustion chamber, and since I haven't cleaned that area since 2012, I removed the head and took some photos.  It's pretty nasty looking:

 

 

 

 

As you can see, the area of the head near the valves has lots of carbon; the area over the piston has carbon deposits in the section near the exhaust valve, and is oily in other sections.  There are corresponding areas on the block, valves and piston.  There's also a "ridge" of black deposits at the top of the cylinder bore.

 

The intake valve is covered with black deposits (carbon?), the exhaust valve with white deposits (overheating?).

 

There's evidence of a little oil seepage around the head gasket in the right rear corner near the piston.  This is something I noticed a while back, and it's still there even after I flattened the head and torqued it properly with a new gasket (also back in 2012, torque checked several times since then).

 

This engine does lose a good amount of oil, probably 8 oz. or so every tankful of gas, maybe more.  I've never seen anything obvious that would explain that amount, and I don't know if it's leaking or burning the oil, probably a combination of both.  The engine was rebuilt in 2009, but I have nothing good to say about the guy who did that work, it's been losing oil since very shortly after he finished.

 

I don't think you can tell from the photos, but there's also a small but noticeable "divot" inside the cylinder bore, at the rear.  It's about 1" long and ¾" down from the top of the bore, generally in the same area that I'm seeing the oil seepage.  Maybe that's contributing to leaks around the rings?

 

And there's an area just in front of the block with a small amount of dirt and debris, maybe this is where I saw the sparks?

 

I installed a new spark plug earlier this month, but it's already badly fouled (carbon?).  The threaded area in the head is wet with oil, and the threads themselves may be stripped (something I noticed earlier):

 

 

 

I'm no engine expert, so my main question is: What does this all mean?  I could use your knowledge and advice here, any ideas you can throw my way will be much appreciated.  For now, my plan is to clean up the head and combustion area, flatten the head, put it all back together with a new gasket and torque the head bolts properly.  I'm hoping that this alone will solve the immediate problem, but I'm also considering a couple of other overdue maintenance items.  The points and condenser haven't been replaced since 2011, so I'll probably replace them soon (points gap is currently .018", set there to try to get rid of a worrisome noise, which made it a little quieter but didn't get rid of the noise completely).  I also plan to adjust the valves and clean the breather assembly soon; neither of these has been touched since 2012 (valves were set at .008" intake and .017" exhaust then).  I routinely clean the carb bowl and needles every spring, and I don't know of any reason why the symptoms I'm seeing would be fuel related, but I may give it a thorough cleaning anyway while I have it off for the valve and breather maintenance.  But like I said, I'm open to suggestions.

 

[JAinVA 4,636]

You didn't say how many hours.My guess is you need a rebuild.I bought a 310 that looked like that and I checked the bore.It was way over limits.

[tunahead72 2,545]

Good point...  I've owned this tractor since it was new, 1986 model bought in 1987.  I've used it regularly since then, almost completely for mowing about 1-2 acres every week, but also a little trailer hauling, pulling down small trees, that sort of thing.  The engine is original, was rebuilt .020" over in 2009, by a guy who chose to leave the area shortly after he finished my engine.  I wouldn't be surprised if it needed another rebuild, not because of the number of hours since then, but because he did such a horrible job on it.  I'll have to think long and hard about rebuilding it again, because I don't have the knowledge, and I don't know anybody local who I would trust.  Checking the bore sounds like a good next step, I've never done it and don't have the tools or the time, but I do have a service manual. 

[adsm08 3,249]

15 minutes ago, tunahead72 said:

Good point...  I've owned this tractor since it was new, 1986 model bought in 1987.  I've used it regularly since then, almost completely for mowing about 1-2 acres every week, but also a little trailer hauling, pulling down small trees, that sort of thing.  The engine is original, was rebuilt .020" over in 2009, by a guy who chose to leave the area shortly after he finished my engine.  I wouldn't be surprised if it needed another rebuild, not because of the number of hours since then, but because he did such a horrible job on it.  I'll have to think long and hard about rebuilding it again, because I don't have the knowledge, and I don't know anybody local who I would trust.  Checking the bore sounds like a good next step, I've never done it and don't have the tools or the time, but I do have a service manual. 

 

If you decide not to rebuild the engine and possibly replace the tractor I may be interested in it, engine issues and all.

[JAinVA 4,636]

Whatever you decide to do I would highly recomend an hour meter and regular oil changes every 20 hours.I decided to mount a Predator 13 horse on a 416 h to evaluate the transaxle.The engine is now on a 520h I have.There are options.

[tunahead72 2,545]

43 minutes ago, adsm08 said:

If you decide not to rebuild the engine and possibly replace the tractor I may be interested in it, engine issues and all.

 

I will keep that in mind.  I'm hoping to be able to nurse this thing along until the end of this mowing season, and then re-evaluate from there.  We'll see how that goes. 

 

41 minutes ago, JAinVA said:

 

Whatever you decide to do I would highly recomend an hour meter and regular oil changes every 20 hours ...There are options.

 

 

An hour meter sounds like an excellent idea.  Oil changes I'm usually very good about, usually 2-3 changes every year.  Last year was a major exception, looks like it might be biting me in the a$$ this year (I did change it a couple of weeks ago).

 

Thanks for your words of encouragement, guys.  This kind of thing does get me discouraged, especially with everything else that's going on in our worlds these days.  I would have given up on Wheel Horses a long time ago if I hadn't run into RedSquare back in 2011, still hoping to stay on the ride for another few years at least. 

 

[ZXT 2,401]

42 minutes ago, tunahead72 said:

 

I will keep that in mind.  I'm hoping to be able to nurse this thing along until the end of this mowing season, and then re-evaluate from there.  We'll see how that goes. 

 

 

An hour meter sounds like an excellent idea.  Oil changes I'm usually very good about, usually 2-3 changes every year.  Last year was a major exception, looks like it might be biting me in the a$$ this year (I did change it a couple of weeks ago).

 

Thanks for your words of encouragement, guys.  This kind of thing does get me discouraged, especially with everything else that's going on in our worlds these days.  I would have given up on Wheel Horses a long time ago if I hadn't run into RedSquare back in 2011, still hoping to stay on the ride for another few years at least. 

 

I certainly wouldn't give up on the tractor because the engine is tired. Rebuilding one is simple, but since you don't have the time, I'd keep my eye out for a good used runner. That would have you up and running fairly quickly, as swapping an engine is easy.

[squonk 43,820]

Yup engine is worn out. richmondred01 had a bunch of engines rebuilt and ready to go last year. I got a used k341  from him and am quite happy with it. 

[chex313 123]

On 4/25/2020 at 12:18 PM, tunahead72 said:

Good point...  I've owned this tractor since it was new, 1986 model bought in 1987.  I've used it regularly since then, almost completely for mowing about 1-2 acres every week, but also a little trailer hauling, pulling down small trees, that sort of thing.  The engine is original, was rebuilt .020" over in 2009, by a guy who chose to leave the area shortly after he finished my engine.  I wouldn't be surprised if it needed another rebuild, not because of the number of hours since then, but because he did such a horrible job on it.  I'll have to think long and hard about rebuilding it again, because I don't have the knowledge, and I don't know anybody local who I would trust.  Checking the bore sounds like a good next step, I've never done it and don't have the tools or the time, but I do have a service manual. 

Tunahead (Neighbor) your not alone. I have a 520H with at least 2 valve jobs done on it, that cost as much as new engine. I needed to run it for leaves 1.5 hours last fall, when my JD 1026R was down with a steering failure. It ran great, I turned it off and started it twice to make sure it was running and a week later could never get it running again. I couldn't figure out how to get the carb off to clean it. (Yikes) Anyway been debating whether to keep this tired engine or do either a HF Predator 13HP or 22HP...I live over past Collgeville (Zieglersville) and lurk here all the time.

 

What plays a huge decision is being able to get an engine(22HP) with a muffler for a 1/4 of what a muffler for the ONAN would cost...If I could even find one. Its got nothing but TLC since I got it for $500 years ago, but the first owner abused it, looked rough when I got it. 1500+Hours

 

I'll be following along with your thread....

 

 

Edited April 26, 2020 by chex313

[chex313 123]

On 4/25/2020 at 12:37 PM, JAinVA said:

Whatever you decide to do I would highly recomend an hour meter and regular oil changes every 20 hours.I decided to mount a Predator 13 horse on a 416 h to evaluate the transaxle.The engine is now on a 520h I have.There are options.

Jim did you have to cut the hood for the engine or for the attachment on the front? Is the 13HP enough beans for the 520 H? I would only be using it as a spare Tractor.

[JAinVA 4,636]

No stock hood would ever work with the crane boom attached.That particular hood is a 520 hood and a 416 hood stitched together.There is one photo in my original post of the Predator 13 and a 310 hood.That hood was pretty bad to begin with and needed to be modified to clear the carb controls and clearance for the exhaust.The 520 in my opinion only needs 20horses when running a 60" deck. That crane routinely picks 400lbs plus and horsepower isn't an issue.Couterweight is.In the photo

above the exhaust has been modified and should clear a stock hood.Here is how the stock hood needs to be shaped for the choke controls.

Edited April 26, 2020 by JAinVA

[chex313 123]

1 hour ago, JAinVA said:

Quote

 

No stock hood would ever work with the crane boom attached.That particular hood is a 520 hood and a 416 hood stitched together.There is one photo in my original post of the Predator 13 and a 310 hood.That hood was pretty bad to begin with and needed to be modified to clear the carb controls and clearance for the exhaust.The 520 in my opinion only needs 20horses when running a 60" deck. That crane routinely picks 400lbs plus and horsepower isn't an issue.Couterweight is.In the photo

above the exhaust has been modified and should clear a stock hood.Here is how the stock hood needs to be shaped for the choke controls.

 

Thank you, I'll go with a 13HP than, (48") Do you have a build thread on here for your Predator?

 

Edited April 26, 2020 by chex313

[JAinVA 4,636]

Actually I did one.Type in Predator 13 and its about 15 pages back.I used an Onan base plate to mount the engine to and came up with spacers to raise the crank center height to what an Onan is.By using the base plate I could align the PTP hoop so that a WH PTO is available.You will need a  crank spacer to bring the 1" diam Pred shaft to 1 1/8" size.If you need any additional help feel free to PM me.Luck,JAinVA

Edited April 26, 2020 by JAinVA

[chex313 123]

16 minutes ago, JAinVA said:

Actually I did one.Type in Predator 13 and its about 15 pages back.I used an Onan base plate to mount the engine to and came up with spacers to raise the crank center height to what an Onan is.By using the base plate I could align the PTP hoop so that a WH PTO is available.You will need a  crank spacer to bring the 1" diam Pred shaft to 1 1/8" size.If you need any additional help feel free to PM me.Luck,JAinVA

Thanks Jim, 

Ordered the shaft adapter off Ebay in case I needed it...   https://www.ebay.com/itm/1-to-1-1-8-inch-1-4-Key-Gas-Engine-Pulley-Crank-Shaft-Sleeve-Adapter-Predator/252430716490?hash=item3ac60b0e4a:g:1JwAAOSwOIlbza8~

 

and a new Hour meter..  https://www.amazon.com/gp/product/B07TYWYWFK/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

[JAinVA 4,636]

The PTO adapter is just what you need but the hour meter will need to get its own power as as I don't think there is a way to hook it to the Pred igntion.You can power the meter throug a switch but you will need to turn it on and off.I use an hour meter that works off spark pulse on the Pred.They have them on E-bay and they are very affordable.

[tunahead72 2,545]

Thanks for your replies so far, guys.  I was hoping to get more time over the weekend with this engine, but didn't.  I did manage to clean the head real good, and start flattening the surface until I ran out of sandpaper and broke the piece of glass I was using to support it.  Off to my favorite local hardware store later today.

 

I'm curious...  Most of you have suggested it's time for another rebuild, which doesn't surprise me.  But what I'm wondering is what exactly are you seeing from my photos that tells you it's time?  I understand how the rings could be bad and allowing oil up there, but what else?  Is it the heavy carbon buildup, the way it just stopped running (temporarily), the condition of the spark plug, the divot inside the cylinder, the noise, all of the above?  What do you think is actually happening inside this engine?

 

I know micing the bore is an excellent next step, and I'm thinking about picking up a telescoping gauge and micrometer so I can at least measure the top part of the cylinder without taking the engine apart.  I ran across a thread from @Mr Magoo that discusses some options, if anybody knows of any other inexpensive tools that might do the job reasonably accurately I'd love to hear about them here.  His thread is https://www.wheelhorseforum.com/topic/85211-c-120-auto-2/

 

I also took some time to figure out how many hours this machine might have.  It was... enlightening.  Under some reasonable assumptions about how often and how long I've used this tractor over the years, my most educated guess is that the engine has run about 650 hours since it was rebuilt in 2009.  That's disappointing but not surprising.  And I think it had about 1350 hours before it was rebuilt, which means this engine probably has around 2000 hours on it total.  That sounds like a lot of hours to me, but I don't really know how that compares to anybody else's experience, what do you guys think?  I will say I'm even more impressed with this series of Kohler engines than I've ever been, and that's saying a lot.

 

And finally, I took a look at a couple of isavetractors videos on rebuilding these old Kohlers.  I don't like some of the things he does, and I don't think I want to tackle a rebuild myself, but I do feel like I could at least remove the engine from the tractor and get it to somebody to look at more closely.

 

@squonk Thanks for the endorsement of @richmondred01, I've seen his ads and followed a lot of his posts, I think one of his engines would be an excellent "top shelf" solution to my problem.

 

And @chex313, howdy neighbor!  We'll have to get together some time after this Corona thing is past us.  I don't want to bash anyone publicly, but I'm curious about your valve job experiences and I'll probably send you a PM soon so we can compare notes a bit.

 

Later guys, I'm off to True Value.  Thanks again!

 

[bc.gold 3,406]

Is that pitting that I see on the cylinder wall.

 

 

[tunahead72 2,545]

Good question, and I don't know the answer yet, just haven't taken that close a look.  I'll do that this afternoon and let you know what I see.

 

[tunahead72 2,545]

2 hours ago, bcgold said:

Is that pitting that I see on the cylinder wall.

 

 

 

I took a look, and I honestly don't know how to explain that area.  After I took these photos the other day, I rotated the engine until the piston was at the top of the bore, maybe this was oil that got redistributed or something?  The entire bore seemed basically smooth and slightly oily just now, with just a hint of crosshatching.

 

I did notice that the divot I mentioned earlier is a little different than what I remembered from back in 2012.  It's actually a series of smaller, but deeper, voids in the bore.  This isn't a great photo, but it's the best I could do just now: