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Discussion Starter #901
What method did you use to decarbon the heads?

Sent from my SCH-I605 using Tapatalk
First, as recommended by Kohler, a wooden stick, which easily removed the heavy deposits. Then, a little carb cleaner and a scotchbrite pad.

I also cleaned the back of the intake valves with a small wooden stick, just turned the engine over until they were open, scraped of the crud, blew it out with compressed air.

Sheldon
 

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Sheldon,

Are you planning to re-torque the head bolts now that you've heating things up and let them cool? I've heard many folks recommend it.
 

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Discussion Starter #903
Sheldon,

Are you planning to re-torque the head bolts now that you've heating things up and let them cool? I've heard many folks recommend it.
Kohler does not make any comment on that, but Kohler has changed the design of the head gasket. The new head gasket is "softer" and "smoother" than the old one.

The torque spec for the head bolts is 15-20 ft-lb. I went with 20........

So no, at the moment I have no plans to re-torque them.

Sheldon
 

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Discussion Starter #904 (Edited)
UPDATE:

So the 18GLX has had a very minor, intermittent problem for a while now. Seems to be vapor lock.

Here is the story, and the fix?

The tractor starts right up, any weather any time, and will run indefinitely without incident or hesitation.

BUT, if it is hot outdoors, I mean 80/85 plus, and I shut the tractor off for about 10 minutes, like long enough to empty the bagger cans, I get the following:

The tractor starts right up, but after about 30 seconds to 1 minute, it will act fuel starved. Pulling out the choke will keep it running, but rough. After about 1 minute, no more than 2, it settles down and runs fine. It will then run fine indefinitely once again. Shut off and allowed to cool down fully, it always starts without issue and runs fine.

Obviously the duration of this problem prevents any real time testing of things like the fuel pump, but I had a good spare and changed it some time ago for good measure - no difference.

The fuel tank is clean, the fuel is fresh, the fuel filter is new, the fuel line is new, the engine cooling fins are clean and clear, the carb is new and clean.

So here is what I did:

Relocated the fuel filter from its original location right near the fuel pump. I moved it all the way back along the frame to near where the fuel line comes through the frame channel.

Replaced the small factory fuel filter with one of those larger ones - also Kohler brand.

I insulated the fuel line from the filter to the fuel pump.


So far, several fairly hot mowing days, no troubles, we will see. So was the fuel boiling out of the small fuel filter? Why now after all these years?

The challenging and frustrating thing about this is that this problem never occurred in nearly 18 years of use. Then just out of the blue, in this very intermittent way, with no changes to the equipment, it has this problem.

Photos soon......

Your thoughts,

Sheldon
 

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Quality of fuel is all I can think of . I know you as particular as I am with fuel , but maybe the station received a bad batch they aren't even aware of ? If they received E15 or higher instead of E10 , I would assume the alcohol content would vaporize quicker the gasoline .
 

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Discussion Starter #906
Quality of fuel is all I can think of . I know you as particular as I am with fuel , but maybe the station received a bad batch they aren't even aware of ? If they received E15 or higher instead of E10 , I would assume the alcohol content would vaporize quicker the gasoline .
I questioned the fuel as well, but the problem has persisted over several seasons and multiple fuel purchases. So it would have to be a wholesale change in the fuel formula to be a fuel problem.

In 21 years the tractor has always been run on SUNOCO mid premium or BP premium, only one event I concluded to be fuel in all that time.

I will get back to you about your other question shortly........

Sheldon
 

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UPDATE:

So the 18GLX has had a very minor, intermittent problem for a while now. Seems to be vapor lock.

Here is the story, and the fix?

The tractor starts right up, any weather any time, and will run indefinitely without incident or hesitation.

BUT, if it is hot outdoors, I mean 80/85 plus, and I shut the tractor off for about 10 minutes, like long enough to empty the bagger cans, I get the following:

The tractor starts right up, but after about 30 seconds to 1 minute, it will act fuel starved. Pulling out the choke will keep it running, but rough. After about 1 minute, no more than 2, it settles down and runs fine. It will then run fine indefinitely once again. Shut off and allowed to cool down fully, it always starts without issue and runs fine.

Obviously the duration of this problem prevents any real time testing of things like the fuel pump, but I had a good spare and changed it some time ago for good measure - no difference.

The fuel tank is clean, the fuel is fresh, the fuel filter is new, the fuel line is new, the engine cooling fins are clean and clear, the carb is new and clean.

So here is what I did:

Relocated the fuel filter from its original location right near the fuel pump. I moved it all the way back along the frame to near where the fuel line comes through the frame channel.

Replaced the small factory fuel filter with one of those larger ones - also Kohler brand.

I insulated the fuel line from the filter to the fuel pump.


So far, several fairly hot mowing days, no troubles, we will see. So was the fuel boiling out of the small fuel filter? Why now after all these years?

The challenging and frustrating thing about this is that this problem never occurred in nearly 18 years of use. Then just out of the blue, in this very intermittent way, with no changes to the equipment, it has this problem.

Photos soon......

Your thoughts,

Sheldon
Sheldon,

Possibly the coil? They tend to stop working when heat soaked, mine would work fine but when I shut down for a few minutes the coil would get heat soaked and refuse to restart until the engine cooled significantly. Perhaps yours is in the early stages of breaking down?

.
 

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Interesting Sheldon. Those of us who for one reason or another buy older tractors with little idea of how their life has gone to date, are often confronted with these mysteries. I'll sure keep track of anything you post about this.

One other thing. I know you said picture coming. I'm very interested in specifically how you insulated the gas line from the filter to the fuel pump. Do expand on that, please.
 

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Discussion Starter #911
So, the computer had a few problems last week, all fixed, no data lost, thanks to my great IT guy Adam.......

My mystery vapor lock problem seems to have been cured by the changes to the fuel line.

I did all these changes at once, so I'm not sure which was the cure, or if all were necessary.

I insulated the fuel line from my new filter location to the fuel pump using two products from McMaster Carr:





I changed the fuel filter to the larger one shown here. The smaller one is what came on the tractor 22 years ago and they have worked fine until this problem showed up:



I relocated the fuel filter to this location:



I cut the very tall grass in the hot weather Saturday mid day, had to stop the tractor numerous times to empty the bagger, no restart problems in 90 degree heat.

Sure would like to know what changed to require this modification after 18 years of trouble free operation? I'm temped to remove the insulation to see if the fuel filter size/relocation alone corrected the problem.

Your thoughts?

Sheldon
 

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I've followed your improvements to stave off future issues . That being said , you have a much more analytical mind than I could hope to have . But , following your improvements , I may possibly have an answer . Your improvements involved raising the RPMs and increasing the load on the engine with extra blades and with the grass vacuum attached . Would this also increase the engine temperature ? Obviously you would have had to check before and after to have an answer . That's all I can think of . I've already installed the larger filter when I replaced my fuel lines . Just for piece of mind , I'll be installing the insulation next summer when I change the filter . Congratulations on fixing the problem .
 

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Discussion Starter #913
I've followed your improvements to stave off future issues . That being said , you have a much more analytical mind than I could hope to have . But , following your improvements , I may possibly have an answer . Your improvements involved raising the RPMs and increasing the load on the engine with extra blades . Would this also increase the engine temperature ? Obviously you would have had to check before and after to have an answer . That's all I can think of . I've already installed the larger filter when I replaced my fuel lines . Just for piece of mind , I'll be installing the insulation next summer when I change the filter . Congratulations on fixing the problem .
That is a very good point. The RPM's have been higher for a longer time and in theory the higher cooling fan speed should offset any increased temp related directly to the RPM's. BUT the added load of the dual blades, at any RPM, may indeed be increasing the operating temperature, just enough, especially in hot weather. I still suspect the small fuel filter was becoming heat soaked, and this idea fits right into why or how that might have been the case.

Thank you for your thoughts,

Sheldon
 

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I appreciate the pictures Sheldon. I've had no problems like this but have been concerned about the gas line coming in through that area and how hot it is in there.

Please name the insulating sleeve you are using. Perhaps a McMC item number?

IF I'm guessing the origins of this problem coming up after so many years w/o a problem. my mind goes to the difference in the gasoline supply from years ago.
Since I've sworn off gas containing ethanol I've had no issues with any of my tractors. They've all been starting easily even after sitting idle for long times.
Just brought 32 gallons home from upstate NY where it is sold at pumps!

BTW, nice shot of the muffler set-up on that side of the engine. As you know I'm also interested in that.

Do you happen to have a shot of the one on the oil filter side?

Thanks.
 

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Discussion Starter #915
Al,

It is surely possible that the brand of fuel I used has experienced some sort of change in formula, but for the last decade the tractor has only been run on BP/AMOCO premium (BP bought AMOCO years ago and still advertises there premium fuel to be the AMOCO formula). For the decade before that, the tractor ran exclusively on SUNOCO mid premium. In those days we had a SUNOCO station so close I actually drove the tractor to the station to fill it up.

I have only had one problem in 20 years that seemed to be bad fuel. Keep in mind that the problem in question only happened on a hot restart in hot weather. No amount of idling, or no amount of running time would experience the problem if the tractor was left running? In fact, when it starting happening I experimented with simply leaving the tractor idle while I emptied the bagger, never had a problem if I left the tractor running..........

Thru this whole problem over the last two years the tractor starts right up, idles fine, and runs fine in cooler weather. Recently it did have some "popping" or "missing", or roughness running at no load, but the recent removal and cleaning of the cylinder heads has corrected that.

I surely agree that non ethanol fuel is better, no easy sources around here that I know of, but I do also believe that the quality of the additives is the key - BP and SUNOCO are known among performance car enthusiasts to be of higher quality, and they don't use the pipelines to deliver their finished product so the quality control is better.

The inner sleeve is ceramic braid, 3/4" size, McMater Carr #88175K3. The outer sleeve is aluminum, McMaster Carr #7293K2, also 3/4" size. I could have used smaller sizes, but this worked ok. The inner sleeve is actually folded around after inserting the 1/4" fuel line.

I am still leaning to the idea that the main problem might have been the small fuel filter, don't know?

I used a smaller size of the ceramic sleeve on the starter wire years ago when I changed the exhaust.

I will post more pictures of the exhaust, and will sent you them directly as well.

Sheldon
 

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Discussion Starter #916 (Edited)
UPDATE:

Where does the time go?

Life has been very busy this last year. And while I have followed the forum some, and replied to a few threads, my own GRAVELY activities have been minimal.

The problem with what seems to be heat induced vapor lock on the fuel system is better, but not perfect - but there are more changed conditions that may shed new light on that, or confirm prior speculation. More on that in a bit.

There are big changes in the works for us, the wife and I have purchased our retirement home and we are in the process of moving. As previously predicted, the new house is much smaller, but is on more land. Which will change my needs regarding the 18-GLX.

Also, for the first time, I have purchased a trailer able to transport the GRAVELY. Currently I am caring for two lawns, the old house and the new one.

The new house sits on 2.3 acres, flat, wide open, but with a few trees. More than twice the mowing of the old house, only one acre, and filled with pool, large house, large detached garage......

It will be a month or two before we complete the move, and the old house will require some "maintenance" on the exterior before it goes up for sale.

Out of practical necessity I have removed the blower/bagger system from the tractor as it is not practical or necessary at the new house. The primary reason we bagged clippings here was the swimming pool. Also years ago we had a number of trees, so the bagger was great for leaf cleanup in fall.

Without the bagger in place, the dual blades on the 50" deck are proving to be amazing at some very tall grass. An exceptionally wet summer has made the grass at the new property thick and fast growing. No trouble knocking it down with great looking results. Also, no vapor lock problems since I removed the bagger? Despite some very hot weather and long mowing sessions with a few breaks that were similar to my bagger emptying breaks. Too much load? Not enough air flow? Not sure.

Not sure yet what the leaf cleanup situation at the new house will be like, but a different solution from the three can bagger may be necessary. Since bagging clippings is simply not going to be necessary at the new property, a Trac Vac may be a better solution than the GRAVELY blower mounted on the tractor.

Also, while the 50" deck does mow it in a reasonable amount of time, I am considering a wing mower for the large back yard if I can find one.

I think that would be a better solution than a 60" deck, the front yard has some tight areas where the 50" deck is perfect. A wing mower would make short work of the large back yard, and the could be easily dropped for cutting the front.

Work and family have kept me very busy. I do hope to make it to the mow-in, maybe even with the tractor, we will see.

More later, and I will post some pictures.....

Sheldon
 

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Good to see a post from you Sheldon. I dropped off of here about a year ago as well. I've been reading but not saying much lately. All of this is simply due to being overwhelmed with work and life in general.

My 8183 PTO has ceased to work. It's been handling the Full load up in VT for almost a decade and that is a tough, rough, job. Further unlike you, I have little knowledge of its prior life - other than the certainly it was re-powered with a newerM18s than the frame and transmission. Since the 3rd mow of the season, the 816, also powered by an M18s, has been the mower up there. I brough the 8183 down for needed push and pull around the MA homestead. My 20G sits waiting to be brought back including the steering brakes.

I can see how your new property will require different from the GLX. I'll look forward to reading about it as it develops.

Thanks for posting the Mcmaster SKU #s for the gas-line insulation upgrade. I'm doing it to all 3 Kohler Magnum Twins I run. in my opinion that area is just too hot for the gas to be traveling through.

I hope all is well there with you and yours my friend. May see you at the mow-in.
 

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Discussion Starter #918
Al, Sorry to here about your inop PTO. Yes hope to see you at the mow-in, lots going on here, I hope I can get away.

Here are some shots I took while mowing at the new house today.



The new trailer.









Dual blades make neat and fast work of even tall grass.

More later,

Sheldon
 

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A green as that grass is in August and as much rain as we have had, you must not be too far from 21050.
 
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