OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Honda Engines GXV140

Hello

I have Honda HRB215 SXA lawnmower with GXV140 engine. The motor starts and runs perfectly. However the engine is dripping oil below (about 1 drop per second). Honda dealer said the oil seal at top end of crankshaft was probably pushed from excessive pressure (if the engine had too much oil).

I removed the blades and did not notice any oil leaking from the oil seal at the bottom of the crankshaft. However I noticed oil dripping from inside bottom edge of cylinder. Looking at the parts list diagram online I notice that there is a cylinder head gasket that could be leaking. However if there is a leak here I imagine that engine should not run that smoothly.

It's possible that I flooded the engine with oil (it's so hard to read the oil gage with my old eyes). How can can I tell whether the oil is leaking from the top crankshaft oil seal or from the cylinder head? Also, I could not find anything on the internet on how to replace the cyclinder head gasket for this engine or how to get access to the top oil seal. Appreciate any suggestions

Thanks

Hi kurb, welcome to Outdoorking.

The first step is to check the oil level. The GXV140 has a one-piece plastic dipstick with cross-hatching in the area where you have to read it, so it should not be too difficult. Remember, Honda dipsticks are read after inserting the dipstick but leaving it unscrewed from the crankcase and just resting against the top of the thread. This is opposite to Briggs & Stratton dipsticks, which like car dipsticks are read after fully inserting and seating the dipstick.

To be able to read the stick, you need to place the mower on level ground, then unscrew and remove it, and wipe the end of it clean and dry. Then place the stick back in the hole without screwing it in, and immediately lift it out again. Keep it vertical so oil will not run up the stick and make you think the level is higher than it is. Use a flashlight if necessary to inspect the position the oil has reached on the stick. It should be right at the top of the cross-hatching. If the stick is wet with oil above the cross-hatching, it is over-filled with oil, and this must be corrected as the first step.

If the oil leak continues when you are certain the oil level is correct, there are several possible causes. In addition to the two your repairer suggested (top oil seal blown out, or leaky head gasket) there are two others: leaky valve cover gasket, or stuck Positive Crankcase Ventilation valve. We can work through all of them, but other than the gasket leaks, they involve partly dismantling the engine. The blown seal or stuck PCV valve both require use of a 6" gear puller to remove the flywheel.

Please check the oil level carefully, and report what you find - then we can move forward a step at a time. In my opinion it is better to do this by investigating the cause before attempting the cure. Also, where the oil is coming from is not necessarily the key issue: if it is overfilled with oil, or the PCV valve is stuck, oil is likely to come out somewhere, regardless of the quality of the gaskets.

Hi grumpy Thanks.

Thanks for the reply. The oil is leaking with correct oil level. The oil overflow happened before , and I suspect that that may have started the leak which I am only now noticing.

I would like to eliminate that this is not a cylinder head gasket proplem. I can see oil dripping from the inside right end (the last fin) of the cylinder head. The gasket is before that. The engine is running smoothly.

I think that I can get a free loan of the 6" inch puller from our local automotive store. I am assuming that I will be able to see the top oil seal once I remove the flywheel. I am wondering that on replacing the flywheel whether it has to be aligned to some mark for the correct firing of the spark plugs.

Do I have to get a service manual to get this right? Thanks

Well, we are getting further ahead. Can you post some pictures of the leak please?

If it is a cylinder head gasket leak, it may be either because the seal around the combustion chamber has blown, or because the oil passage to the valve gear is leaking. It is important to know which, and pictures may tell us, particularly if you clean the area, then make it leak and photograph it immediately.

I customarily address these problems in the Sherlock Holmes manner, by tracing cause to effect. If the cause were over-filling with oil, I do not think it all that likely that the result would be a blown-out top crankshaft seal: in my experience those seals are not all that easily pushed out, while some of the engine gaskets are relatively easily blown. I have seen this problem before, though on a copy of a Honda not a real one (the copies are called "chondas" here in honour of their country of origin) and the symptoms so far are reasonably similar - however oil came out through a multitude of gaskets on that engine, not from under the engine's red plastic top cover, as it would if the top crankshaft seal were leaking. My first guess would be that the excess oil that was in your Honda has caused oil to flood through the PCV valve into the oil-separating compartment under the flywheel, and (probably temporarily) caused the valve to stop working, thus pressurising the crankcase and forcing oil out from the point of least resistance. If it couldn't go through the PCV valve, it had to blow a gasket or a seal. In that other case, the oil began by coming out past the gasket around the cylinder head's valve gear oil passage (underneath the head, not on top of it), but as the mower kept being run, it started coming out from the crankcase cover and the bottom oil seal as well. You can help resolve this possibility with your engine, by pulling off the rubber breather hose from the bottom of the air cleaner box and seeing if there is oil in the hose. If there is, it is consistent with my guess, though it does not confirm it. Incidentally, please do not run the engine for long, since if it is generating pressure in the crankcase, it may blow a gasket rather than cause one to leak temporarily. This is more difficult to fix.

Hi grumpy

I am glad you encouraged me to do some detective work.

I cleaned the area and then ran the engine for about two minutes.
The leak is coming from the oik pan gasket in the same are where I though I had seen the it dripping from the cylinder head. The cylinder was dry, no leaks there. I then cleaned the area and ran the engine for just 10 seconds or so and confirmed the source of the leak. Its possible that I might see another leak if I ran the machine longer. Here's a pic



https://www.dropbox.com/s/ozssx8it90my8wc/GXV140Leak1.tiff

OK, now what? Tighten bolts? Replace gasket? It seems gasket is discontinued for some reason. Anyway, does this mean I have to get the engine off the frame. I see five nuts at the bottom. I guess I have to remove blades and clutch and any cable. Any guidelines on how to remove clutch??

kurb

Unless the engine has been dismantled at some time, it is unusual for a Honda to leak oil through a gasket. I suggest your next step should be to read through these two threads:

https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=49392&page=2

https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=52741#Post52741

At the moment I'm having some difficulty finding the joint face, where the gasket is, in your picture (though I see the oil of course). Is it the gasket inside the green oval in this picture?


(That picture is of a GXV120 not a GXV140, but the crankcase cover is the same part, and the cylinder/crankcase is the same except for the bore diameter.)

If it is the crankcase cover gasket that is leaking, we still have the question of why. Did you check for oil in the rubber breather hose? If the problem is a stuck PCV valve, you cannot cure it by increasing the clamping force on a gasket: all that would do is cause it to leak through another gasket. On the other hand if the engine just has a loose crankcase cover, and the previous over-filling with oil had nothing to do with the problem, tightening the cover bolts would probably be a complete cure.

By the way, I notice you do not have a workshop manual for that engine. Here is a free download of the "short-form" version of the manual:
http://www.honda-engines-eu.com/documents/10912/31969/1551/b10d7687-f6e2-40e0-9faa-ef36e383cc9b

Hi grumpy

Thanks for all the info.

Yes it's the gasket in the green oval in your. Here's another view of the same leak



[img]https://www.dropbox.com/s/5ukfhhu367zxxjd/GXV140Leak3.tiff[/img]

Its dry above the gasket line, wet below. I don't see anything anywhere else so the oil in the pic is from the oil pan gasket. And the rubber breather hose is clean. See pic



[img]https://www.dropbox.com/s/c6a749hj00pkbg1/GXV140Leak4.tiff[/img]


Last year the machine seized (ran out of oil after 23 years). I managed to unseize it by adding magic oil and then every day for a week worked on the flywheel to it it rotate freely. I then ran the engine with fresh oil and then flushed the oil again. Its possible that I had too much oil when I did it. This could have damaged something.

So for now I need to fix the oil pan leak. I should tighten the cover bolts as you suggest. How many are there and how do I access them? Something like


Drain gas, drain oil
Remove blade
Remove clutch (I tried turning the nut, but it turns freely)
Remove plastic cover protecting transmission?
Remove belt - how to release tension
Er, do I really need to remove clutch first to remove the belt
Undo bolts holding engine to chsssis (I see five nuts)
Lift engine

I wonder if that makes sense

Thanaks for your help!
Kurb
Undo nuts holding

The crankcase is secured by 7 bolts, circled in red in the above picture. They should be torqued to 9 lb ft (12 Newton-metres). Torque them all to just 3 lb ft first, working diagonally, then increase to 9 lb ft, then run around them circumferentially to ensure you haven't missed one. Pay attention to whether any of them is substantially looser than that, and report back please.

On the Honda mowers I'm used to (bear in mind that the Australian versions mostly have no clutch or brake) the engine is held to the mower base by 4 bolts, which go into tapped holes in the crankcase cover. I haven't seen one with belt drive to the transmission, but it sounds easier to deal with than the propellor shaft coming out of the crankcase cover that I am used to.

Hi grumpy

Thanks for the info and the pic
I finally got he engine out. See pic



[img]https://www.dropbox.com/s/r39qtxow3ik8kl5/GXV140Leak6.tiff[/img]

So one of the bolts(near) the leak was looser than the others, so I think that this is the culprit. Since it was such a bigger to get the whole thing I am wondering whether it makes sense to replace the gasket. Actually, they don't make these gaskets any longer. Honda dealer told me to use product called "Honda Bond". It's a silicon based glue, costs about $10US per tube. Not sure that its worth the extra effort/risk.

I am thinking that while I have the engine out I should test for the leak. Put some thin oil in and blow through the filler hole (if necessary) to precipitate the leak. Then tighten the nuts and see if that fixed the problem.

It was quite a bugger to remove the two nuts that holds metal base plate to the oil pan, even with an impact wrench. Do you know what the torque for these two nuts should be? I have to find me a torque wrench somewhere for both these nuts and the oil pan. Honda dealer said that the torque for the 7 nuts was 7.8 lbs. Thanks, kurb

Here is the page from the on-line Honda GXV140 service manual, showing specified torques for the most important bolts:



I think your dealer looked up Honda's standard torque for a 6 mm bolt (7 lb ft unless otherwise specified), rather than looking up the actual bolt.

I don't know where the rumour that the crankcase cover gasket is unavailable, came from. The part number is 11381-ZG9-T00. Here is a US dealer listing for it:
http://www.2lcstore.com/catalog/item/4771015/4843300.htm

The crankcase cover, and the gasket, are the same as for the Honda GXV120 engine, which is still in production, so it would be unlikely that the gasket would be discontinued. I suspect whoever told you the part was not available was looking it up in the wrong way. The GXV140 engine went out of production in 2003, so some of the parts listings for it may be getting a bit erratic by now, but the majority of the parts are the same as GXV120 ones.

Never substitute sealant for a gasket on a small engine's crankcase cover. On Honda and Briggs engines in particular, the thickness of that gasket controls the end-float (i.e., axial slack) of the crankshaft. The sealant has a compressed thickness of almost zero, versus about 1 mm for the gasket, so you would be reducing the end float by 1 mm. I don't know of a specification for the end float of the GXV140 engine, but for the GCV160 it is 0.1 mm to 1.0 mm. Unless your engine is fairly worn, it might have negative end float without the gasket, which would cause it to lock up and refuse to rotate when you tightened up the 7 crankcase bolts. Some engines (in particular, Honda's OHC mower engines, which are for "residential use", compared with the OHV engines like yours being for "commercial use") originally use sealant instead of gaskets, and of course the crankshaft end float is designed accordingly. You should always use the parts specified in the original design, unless you are planning to experiment with a modified engine design for some reason.

When a gasket has leaked, it is good practice to replace it. In this case, when you have the engine out of the mower and can replace the gasket with very little work, it would be best to do so. However if your local dealer can't supply the part, it may take you a week or two to get one from the US (Canadian customs delays are somewhat notorious, though Australian ones are much the same) and I suggest you don't remove the crankcase cover until you have the gasket in hand. Gaskets fairly often break when the parts are dismantled. Remember when you talk to your Honda agent, the gasket is the same part as the GXV120 one. If he cannot supply GXV120 parts (possibly Honda's most popular engine, ever since it was introduced in 1983), I suggest you choose a different agent in future. Frankly, he doesn't seem to have covered himself in glory with this repair process.

Hi grumpy

Thanks again, boy you really know your stuff.

When I checked online ( http://www.ereplacementparts.com/ho...ine-parts-c-37657_37658_38012_64902.html ) it said that that part number for the gasket was obsolete and Honda dealer told me to use the silicon stuff. I'll try to get the gasket, and try to use the GXV120 approach. It will take more than a week to get from the States unless I use courier.

The torque that I needed to know for the base plate are the two bolts you can see in my pic. The base plate connects to the chassis via 3 bolts and to the engine via the two bolts. I didn't see them referenced online manual.


Thanks again, Kurb

The on-line manual is just for the GXV140 engine, not the mower frame. I do not have a manual for your mower, but the usual process is to use specified values where they feature in the manual, and default values elsewhere. I have looked in the HR214 manual and no torque is specified for the engine attaching bolts. Here are Honda's torque values for that mower, including the default values, for each size of bolt:



I suggest you measure the diameter of the bolts, and look up in the above table, the default torque value for that size of bolt. It will most likely apply, and should do no harm. You will find that in general, when the bolt is screwed into aluminium with a thread length exceeding twice the diameter of the bolt, the specified torque is higher than the default value.

Thanks mate!!

If I unloosen the oil pan nuts will the oil just lift off, or do I have to take oil seal out first? I think this requires a special tool, also should I replace the seal while I am at it?

kurb

Don't interfere with the oil seal, kurb. The crankcase cover will slide over the crankshaft - just make sure you've removed the key from the keyway first, or you'll destroy the seal. It's a Woodruff key (half-circle) so it may take a minute or so to get it out of the crankshaft.

However the crankcase cover is held in place by a pair of dowels as well as the 7 bolts. Just tap the other side of the cover lightly with a rubber hammer, one tap on each of two opposite points on the cover, then repeat. Be gentle, it will probably take half a dozen taps on each side. Once it's off the dowels, it just lifts off. But remember to remove the key!

OK grumpy I I think I have already removed that key, unless there are two of them. See pic. This is after I removed the clutch. There are two washers (shown in red) and the blue arrow is I think what you call the Woodruff key. It came out quite easily actually



[img]https://www.dropbox.com/s/nvmeculz63xdd0u/GVX140Leak7.tiff[/img]

I just want to clarify what you mean about removing the oil pan. So if I look at the photograph you want me to tap on the underside (ie tap upwards) at the edge of the oil pan cover and repeat at diagonally opposite end on the underside. And I can select any point on the circumference to do this

Another question if I may. This is a pic of the clutch .. The circular spring fell when I removed. The photograph shows the way to insert the spring (yes?) and the tabs on the spring on the does not have to align to anything (yes?)



[img]https://www.dropbox.com/s/i2ntr841oxcqzf4/GVX140Leak8.tiff[/img]

If I have not already thanked grumpy then:THANKS AGAIN!

Yes, that is the Woodruff key, at the tip of the blue arrow. If you got it out easily, you were fairly lucky - sometimes it is difficult to get them out.

So long as the two points on the crankcase cover (sump) where you tap are directly opposite each other, it is not important where they are. I select them according to where the cover extends well beyond the crankcase itself, so I have room for the rubber hammer. Remember, just one light tap, then go to the other side, so the cover comes off in tiny increments without tilting relative to the crankcase. If it tilts, the holes the dowels are in will become deformed. Do not put a screwdriver or anything else between the crankcase and the cover, or you will damage the surfaces and cause an oil leak.

The clutch spring, which is of a type called a Belleville washer, is there to push the two halves of the dog clutch apart until the central spline disengages. You should be able to see marks where the tabs have been sliding around one half of the clutch, and marks where its outermost region has been pressing against the other clutch-half. I can't see it perfectly in the picture, but it looks as if I'm seeing rub marks under the tabs, and rust marks on the outer region of the other part. If that is correct, you have it in the right way up.

The tabs can't align with anything rotationally: whenever the clutch is disengaged, they are spinning relative to the clutch-half they are resting on in your picture.

Thanks grump

I got the gasket for the oil pan (returned the Honda Bond to the dealer). I'm glad that i decided to change the gasket rather than tighten the bolts. The gasket was broken where the leak appeared. See pic



[img]https://www.dropbox.com/s/ulgtu41xca807pt/GXV140Leak10.tiff[/img]

I am now have some trouble inserting the pulley into the crankshaft. The Woodruffe key tends to revolve (back end moves up) and prevents pulley from going fully in. I tried oiling it but it didnt help. Is there a trick to doing this?

kurb

Thanks kurb. Of course you are right, there is no way tightening the bolts would have stopped that leak. However, something has to have caused the damage to that gasket. I can't recall seeing a gasket damaged in that way except by it adhering to a bolt when the bolt was removed, so the damage may have occurred when you dismantled it. Nevertheless, when you open the crankcase in a case like that, it is good practice to push a 1/16" drill bit through the PCV oil return passage, circled in green below:


Just hold the drill bit in your fingers, and do not rotate it, or it will catch in the mesh that separates the liquid oil from the droplets, inside the PCV compartment.

The problem you are having putting the hub back over the Woodruff key, is the converse of the good luck you had when you took it apart, in finding that the key was not tight in the keyway. I suggest you take the key out of the keyway in the shaft, and try to slide the top of it into the keyway in the hub, starting at the end of the hub that goes onto the crankshaft first. If it won't push in under firm finger pressure, you need to look closely for a burr or dirt in the keyway, or some minor damage to the top of the key. Also check that the keyway in the shaft is clean, and the key will fit into it right to the bottom.

Remember, the key has to finish up being a good fit in both halves of the keyway (both crankshaft and hub), or it will knock annoyingly, and soon wear out. Do not file down the key, but if you find a nick or burr, you can smooth it across with sandpaper.

Thanks grump

I'll try your suggestion regarding the Woodruffe key. Earlier I tried putting it in the hub wrong way round and miraculously it went in, but ofcourse that's no use

Question: What's the purpose of pushing though the drill into the PCV oil return passage, or rather what's the risk of not doing it? For some reason I am somewhat reluctant to take the engine out and undo the oil pan. Also, I am not exactly sure about the procedure. Hold the bit in your hand, push it through the hole to some depth and than remove it? When to stop pushing?

Thanks, Kurb

Hi Kurb, I certainly don't recommend taking the engine out again to clear the PCV oil return - it is just something that in my opinion should be done whenever you have an engine open and have the slightest suspicion about the ventilation system. The process I use is to hold the drill bit in my fingers and push it in about 5/8", then pull it straight back. You usually feel some resistance as it reaches the far end of the drilled hole, then it breaks through and you feel a springiness as the drill bit presses against the woven mat. You pull it straight back without rotating it, or the drilling flutes will entangle in the mat, and you'll then have to rotate it anticlockwise a bit to get it out. It is just a ritual I tend to go through, to ensure that something is not wrong. If I wanted to do it once the engine is reassembled and back in the frame, I'd do it from the top, not the bottom. You can remove the top cover/fuel tank, the starter, the flywheel, the top cover of the PCV compartment, and the oil separating mat. The top end of the drain hole is then accessible from above. However I don't propose that you do this, since there is not enough evidence of a problem.

I'm not entirely convinced that your PCV drain is clear, I just don't see it as an issue since your breather hose had no oil in it. To give you an idea of how well the system drains when it is working properly, though, here is something that happened to me 3 months ago with a GXV120 engine I'd just put new rings in, and reinstalled on my favourite mower (a 1980s HR194). I parked the mower near the edge of a slightly raised concrete area while I emptied the grass catcher, leaving it idling as I always do, and heard a crash from that direction while I was emptying the catcher. I looked around, and saw the mower exactly upside down, having fallen off the raised area (must have rolled a few inches I guess). It was still running perfectly. I walked over to it, put it back on its wheels, and went back to my catcher emptying. It continued to run perfectly except that it smoked heavily for about 15 seconds or so. By then I'd finished my chore and resumed mowing, with no remaining symptoms from the adventure. Essentially, the PCV compartment filled with oil while the mower was upside down, and when I righted it, some of that oil went into the breather tube while the rest of it went through the oil drain passage back into the crankcase. Gas flow through the breather tube took the oil with it, through the interior of the air cleaner, carburetor and intake pipe, into the combustion chamber where it was burned up with no harm done.