OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Tech Talk GV150 tuneup help needed

I've downloaded the file and soon as I have the parts I will read the file again very carefully . Iwill let you know how I go . I very much appreciate all you have done and will follow your instructions .ps who said you are grumpy? Take care.

roebuck, part of the reason I want you to read that oil seal installation paper carefully, is that we still need an explanation for why your two previous seal installations leaked badly. I'm concerned that you may have put the seals in backwards. Here is the lubricant flow diagram from the workshop manual:


In what seems a rather bold design decision, Honda has elected to direct the full output from a Hobourn-Eaton (trochoidal) oil pump up through the hollow camshaft, into the space between the ballrace and the top oil seal, under pressure. From there it trickles and splashes down to lubricate the remainder of the engine. This means the top seal is actually under pressure from inside the crankcase. It can only restrain the oil from actually pumping out of the top of the engine in quantity, if the oil seal is pressure-tight.

Here is a typical double-lip, spring-loaded oil seal, which may be similar to the one Honda uses:



The red oval shows the "dirt lip" side of the seal. This side must be on the outside, not the pressure side, of the seal. Its only function is to keep crud from getting close to the "real" lip and wearing it out. If pressure is applied to the dirt lip side of the seal, it will simply lift the real lip out of contact with the shaft.

The green arrow shows the side of the seal that must face toward the source of oil, and pressure. The more pressure is applied, the more tightly the seal will seal. This pressure side of the seal must face toward the ballrace.

This is the way I would have pressed it in . The next picture I wouldn't of pressed it in.
More pics of the bearing housing and oil passage . Hope that's what you mean.
Another picture of the seal the right way up on the shaft . The seal you see is from another engine so ignore the size only for demo.
Is this what asking. Cheers.

The open side of the oil seal must face toward the ballrace. The closed side should face upward, toward the breaker points. As far as I can tell, that is the way you have shown it in the pictures, so we still don't have an explanation of why it leaked.

Hi Grumpy,I've received the new seals for hond gv 150 . The one from USA are redish they where bought by engine number . The black seal I bought from local honda shop as a replacement. The redish one is slightly higher on the outside wall.
The redish ones are left and right the black is middle ,does this make much difference. The bearing arrived as well and it was ordered the same way from USA by engine number as a replacement . It appears to be slightly thinner around the ball race which may take a bit of pressure off the seal maybe.
What do you think

First, in this application the thickness of the seal probably has no effect, as long as the position of the sealing lip is the same distance from the engine side of the seal (not the breaker points side). If that distance is not the same, the sealing lip may not run in the old position (the worn, polished circle around the shaft), which is not important anyway as long as the shaft is smooth, and the polished circle is not worn down to a smaller diameter. (Since the shaft is less than the seal's nominal diameter of 25 mm anyway, you would not want to make the situation worse by running the lip on a worn-down spot on the shaft.)

The picture of the ball races does not show the brand of the new one. Because it is marked 6205/P6, I think it is probably SKF brand, because P6 is a specific SKF tolerance class. The old bearing was NTN brand. They are both reputable brands, and they are both 6205 open bearings. The minor variations in features between manufacturers are not something to be concerned about. The important thing is whether the old one has any more slack in it than the new one. If you can reduce the slack (amount the outer ring can move radially or axially when you hold the inner ring in a fixed position) by replacing the bearing, that will make life easier for the oil seal.

The first important test is whether the main lip of the oil seal contacts the shaft securely all the way around it. The second important test is whether it does so when shaft, bearing and seal are all installed in the engine. Aside from that, and making sure the seal is installed the correct way around, without any trauma to the seal's lip during assembly, it should work. Note that it is desirable to lubricate the seal lip before you push the shaft through it.

Please post some pictures as you go along with the assembly process. I still don't have any clue as to why the seals leaked on your previous tries at assembling the engine. There is still some mystery here, and it has the capacity to bite us on the backside.

Ok thanks heaps Grumpy, will keep you posted with pics.

I'm going to press seal 2mm . There are no grooves in the shaft that I could find with my fingernail. Not forgetting to grease oil seal lips first. Hope this is right.

If this fails I will move the seal even higher up the shaft. This is at least 2 mm higher than where I normaly would have pressed it in plus it was very tight fit . A lot harder to press in this seal from the others previously. There was no play in the crankshaft where as before with the old bearing there was a very tiny bit of play and I mean very little . Will let you know how it ends up.

That looks like the dirt-excluding lip on this side, which would make it the right way around. The "real" sealing lip is always a smaller diameter than the dirt lip, so it looks right so far.

This is the beast Honda all together . I will take the GV for a mow tmrw if it will start. After a run I'll take the top off and inspect the seal.


Thanks grumpy . I will get back to you after test.

If there's any doubt about it starting, roebuck, it sounds as if there is more work to do after the oil seal is sorted out. A side-valve Honda should start within two pulls, even if it has been standing for quite a while. (An OHV Honda should start first pull.) Anyway, let's get to the bottom of the oil seal issue first.

You posted a picture of a used oil seal laying on part of your engine. I doubt it is one of the an actual seals you had fitted to that engine, but we can use it to discuss one possible explanation of why your seals have been leaking. Here is the picture:


That seal seems to have had some spectacularly bad experiences. The red oval shows mangling of the garter spring, and heavy damage to the main seal lip. The yellow oval shows the imprint where the garter spring has been stretched out of position and pressed very hard against the web of the rubber part of the seal. All that probably happened when the seal was extracted from whatever engine it was in. However it illustrates what can happen under some circumstances, if you press a seal way too deeply into the bore it mounts in, so the inner ring of the ball race contacts the rubber part of the seal and then deforms it, so its sealing lip is not in contact with the shaft.

That malfunction is only possible in cases where two conditions apply. Firstly, the seal must be open on the oil side, like your GV150 seals, instead of having a double steel housing, like the one I showed in section in the diagram with the green arrow. Secondly, the seal has to be pressed into a smaller bore than the ball race.

Often an oil seal is in the same bore as the ball race. There is then not much of a problem with even an open-sided seal being pressed in too far, because the steel housing of the seal will hit the outer ring of the ball race, limiting how far you can press it in and preventing lip contact with the inner ring of the ball race. However when the bore the oil seal is pressed into is smaller, an open-sided seal can be pressed in considerably further, because its steel housing will miss the outer ring of the ball race and continue moving until the steel housing hits the ball cage. By the time the housing hits the ball cage, the inner ring of the ball race may be forced a long way into the rubber part of the seal, perhaps deforming and expanding the sealing lip.

In summary, the above is one possible explanation of what went wrong with your seal installations. If that is what happened, it seems to have been caused by the wrong instructions you got from the counter jockey at your Honda dealer, when he told you to press it in to 5 mm below flush. As you know, Honda specifies 2 mm below flush, and this may have been for a very good reason.

Hi Grumpy , I've done approximately 2 hours of mowing and running the engine varying the throttle but mostly at about the 3/4 rev range and didn't miss a beat . Usually I would of only run for 10 minutes when it would flood the points then stall . I've taken the lid off and checked it for no oil ,all is good put the lid back on and started it first pull . The seal you pointed out was from a b&s and the damage was caused from extracting it. I think you hit the nail on the head and by moving the seal slightly it has cured this problem. When the diagram stated the oil seal should be 2 mm below the top ,this is what stuck in my head . I would not of fixed this problem without your instructions as I would have kept on pressing the seal in too far . I'm very grateful for your patience and knowledge and I now have a lot more of an idea on how a oil seal actually works. I love this mower and can't thank you enough for all of your advice . Fantastic forum.

Thank you for reporting back, roebuck. A detective story without a solution frustrates everyone who reads it, so your final post is the most important one in the thread.

I'll close this thread. You are welcome, of course, to start another one at any time if you have an issue for discussion. Also, if anyone needs to post to this closed thread, just send a PM to a moderator.