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Post by elsiefan on Apr 13, 2023 14:42:33 GMT 1
Hello all, I put what I thought was 1.5L of oil in the gearbox, but my dipstick showed I had overfilled it. Even after running the engine for a while, going up and down the gears, the level was still high. I had the dipstick resting on the case, not screwed in. As with so many things on my LC I am not sure if this is the correct item for my bike, so I measured it and the length to the flat tip was approx 100mm and 110mm to the end. Is this correct for an '81 4L0?  IMG20230413121506  IMG20230413121622 |
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Post by Chewie01 on Apr 13, 2023 14:54:41 GMT 1
I had a same thing happen when I last changed the oil in my F2.
I removed the extra oil but every time I checked the level it was too low. I ended up putting all the oil I have taken out back in, ending up back with the same amount of oil I started with.
I assume it must not have distrusted through the engine fully.
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Post by elsiefan on Apr 13, 2023 15:34:56 GMT 1
That is a possibility, I only ran the bike for 10 minutes or so, which may not have been enough.
Though I did leave it overnight and got the same reading the next day.
I know I have a 'bitsa' so it would be good to know that my dipstick is the correct length and not designed for another make / model of bike.
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Post by mouse on Apr 13, 2023 16:59:53 GMT 1
Here you are, measured from under the top, about 106mm 
HTH
Mouse |
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crigar
Weekend rider
Posts: 89
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Post by crigar on Apr 13, 2023 17:05:04 GMT 1
My experience has shown that you can't rely on the gauge, the important thing is the quantity. After an oil change without dismantling, you should put 1.7 liters without risk because the breather prevents overpressure.
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Post by arrow on Apr 13, 2023 17:21:36 GMT 1
I used to run with 2 litres of gearbox oil in my 4LO. Makes the clutch much quieter.
No problems with doing that.
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Post by 4l04ever on Apr 14, 2023 0:16:16 GMT 1
I fill to the marks on the dip stick, which always ends up less then 1500ml.
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Post by elsiefan on Apr 14, 2023 0:35:36 GMT 1
Cheers for the help guys, looks like it is a 4L0 dipstick, which is nice to know.
I'll leave the 1.5L I poured in and see if it settles in time.
Interesting comments on running more oil than std.
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crigar
Weekend rider
Posts: 89
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Post by crigar on Apr 14, 2023 9:15:28 GMT 1
For me gearbox oil 75w80 or 75w90 max GL4 (otherwise too many anti friction additives), also Motul Transoil
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Post by chrisg on Apr 14, 2023 11:26:32 GMT 1
I suspect the 1.5l reffers to a bone dry factory engine. The clutch sucks up some of that and some oil sticks to all the gears, cases etc.. so you there is always residual oil left after draining.
I always go of the dipstick, but do monitor the amount going in.
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Post by 4l04ever on Jun 1, 2023 10:56:19 GMT 1
As a follow up to this, one of my friends has just had his 6th gear overheat and the selector fork died after riding steady in 6th for a long ride. Looks like the oil level needs to be high enough to get in the selector fork grooves with the bike running. The approximate diameter of the selector fork groove is 35mm, so oil level would need to be around 15mm below the centre line of the engine casings to get to coating the surface of the groove.
I will measure how much oil it takes to get to that level in a 4L0 engine and will see where that is on the dipstick.
6th gears sit the highest as they are both medium sized rather than one large and one small, where the large gear would drag up oil and around.
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crigar
Weekend rider
Posts: 89
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Post by crigar on Jun 1, 2023 14:23:35 GMT 1
6th gear wear is a known problem: gearbox oil level too low.
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Post by 4l04ever on Jun 20, 2023 9:03:55 GMT 1
Following on from this, I was checking the Yamaha Service Manual as to how they say the transmission oil should be checked.
This is what it says :-
2. Transmission
a. To check level, start the engine and let it run for several minutes to warm and distribute oil.
With the engine stopped unscrew the dipstick and clean. Set it on the case threads in a level position.
Remove and check level.
NOTE:
Be Sure the machine is level and on both wheels.
b. The stick has Minimum and Maximum marks. The oil level should be between the two. Top off as required.
Transmission oil quantity:
Total: 1,700cm3 (1.496 IMP. qt)
Exchange: 1,500cm3 (1.32 IMP. qt)
From the above it looks like you should start at 1.7L on a new engine build not 1.5L.
Also, since it says to run the engine and get it warm and to distribute the oil then check the engine, it does not say to let the oil settle. That would negate the work done by running the engine and the oil would not be distributed like when the engine is running.
I checked the oil straight after stopping the engine and found that there was no oil on the dipstick with 1.5L, 1.7L, 1.9L or 2.1L. I went up to 2.3L and then had oil on the stick!
Luckily, the engine I was working on had a clutch window so I could see the oil level inside the engine. Even though 2.3L sounds a lot
it was still about 17mm below the centre of the clutch when left to settle, but as soon as the engine started, the oil level dropped to below the window.
The diameter of the selector fork grooves is about 35mm, so radius would be 17.5mm. This would mean my 2.3L of oil is close to touching the selector fork grooves when the engine is stopped, and is also touching the 58mm OD 6th output gear.
I am going to try running 2.3L for a while and see if there are any issues, but so far so good!
On another note, I have seen quite a few LC/YPVS bikes with clutch windows and their oil level varies significantly when stopped, from below the window to half way up the window.
I think a lot of people have only put 1.5L in on new engine builds, which needs to be 1.7L according to the Yamaha book.
What are you views on how quick to check the oil after stopping the engine, as if it was meant to be left to settle, I am sure it would say to leave for so long before checking rather than saying to run the engine prior to checking the oil???
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Post by 4l04ever on Jun 20, 2023 9:16:06 GMT 1
Example bike with no oil showing in window.  ...and another  Some oil visible in this banshee...  No oil visible on this one...  Oil level similar to my experiment on Chris's brothers bike.  |
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Post by Tobyjugs on Jun 20, 2023 9:33:20 GMT 1
Speaking from experience, if lots of people just fill the the oil to the dipstick that's the first mistake. The oil will stay on that side of the engine casing for a while.
Once you start the engine up it will rapidly drop showing a low oil level again.
The original sump plug blocks two different oil passages in the bottom of the block. This keeps both sides of the oil areas seperated. I keep to the same plugs on my road bikes.
Some people like to put in short plugs.
If the static oil level is correct there will be plenty of oil thrown around the engine to lubricate the selector forks. I would look to the correct tolerances between the gear clusters or check the selector forks condition.
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Post by rigga on Jun 20, 2023 11:25:40 GMT 1
Here's my level on the side stand. Slightly higher when the bikes upright. Not had any issues and an easy level check against the bolts.  |
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Post by midlifecrisisrd on Jun 20, 2023 16:06:41 GMT 1
Speaking from experience, if lots of people just fill the the oil to the dipstick that's the first mistake. The oil will stay on that side of the engine casing for a while. Once you start the engine up it will rapidly drop showing a low oil level again. The original sump plug blocks two different oil passages in the bottom of the block. This keeps both sides of the oil areas seperated. I keep to the same plugs on my road bikes. Some people like to put in short plugs. If the static oil level is correct there will be plenty of oil thrown around the engine to lubricate the selector forks. I would look to the correct tolerances between the gear clusters or check the selector forks condition. Totally agree On a new build or change I park it on a paddock stand and add about 1.4l Leave for half an hour and keep going back and topping up till it has the correct level after sitting And I always use the long drain bolt If not it doesn't take a genius to work out what happens to the oil level in the gear cluster section on a long right hander 🧐 Steve |
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Post by midlifecrisisrd on Jun 20, 2023 16:08:04 GMT 1
Good info Rob 👍
It's the ones that think you have to screw the dipstick in to check the level too 😬
Steve
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Post by elsiefan on Jun 21, 2023 0:21:42 GMT 1
Agreed, good work Rob.
On the back of your comments, I added another 250cc to the 1.5L I put in after the rebuild, then after a great 150 mile thrash last weekend, checked the level again and it was just at the top of the hatched area on the dipstick, which was a little above where it was after the 1.5L I put in finally settled to.
Can someone please explain about the different drain bolts people mentioned above? and how you can tell which one you have?
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Post by midlifecrisisrd on Jun 21, 2023 8:25:24 GMT 1
Agreed, good work Rob. On the back of your comments, I added another 250cc to the 1.5L I put in after the rebuild, then after a great 150 mile thrash last weekend, checked the level again and it was just at the top of the hatched area on the dipstick, which was a little above where it was after the 1.5L I put in finally settled to. Can someone please explain about the different drain bolts people mentioned above? and how you can tell which one you have? Original drain bolt is a good 20mm + long so that when it is fitted it blocks off the clutch case drain hole Aftermarket and magnetic ones are only about 12-15mm long so leave the drain hole from clutch case to gear cluster area open while allows oil to move between these areas quickly so oil level varies as the bike is leaning over cornering Steve |
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Post by Tobyjugs on Jun 21, 2023 9:25:15 GMT 1
If the oil level is too high I think it will just spew the extra oil out the breather pipe.
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Post by midlifecrisisrd on Jun 21, 2023 10:58:14 GMT 1
If the oil level is too high I think it will just spew the extra oil out the breather pipe. It certainly will Had a lucky escape back in the day when the oil pump seal failed and filled the gearbox with 2 stroke oil Pissed all over the back tyre as the vent tube wasn't routed to the front sprocket case as it should be Steve |
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Post by headcoats on Jun 21, 2023 12:41:16 GMT 1
So is the long (standard) bolt sump plug and 1.7 litres of oil the way to go
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Post by 4l04ever on Jul 28, 2023 9:03:08 GMT 1
If the oil level is too high I think it will just spew the extra oil out the breather pipe. At 2.3L of oil, after a few hundred miles, there has not been any oil come out the breather. :-) Perhaps a crank seal or casing seal leak could pressurise the gearbox area, which would then push the oil out when the engine runs. |
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Post by Tobyjugs on Jul 28, 2023 10:31:20 GMT 1
If the oil level is too high I think it will just spew the extra oil out the breather pipe. At 2.3L of oil, after a few hundred miles, there has not been any oil come out the breather. :-) Perhaps a crank seal or casing seal leak could pressurise the gearbox area, which would then push the oil out when the engine runs. No i just mean when the oil level is too high (what ever that is) it will spew oil out the breather pipe. |
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Post by JonW on Jul 30, 2023 1:54:14 GMT 1
At 2.3L of oil, after a few hundred miles, there has not been any oil come out the breather. :-) Perhaps a crank seal or casing seal leak could pressurise the gearbox area, which would then push the oil out when the engine runs. No i just mean when the oil level is too high (what ever that is) it will spew oil out the breather pipe. Its when youre on the back wheel... lol... maybe... logically, all the oil runs to the back and if youve overfilled it and wheelie for a long time it'll defo come out the breather I think this is a great thread, Ive noticed the different length sump bolts but had no idea how they worked. Good stuff! |
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