Can I resurrect this one?  The link above to the seal no longer works.  Where is the seal and how much stripping down is needed to get at it?  I couldn't see anything obvious in the manual.

 

Three trials after the first oil change I have done on the bike the level is down to the minimum.  There's no obvious burning of oil.  I have not yet had the chance to drain the gearbox to see if that is where it is going but the breather hose is clear to atmosphere so it should not be over pressurised to end up there.

 

All advice gratefully received.

which seal are you meaning?

The bike can throw oil out of the breather if its been upside down.

Never heard of it ending up in the gear box.

Any signs of oil on the sump guard?

Maybe top up a little and keep an eye on it.

Edited January 5, 201610 yr by jrsunt

Did you do the oil change yourself? Did you let the engine run for 3 min. and then rest for 3 min. after the oil change to check the oil level? (I know this should be obvious but you never know 

 

If engine oil somehow gets in the gearbox, which would surprise me, I suspect it's via seal n° 31 (sits between the crank case and the primary drive / gear box)

 

 

 

You can find parts list here:

 

http://montesa4rt.nl/

 

 

Edited January 6, 201610 yr by guys

My shop manual and these postings disagree on whether the stick is screwed in or not. However, the manual says that an oil and filter change require 440 cc to replenish the engine oil. On my bike, 440 cc makes the level read on the upper mark with the stick screwed in. I think my problem started on my first oil change when I kept adding oil until the level reached the upper mark with the stick out and I hadn't measured the total added. It's all getting very fuzzy, if not fussy!

 

It does not matter really how you do it, but what conclusion you conclude from it. Without the dipstick screwed in, and to the full mark, makes it too full. It should be around the middle. With it screwed in, the full mark will result in half of the dipstick unscrewed.

It does not matter really how you do it, but what conclusion you conclude from it. Without the dipstick screwed in, and to the full mark, makes it too full. It should be around the middle. With it screwed in, the full mark will result in half of the dipstick unscrewed.

I, and I suspect most 4RT owners have done it always as the manual prescribes, without any problems:

 

 Start the engine and let it idle for a 3 minutes. Stop the engine and wait 3 minutes. Support the motorcycle upright on a level surface.

Remove the oil filler cap/dipstick on left crankcase and wipe the oil with a clean cloth. Insert the dipstick without screwing it in, remove it and check the oil level.

 

Going by the volume (440cc) is inaccurate because you don't know how much oil is left in the engine after draining.

which seal are you meaning?

The bike can throw oil out of the breather if its been upside down.

Never heard of it ending up in the gear box.

Any signs of oil on the sump guard?

Maybe top up a little and keep an eye on it.

 

Thanks JR.  I don't know which seal as it's hard to tell from the preceding posts, which is where the lost link would have been handy.

 

It has not been upside down and I recall a pipe near the radiator additional to the expansion which (without the bike in front of me now) I assume to be an engine breather but I saw no sign of oil from there.

 

There's been too much mud about at recent events to see oil on the sumpguard but there was no trace in the water when washing though once I get the wheels back in it I intend to drop the guard and look at the casings.

 

Top up to full and monitor was going to be my course of action if no leak found - no point tearing things apart until I am sure that needs to be done.

I, and I suspect most 4RT owners have done it always as the manual prescribes, without any problems:

 

 Start the engine and let it idle for a 3 minutes. Stop the engine and wait 3 minutes. Support the motorcycle upright on a level surface.

Remove the oil filler cap/dipstick on left crankcase and wipe the oil with a clean cloth. Insert the dipstick without screwing it in, remove it and check the oil level.

 

Going by the volume (440cc) is inaccurate because you don't know how much oil is left in the engine after draining.

 

Almost all motorcycles state that you must not screw it in, but that was not my point. You can even measure it with a ruler if you want (ok, you need a tiny one), but the conclusion is far more important. Normally reading a dipstick, the oil should be between two marks, min and max, and measured by a certain way (which you descripe above). The important thing is to have the right amount of oil in, and if you can measure that with your tongue is good aswel

I've damaged the generator cover before by landing hard on the sump guard, the guard then bends and puts pressure on the rubber between the guard and the gen cover, bending some of the lower cover bolts and the cover itself. New gasket, bolts and a sledge hammer on the sump guard fixed it.

No external leaks so I'll probably spend the next week trying to get the sumpguard back on