Oil leak

Maestro, SEI-V
Emmohaswheelsagain
Posts: 358
Joined: 28 Jun 2008 21:13
Location: Lincolnshire

Oil leak

Post by Emmohaswheelsagain »

Has anyone had any issues with a leaking dip stick?
I ask because I am trying to trace a major oil leak.
The pool of oil came from the right side of the motor, which led me to believe that it may be the seal behind the front sprocket.
On checking the area around the sprocket it was difficult to come to any conclusions, naturally the chain sprays that area with gear oil.
I have cleaned the area and re inspected the area after running the engine, no sign of a leak.
The leak formed a puddle under the bike in no time at all.
On inspection the o rings on the dip stick have hardened which makes it rock in the filter hole.
Could that be the source of such a major leak?

Thanks

Paul
mbmm350s
Posts: 666
Joined: 22 Jun 2018 10:18
Location: Reading UK
Location: Berkshire UK

Re: Oil leak

Post by mbmm350s »

Emmohaswheelsagain wrote: 19 May 2023 10:36 Has anyone had any issues with a leaking dip stick?
I ask because I am trying to trace a major oil leak.

On inspection the o rings on the dip stick have hardened which makes it rock in the filter hole.
Could that be the source of such a major leak?

Thanks

Paul
Hi Paul,
possibly an oil leak from the dip stick, in this case you might smell burning oil if you have an exhaust with a balance pipe.
There are as you say of course other sources to check such as the gearbox sprocket oil seal and crank oil seal.
AND the sump plug!!! Crank case bolts too come to mind too, there is one quite near to the sprocket.
However its easy to eliminate the dipstick if you use the O-rings of the correct size,
please note these are from the OR series which is an Italian standard like the BS616 series,
they are not based on 2.5mm section but on 2.62mm, a common mistake to make is assuming 2.5mm and use these which will be too small.
Here are the correct part descriptions which you can get from Simply bearings

BS616 2.62mm Section 15.08mm Bore NITRILE 70 Rubber O-Rings

This cross references to OR 119 (OR119) 2.62 mm 15.08 mm

Hope that helps

Cheers Mark
Emmohaswheelsagain
Posts: 358
Joined: 28 Jun 2008 21:13
Location: Lincolnshire

Re: Oil leak

Post by Emmohaswheelsagain »

Thanks Mark, I will order the replacement O rings from Simply Bearing just to make sure, they look passed their sell by date, very crusty.
At the same time I will order in the necessary oil seals, you can never have enough spares!
Hopefully I will locate the source of the problem, once I had a chance to investigate further.

Thanks again.

Paul
3potjohn
Posts: 1243
Joined: 02 Jun 2007 13:58
Location: Devon

Re: Oil leak

Post by 3potjohn »

The first time I rebuilt my engine about 15 years ago I made a mistake sealing the two hidden bolts behind the rear cylinder area on the crankcase. Until the first test ride that is when a prodigious Trident - like leak occurred from the right hand cover. I had to pull all the clutch side cases off, disturbing the gasket and seals.
Nowadays I make double sure with a very thin wipe of threebond as well as the copper washers.
Lets hope just an oil seal issue.
Still you can run with the generator cover off to check the source.
John
Stempy
Posts: 135
Joined: 07 Jul 2020 08:23
Location: Grimsby

Re: Oil leak

Post by Stempy »

Have you checked the engine breather is not blocked or the tube kinked ?
Emmohaswheelsagain
Posts: 358
Joined: 28 Jun 2008 21:13
Location: Lincolnshire

Re: Oil leak

Post by Emmohaswheelsagain »

That is one of the possible issues.
Never had a problem before with my other Morini’s but then again this particularly bike is throwing up plenty of left field issues.
I will order the necessary o rings and oil seals and look to replace the breather pipe.
This is a good bike, I just need to work through these faults and hopefully I can then enjoy some miles.😀
Emmohaswheelsagain
Posts: 358
Joined: 28 Jun 2008 21:13
Location: Lincolnshire

Re: Oil leak

Post by Emmohaswheelsagain »

Dip stick is now a good fit after replacing the O rings.
I have checked the blue book and the oil level should be checked with the dip stick in position.
What does this mean? I assume fully pushed in?
Surprisingly measuring in this way the oil is above the maximum, indeed well over the maximum.
Next step is to drain the oil and refill to the measure on the dip stick.
According to the blue book this should be 3 litres.
I have also removed the breather pipe, this was too long, so when fitted there was a kink in the pipe (thanks for the tip Stempy).
Not sure at this stage the significance of this, but I will replace with a pipe of the right length.
Would radiator hose cut down to size be ok?
Hopefully this will resolve both the oil leak and the running issues.

Thanks

Paul
norbert
Posts: 750
Joined: 15 May 2007 15:15
Location: Lübeck/Germany

Re: Oil leak

Post by norbert »

Obviously there was too much oil inside.
It´s 2,5 l (if you want a little more), 3 l is too much!
Emmohaswheelsagain
Posts: 358
Joined: 28 Jun 2008 21:13
Location: Lincolnshire

Re: Oil leak

Post by Emmohaswheelsagain »

After further investigation the problems are beginning to emerge. After draining the sump it is clear that all is not well.
In total nearly 5 litres came out of the sump.
I checked the invoice and I was charged for 2 1/2 litres as you would expect so I find it difficult to assume that the sump was overfilled.
There was a strong smell of petrol and on close inspection I could see clear traces on the surface. The oil has clearly been contaminated I assume by fuel passing the rings and dropping into the sump. That would account for the rough running and the fowling of the front plug. Unusually at no time has the bike smoked. When checking the filter I have found no sign of internal damage but once the barrels and heads come off I will learn the true extent of the problem. Whatever the issue I will have to pause the work as I do not have the room right now to strip the engine down. Once this is done I will no doubt have to search for spares. Let’s hope the destination is worth the journey.
norbert
Posts: 750
Joined: 15 May 2007 15:15
Location: Lübeck/Germany

Re: Oil leak

Post by norbert »

Obviously while parked at least one fuel tap was open and a float valve in one of the carbs didn´t close. That´s the way the fuel gets into the crank case :wink: and it would also happen with perfect segments on the pistons.
Up to now I don´t see any reason to strip the motor (at least for that reason). Make sure that the fuel taps close when closed, get you some new needles/valves for the floats and adjust the fuel level in the carbs. That´s a quite cheap problem :D
mbmm350s
Posts: 666
Joined: 22 Jun 2018 10:18
Location: Reading UK
Location: Berkshire UK

Re: Oil leak

Post by mbmm350s »

Hi Paul,

I have had jammed floats on two Morinis in the last two years, which was never a problem before. This seems to occur only if the bike is left standing.
The fault is it seems caused by excess swelling at the seam where there is flashing on the white or brown floats that are the hollow type caused probably by ethanol in the fuel. I have filed them all down now an no problems have reoccurred.
Providing there are no other problems personally I would not dismantle the engine, change the oil and ride, always keeping an eye on the fuel,
and always turn off the petrol. If you leave it standing for some time check the oil level and if there is any resistance on the kick start, take the plugs out and kick over to expel the excess fuel.
I have also had a float valve come loose, so double check all float valve seats are secure.

Check also if any taps are not stopping the fuel in the off position and replace as necessary.

Its also not surprising if there were oil leaks if there was 5 litres in the sump.

I would squirt some oil down the bores and kick over a bit before starting to help the rings to seal.

Probably controversial but...
If you take it apart now then there will be all manner of things that you will think to fix and a great expense. Me I would just ride.

Mark
norbert
Posts: 750
Joined: 15 May 2007 15:15
Location: Lübeck/Germany

Re: Oil leak

Post by norbert »

That´s true! I think the problem with sticking floats happen much more frequently with the ridges of the "new" white plastic ones
Emmohaswheelsagain
Posts: 358
Joined: 28 Jun 2008 21:13
Location: Lincolnshire

Re: Oil leak

Post by Emmohaswheelsagain »

All good advice, I have checked the fuel tap and off is definitely off. Certainly when the bike has been in my ownership I have always turned off the fuel when parked. When I purchased the bike it had been stored for 3 years, hence the decision to have the bike checked over by a well known Morini specialist. Unfortunately the problem was not identified at the time of service, despite 8 hours of work. Fortunately for me I have done only a couple hundred miles, preferring to sort out the running issues before testing the bike fully.
If your assumptions are right I may have avoided an expensive breakdown. I will replace the needles and needle valves which are relatively inexpensive, the floats themselves appear good although I did previously replace the float pins which were seriously marked.
I will then replace the oil with some of Halfords best 10/40 making sure to squirt some down the bores to help seal the rings. Hopefully this will resolve the running issues although you can be sure that I will continue to check the oil levels for any contamination.
Thanks again for all your help.
Regards
Paul
MickeyMoto
Posts: 2415
Joined: 22 Nov 2008 17:41
Location: Even further oop North

Re: Oil leak

Post by MickeyMoto »

Hello Paul,

Did your bike lock up when starting it? I have had it where I left a tap open over night on a non Morini, the float valve did not cut off and because the engine stopped with the inlet valve open, the fuel filled the combustion chamber. The next day, the bike was locked. Removed plugs, pressed starter and a stream of petrol shot out of the plug hole. As petrol is not very viscous it will leak past the rings anyway. I rode the bike home 200 miles. I was lucky, as this can lead to a bent con rod.

As to the oil, I would fill with a cheaper 20/50 mineral oil (like we used to use back in the 80s, I think the Halfrauds classic 20/50 is green like the old Duckhams oils) run it, drain it. Try this a couple of times before using more expensive oil.
mbmm350s
Posts: 666
Joined: 22 Jun 2018 10:18
Location: Reading UK
Location: Berkshire UK

Re: Oil leak

Post by mbmm350s »

Hi Paul,

With the floats jamming sometimes you can see like witness marks on the float bowl, at the front or sides.
Do you have white or brown type hollow floats or the solid brown floats. The problem is most apparent with the white floats.
For sure its a good idea to change the needles and needle valve seats, these are available with Viton tips which are supposed to be more suitable for petrol containing ethanol.

It could have been crud under the needle valve rather than jammed float, might be worth checking the fuel tank tap filters are present,
and complete.

I am with Mike here use some mineral 20/50 and treat it like running in for a few hundred miles. The concern that some of the crud in the crank oil ways has been flushed out, but given this is usually rock hard and has to be drilled out I thinks its minimal risk. The rings will reseal.

The bane of Morinis and many bikes is lack of usage, too precious to use, so do the equivalent of tens of thousands of miles damage by leaving them to corrode in garages and in sheds to rot.

To be fair, its difficult when bringing a bike that's been off the road back into use as you really need to do several shake down runs, and I always treat any bike gently for a while after its been unused for a number of months. Unless the tanks was drained and dried out there's always stale fuel, water in float bowls, condensation in rockers etc to be blown away.

Cheers
Mark
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