Author Topic: Dragonfly Timing Chest Oil Leak from Cast Boss  (Read 4778 times)

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Offline BrmBrm

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Dragonfly Timing Chest Oil Leak from Cast Boss
« on: 28 Feb 2015 at 13:32 »
This is partly a very simple question that any Dragonfly owner could answere, but then may get more involved.
Young Dougie has a small (but to big to ignore) oil drip. As he is now too old for nappies and as a dutiful adopted parent I am attempting some basic toilet training.  :wink:
He has a steady oil widdle from the Timing Chest, from the cast boss facing downwards, on the front face and offset to the nearside. Next to the oil filter cap. There isn't a bolt or plug in this hole.
Should there be? If so what thread and length :question:

I haven't had the timing chest off, but would like to know the purpose of this boss.Is it a drain , overflow, or oil level drain? Is the timing chest oil directly level with the sump oil? Or may I have a leaky crankshaft seal (if any) or other?
I don't want to strip the timing chest yet as I wish to run the bike at home and assess what else needs doing :)
Many thanks.

Offline eddie

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Re: Dragonfly Timing Chest Oil Leak from Cast Boss
« Reply #1 on: 28 Feb 2015 at 15:46 »
Hi,
     Do not block that hole - it is the outlet from the engine breather! It is quite common to find that there is a dampness around the breather, but not enough to cause concern. The breather passage is routed from the inside, through the generator cover, into the timing chest, exiting at the bottom of the case. If you remove the generator cover, you will find there is a non return valve - this should be fitted so that it breathes out but not in. Excess oil coming from the breather may be the result of a missing valve or the valve being damaged. Also, be careful when removing the cover as you will also be withdrawing the generator stator and will have to feed the wires into the top of the timing chest. As the cover comes away, tip it so that the bottom comes out more - then you won't damage the support for the cable.

  Regards,
               Eddie.



















Offline BrmBrm

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Re: Dragonfly Timing Chest Oil Leak from Cast Boss
« Reply #2 on: 28 Feb 2015 at 18:37 »
Many thanks Eddie for your very quick reply.
I'll remove the cover and check the breather valve.
Do I need to drain the sump oil first?
Thanks.

Offline eddie

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Re: Dragonfly Timing Chest Oil Leak from Cast Boss
« Reply #3 on: 28 Feb 2015 at 19:08 »
You only need to remove the round generator cover to get to the breather valve. You will only need to drain the oil if you are going to remove the whole timing cover - in which case, it is better to first remove the oil filter. If you are going to make your own gaskets, be sure to punch out the extra holes for the breather and oil feed to the end of the crankshaft!

  Regards,
                  Eddie.

Offline BrmBrm

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Re: Dragonfly Timing Chest Oil Leak from Cast Boss
« Reply #4 on: 28 Feb 2015 at 20:02 »
That's brill Eddie.
Just the generator cover for now.
Basically I bought the bike as a partly completed, but probabley not run much project, off a dealer. And I don't have any prior knowledge of the machine. So I'm treading cautiously! But it does run round my garden. So many thanks for the info and warnings!

Offline BrmBrm

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Re: Dragonfly Timing Chest Oil Leak from Cast Boss
« Reply #5 on: 09 Mar 2015 at 12:06 »
OK, Generator cover removed and generator stator detached.
I've removed the breather valve.
First the screw, then a circular plate with 6 holes and 1 rivet, then a valve roughly made from 0.1mm shim steel cut into 7 segments.
The rivet is fitted in the circular plate but does not go through the home made (presumably) valve segment.
Is the rivet head  fitted between the plate and the valve and intended to hold one segment open, or should it go through a vane to secure it (looks like this on PLATE 4) ?
I'll see if I can get these bits from Spares Dept.
Many thanks,
Dave