Oil leak - need to remove horizontal cylinder head and cylinder

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dessmo
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Oil leak - need to remove horizontal cylinder head and cylinder

Post by dessmo » Mon May 15, 2017 12:43 pm

It seems like I have a small oil leakage from the front/horizontal cylinder. The leakage seems to be between the cylinder head and cylinder. So I guess I have to replace the gasket. Based on the workshop manual it seems straight forward, but I would be interested in any tips on what to don/not do. And should I replace other gaskets during this operation? I guess some may be ruined during the operation. And are thee other things I should do/replace while I am on to this. Would appreciate any input from the experienced crowd.

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Re: Oil leak - need to remove horizontal cylinder head and cylinder

Post by wdietz186 » Mon May 15, 2017 4:07 pm

There are 2 o rings located around dowels that seal the oil passages. You probably should replace the exhaust gaskets and possibly the carb insulators too. the carb insulators tend to leak vacuum when they get old and shrink. Being the horizontal cylinder it is an easy job, Exhaust, carb, tach cable, four nuts and the head is off. The exhaust nuts can be reluctant so the proper tool is strongly advised and setting the cylinder on top dead center[compression stroke, both valves closed] will make removing the head a bit easier. Mark the cam gears because if set at the position the dots on the gears line up [TDC on the vert. cyl.] the intake valve will be open and can move making re installation a touch more difficult. Try not to move the cylinder when removing the head so the sealing between the cylinder and block will remain undisturbed. It is all nuts and bolts, no magic involved.

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dessmo
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Re: Oil leak - need to remove horizontal cylinder head and cylinder

Post by dessmo » Mon May 15, 2017 11:19 pm

Thanks for the tips wedietz. I am looking for the gasket between the head and the cylinder, but can't find it. The only gasket I am finding is the base gasket. Looking at the bike it seems that there is a gasket, so I am i bit confused. Should there not be a gasket between the head and the cylinder?

Parts cylinder head: http://www.ducaticlassics.com/Parts/Mod ... 77-82SD07/

Parts cylinder http://www.ducaticlassics.com/Parts/Mod ... 77-82SD04/

So maybe I have to examen the oil leak once more to be sure where its leaking from.
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Re: Oil leak - need to remove horizontal cylinder head and cylinder

Post by wdietz186 » Tue May 16, 2017 6:27 am

There is no gasket between the head and the cylinder only two o rings that seal the oil passages. The cylinder sleeve to head junction is a spigot fit and seals just fine if everything is clean and flat. I have seen on occasion a stud pulling out of the case. You could try checking the cyl. nut torque [30 lb.ft.] sometimes they will take the torque only to loosen when the engine heats up. The solution to that is drilling the case and using a Helicoil or Timesert to repair the thread.

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Re: Oil leak - need to remove horizontal cylinder head and cylinder

Post by BevHevSteve » Tue May 16, 2017 7:18 am

assuming you are talking about your Darmah, there is no gasket between cylinder and head, only orings.

https://store.bevelheaven.com/Gaskets-S ... r-to-Head/

If you are going to remove the head, my advise would be to replace the orings on the bevel tube as well as the above. And if you are going to remove the head, really the smart thing would be to replace all the gaskets while you are at it.

I have a complete top end gasket and seal set available, includes literally everything needed from the base gasket up.

https://store.bevelheaven.com/Gaskets-S ... vel-Drive/
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Re: Oil leak - need to remove horizontal cylinder head and cylinder

Post by ducadini » Tue May 16, 2017 10:41 pm

dessmo wrote:
Mon May 15, 2017 11:19 pm
Looking at the bike it seems that there is a gasket, so I am i bit confused. Should there not be a gasket between the head and the cylinder? So maybe I have to examen the oil leak once more to be sure where its leaking from.
Unless You're very sure about the previous owners and/or mechanics, there's NO gasket.
However : sometimes the ignorant mechanic fits one to be on the safe side (although it doesn't help unless because one of the faces isn't very exact machined) or used a tube of sealant.

As stated : nothing complicated (beware of the markings on the bevels at TDC) to change a few o-rings (purchased at the right guy).
When taking off and refitting the exhaust be sure to loosen all clamps and bolts and using some heatresistant anti-grippant to avoid future damage.
Especially on the exhaust nut, which I ALWAYS lock-wired.

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