ET: Engine (Twin) 1954 Black Shadow Oil Fouling on front Cylinder only, any checks?

JohnA

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Looks like oil is getting into the intake, does anyone concur? Looks like a summer stripdown - guarantee might not be applicable but I will wait for a response from seller before I dive in and discover more Vincent engineering.
 

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BigEd

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I may still be wrong but I think this is where I am headed, I do only get smoke when I kick it hot as in when it has stalled. Kicking cold just clears the oil with the tickle and turning the motor I think. Some one has modified the rocker feed bolts - Im wondering if they also have a used seals which have gone faulty, the bike was unused for a long time.
The oil seals usually do a pretty good job of controlling oil getting down the valve guides so maybe you do not have oil seals fitted or maybe not fitted correctly. Before diving in too far would it be worth trying a restrictor wire in the front inlet rocker feed bolt to see if that makes a difference?
 

JohnA

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Will that be ok with the modified rocker feed bolts, I take it the oil passes through the old threads with this mod?
 

davidd

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That is a locking rocker feed bolt and I am not sure that the hole is big enough to get a meter wire through. The hole at the top tends to be smaller and deliver less oil to begin with. The lower feed can either be one or two holes on the first thread on the body side. The nut should not pull up tight enough to cover them.

I would guess that it is a sloppy guide in combination with no draining.
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Not very pretty, but effective.

I would probably install a sealed guide, but draining the guide area might be effective also.

David
 

JohnA

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Thanks David, On closer inspection I can see the feed holes. I will try to take in - slowly -what you're saying about improving drainage but it seems I will need to take the head off.
 

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Cyborg

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The photos in post 11 look a little odd to me, but I'm not the resident expert. Maybe it just the photo, but the seat looks like it protrudes into the port more than normal. Usually just a small amount if any from what I have seen. As if the head was ported at one point and then the seat was replaced at a later date. Not that you are going to be racing it, so not worth worrying about flow, but is worth having a look at it if and when you pull the head off.
 
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JohnA

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The photos in post 11 look a little odd to me, but I'm not the resident expert. Maybe it just the photo, but the seat looks like it protrudes into the port more than normal. Usually just a small amount if any from what I have seen. As if the head was ported at one point and then the seat was replaced at a later date. Not that you are going to be racing it, so not worth worrying about flow, but is worth having a look at it if and when you pull the head off.
Interesting,. I will most likely take the head off and get some expert to look
 

Sakura

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Why strip a bike in the summer? Oil fouling on the front cylinder is a well known Vincent fault. Fit a hotter plug, use the bike for the summer and repair over the winter.
 

JohnA

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If I do manage to find a plug to cope I'd be surprised but leave it until September and I won't have any chance of guarantee not that I've had an email reply from the vendor yet. But things like this niggle me, just knowing something's wrong.
 
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