Help with tuning.

MichaelB said:
Could the reed be in backwards not allowing the crankcase to vent?
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The reed is working correctly, removed and inspected, about an oz of oil in the downstream side.
concours said:
As an aside, have you VERIFIED the crankcase venting SYSTEM? Plumbing? Etc?
Hose routing?
The symptoms described, images shown, scream to me:
A dry sump engine with a flooded crankcase. Figure out why.
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Verified the hose routing and the reed valve.
concours said:
elefantrider said:
Help with tuning.
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baz said:
I once had something similar happen on a 750 commando I once owned
The very tip of one the oil control expanders was missing/broken off
This caused it to partially overlap like the phone above
This was causing really excessive smoking
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THIS! Thanks Elefandrider and BAZ. I have one in each condition, it had slide under the other side, the tip is missing. The right side piston, the offending right side is the one puking oil.

Now we are getting somewhere! Thanks to all for helping me.
 

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I have a question about gaskets. The bike is a Combat, the deck is not shaved. The cam is a JS-1. How much total gasket height do I need?
Had .062" copper base and an .042" composite head gasket. = .104"

I have an .020" copper base and '062" copper head gasket. = .082"

Am I cutting it too close?
How do I check it? I imagine its bolt the head down and use some clay and measure.
What's a safe clearance cold?
 
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Fast Eddie said:
You say the oil way through the barrel is clear, but in the picture it looks like the barrel has left a mark that shows the barrel hole was misaligned and was ‘eye-lidding’.
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brian4.2 said:
Looks like a bad stamping of the base gasket. I didn't catch it on install. This is significant blockage.
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Brian I might be wrong but you may possibly have misunderstood Fast Eddies posting to me he is talking about castings and not gaskets ?

I also took a close look at the photographs of gasket and oilways and would agree with Fast Eddie that from gasket markings it does look like the oil holes in the castings are misaligned.

This would appear to be in addition to having been supplied the wrong gasket.

If it were me I'd be checking hole alignment in both castings as they come together - put a tight fitting rod in the barrel hole and lower the barrel down onto the crankcases to see how they align.

I could be off beam here but worth checking while all is apart - quick and easy to do
 
Grandad said:
Brian I might be wrong but you may possibly have misunderstood Fast Eddies posting to me he is talking about castings and not gaskets ?

I also took a close look at the photographs of gasket and oilways and would agree with Fast Eddie that from gasket markings it does look like the oil holes in the castings are misaligned.

This would appear to be in addition to having been supplied the wrong gasket.

If it were me I'd be checking hole alignment in both castings as they come together - put a tight fitting rod in the barrel hole and lower the barrel down onto the crankcases to see how they align.

I could be off beam here but worth checking while all is apart - quick and easy to do
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Yes apart from the wrong gasket being fitted ....the bruising of the gasket from the barrels is a concern that needs to be checked from the head to the bottom end for completion.
 

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Grandad said:
Brian I might be wrong but you may possibly have misunderstood Fast Eddies posting to me he is talking about castings and not gaskets ?

I also took a close look at the photographs of gasket and oilways and would agree with Fast Eddie that from gasket markings it does look like the oil holes in the castings are misaligned.

This would appear to be in addition to having been supplied the wrong gasket.

If it were me I'd be checking hole alignment in both castings as they come together - put a tight fitting rod in the barrel hole and lower the barrel down onto the crankcases to see how they align.

I could be off beam here but worth checking while all is apart - quick and easy to do
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Thanks Grandad and KS, I understand now and will measure and inspect it as soon a my garage warms up, still snowing here. Nice photo.

I am looking for both gaskets but I'm unsure of height or combined thickness.
 
brian4.2 said:
I have a question about gaskets. The bike is a Combat, the deck is not shaved. The cam is a JS-1. How much total gasket height do I need?
Had .062" copper base and an .042" composite head gasket. = .104"

I have an .020" copper base and '062" copper head gasket. = .082"

Am I cutting it too close?
How do I check it? I imagine its bolt the head down and use some clay and measure.
What's a safe clearance cold?
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Why don't you ask the person who sold you these parts??
 
brian4.2 said:
Thanks Grandad and KS, I understand now and will measure and inspect it as soon a my garage warms up, still snowing here. Nice photo.

I was able to pass this .165" dowel through the barrel and into the head 2", not a straight shot. The casting drain hole is .180"
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It appears there are at least two errors in engine assembly here.
A stop, review, inspect, research everything is in order, for safety (of your checkbook)
 
brian4.2 said:
I did Chris, was very helpful. I am good at.082"
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Whatever your ignition advance, fuel octane ratio, exhaust system and compression ratio might be, they need to stay constant while you jet the carbs to suit them. At the optimum, they are all in balance with eaxch other. Only change one thing at a time, and the final adjustment always nreds to be the jetting.

If you have a dyno, you can gert the jetting roght with an oxygen meter, and move the ignition advance unti you get maximum torque. But most people probably never do that.
 
Hi Brian, you mention putting a rod through the barrel and into the HEAD when surely the possible issue is at the base of the barrel where it meets the crankcase.

From the original photographs it looks like ( due to the circular mark on the gasket ) that the oil hole in the BASE of the barrel doesn't line up fully with the oil hole in the crankcase.

Imagine bolting your carburettor to the cylinder head, simple job of course but think what would happen if the original machining was wrong and the carb was offset by 3/4" ...... the engine would be starved of fuel / air on the one cylinder.

The greater the offset the less " flow "

What should happen is that ( excuse the simplistic description ) the exit hole of the carburettor should exactly line up with the inlet hole on the head casting in order to get the best possible " flow "

Similarly you should have the same perfect hole alignment of the oil holes, if oil cannot flow away from the head you get oiling problems.

Get a piece of rod / wooden dowel / bolt shank of the same diameter as the oil hole so that it fits snugly in the barrel and has a protrusion of say 1/2" .... when you lower the barrel down onto the crankcase ( no gasket ) you should see exactly how the two holes align with each other and if lucky the rod / dowel / shank will enter into the crankcase hole.
Some very small misalignment will be ok as long as the majority of the holes are together.

Another way :

First measure the distance from the portion of the barrel that sits inside the crankcase to the edge of its oil hole
Now measure from the inside edge of the crankcase to the edge of the oil hole
Comparing these measurements will tell you how well or otherwise the holes align.

I realise that some of the issue could be from using the wrong gasket which obscured the drain hole and that a correct gasket could get you running well again but if there is an issue of hole alignment it would be better to find out now before final assembly.

Time is cheap and ultimately less stressful.

As an aside and just thinking out loud .... often you hear folks say about oiling and that after fitting new valves / guides / seals they still have an oiling / exhaust smoke issue ..... the puzzlement often being put down to British bike " character " as a way of excuse ...... this potential issue of yours could be the answer for many a brit bike owner.

Geoff :)
 
British bikes are usually very logical in their construction. You should have no problem in building them correctly, as long as you think about why things are the way they are. With old British bikes it is possible to start with nothing and manufacture the whole bike. One of my friends wanted an Anzani JAP - so he made one. When he makes a cylinder head, he carves the ports out by hand.
In life, our achievements are only limited by our mindsets. All we ever need to do is start at point A, and progress steadily towards point B. Money is only an obstacle if you let it be one. We all need to be patient.

 
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acotrel said:
British bikes are usually very logical in their construction. You should have no problem in building them correctly, as long as you think about why things are the way they are. With old British bikes it is possible to start with nothing and manufacture the whole bike. One of my friends wanted an Anzani JAP - so he made one. When he makes a cylinder head, he carves the ports out by hand.
In life, our achievements are only limited by our mindsets. All we ever need to do is start at point A, and progress steadily towards point B. Money is only an obstacle if you let it be one. We all need to be patient.

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There is some truth to this. Paul Brodie builds entire bicycles/motorbikes. He's build classic motorzied bikes, steam bikes, board track racer machines, all from studying early photographs. Even makes his engines from lumps of metal.
 
Tornado said:
There is some truth to this. Paul Brodie builds entire bicycles/motorbikes. He's build classic motorzied bikes, steam bikes, board track racer machines, all from studying early photographs. Even makes his engines from lumps of metal.
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I love the Paul Brodie and Alan Millyard stuff on YouTube
 
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