stay_upright
New member
Have just finished putting the top end together but had a few niggling doubts about everything was well..
When running - idling - there still seemed to be a lot of mechanical noise at a guess could the big end be worn even though I checked it? Again - how obvious is it when the big end it worn?
After about 4 to 5 starts and restarts with the choke on the pipe has about 1/4 of a cup of fuel/oil in it. It certainly contained a reasonable amount of oil as it was quite a bit thicker than fuel.
After 1 start and coming quickly off the choke there was about say 5mm worth of oil in the pipe.
I changed the oil and pulled out 650ml though the engine was warm and not 'hot' I put 900ml in, level looked approx OK in the window.
I pulled the crankcase drain and there was about 1/8 to 1/4 cup of oil in there - it looked like clean oil (maybe the stuff I had just put in)..
Looking in the exhaust port I found 2 pieces of brown rubber approx 3mm x 2mm, also later I found one piece near the neck of the pipe again about the same size.
There were also some small flecks of aluminium on top of the piston which I fould by running my finger over the top and it stuck to my finger.
It also felt as if at one point the engine was running tighter or perhaps partially seized though not sure if this is my imagination.
There was some evidence of white emulsion in the RH PV assembly where the rod goes on the inside of the case and a bit near the cylinder stud/nut there.
My guess is the bits of rubber are a crank seal or similar hence only pulling out 650ml oil plus oil in the bottom of the crankcase and the pipe... I can't think why it still sounded loud mechanically though?
My guess also is any damage has only occurred after the rebuild, the reason being if I was loosing that much oil the last time(s) I used the bike surely it would have used all the gearbox oil?
I'm wondering if maybe when I lifted the PV actuating rod to reinstall it some of the ball weights dropped out (is that possible) and have been rattling around the crankcase and damaged the seal?
Is there any possibility I don't have to pull the bottom end apart?
Also I was going to try and check the PV rod moved correctly when revved, how do you do this with the cover removed doesn't the exhaust gas just come out there?

When running - idling - there still seemed to be a lot of mechanical noise at a guess could the big end be worn even though I checked it? Again - how obvious is it when the big end it worn?
After about 4 to 5 starts and restarts with the choke on the pipe has about 1/4 of a cup of fuel/oil in it. It certainly contained a reasonable amount of oil as it was quite a bit thicker than fuel.
After 1 start and coming quickly off the choke there was about say 5mm worth of oil in the pipe.
I changed the oil and pulled out 650ml though the engine was warm and not 'hot' I put 900ml in, level looked approx OK in the window.
I pulled the crankcase drain and there was about 1/8 to 1/4 cup of oil in there - it looked like clean oil (maybe the stuff I had just put in)..
Looking in the exhaust port I found 2 pieces of brown rubber approx 3mm x 2mm, also later I found one piece near the neck of the pipe again about the same size.
There were also some small flecks of aluminium on top of the piston which I fould by running my finger over the top and it stuck to my finger.
It also felt as if at one point the engine was running tighter or perhaps partially seized though not sure if this is my imagination.
There was some evidence of white emulsion in the RH PV assembly where the rod goes on the inside of the case and a bit near the cylinder stud/nut there.
My guess is the bits of rubber are a crank seal or similar hence only pulling out 650ml oil plus oil in the bottom of the crankcase and the pipe... I can't think why it still sounded loud mechanically though?
My guess also is any damage has only occurred after the rebuild, the reason being if I was loosing that much oil the last time(s) I used the bike surely it would have used all the gearbox oil?
I'm wondering if maybe when I lifted the PV actuating rod to reinstall it some of the ball weights dropped out (is that possible) and have been rattling around the crankcase and damaged the seal?
Is there any possibility I don't have to pull the bottom end apart?
Also I was going to try and check the PV rod moved correctly when revved, how do you do this with the cover removed doesn't the exhaust gas just come out there?
