Exhaust port leaks

[Wevil Kenevil]

When building my yd 100 lower and Ld100 top end , I wasn't paying attention to the thickness and diameter of the exhaust port and when I went to put my pipe on (f2 thrust) there was very little mating surface between the pipe flange and cylinder. 3.5 mm thick in some places.... ( No, there are no pipes that fit perfectly over this monstrosity of a hole. It's like a BT cylinder AND A YD CYLINDER had a messed up baby... It's not one or the other. )

So I suffered from horrible exhaust leaks. So what I did was take some metal putty from harbor fright and built up the area around the outside of the exhaust port.

If you can, do this before you run the head so that it's not all greasy and nasty and yuck so the putty sticks good and take a small file and rough up the area you are going to fortify around the port just for good measure!

I don't have any blow by or exhaust leaks now... Yay!

There may be other ways to do this but I am unaware of them.

Good luck!

 

[Tony01]

When building my yd 100 lower and Ld100 top end , I wasn't paying attention to the thickness and diameter of the exhaust port and when I went to put my pipe on (f2 thrust) there was very little mating surface between the pipe flange and cylinder. 3.5 mm thick in some places.... ( No, there are no pipes that fit perfectly over this monstrosity of a hole. It's like a BT cylinder AND A YD CYLINDER had a messed up baby... It's not one or the other. )

So I suffered from horrible exhaust leaks. So what I did was take some metal putty from harbor fright and built up the area around the outside of the exhaust port.

If you can, do this before you run the head so that it's not all greasy and nasty and yuck so the putty sticks good and take a small file and rough up the area you are going to fortify around the port just for good measure!

I don't have any blow by or exhaust leaks now... Yay!

There may be other ways to do this but I am unaware of them.

Good luck!

Exhaust pipe gaskets are specially made of a high temp composite material to not blow out with the heat and pressure. I’ve used copper sheet with success. The pipe and motor must be port matched for best performance.

 

[Wevil Kenevil]

The problem I was having was not enough surface to really support the f2 pipe and get a good deal due to the whole weight of the pipe being put on two bolts on the exhaust. Building up the area around the outside of the port seems to have stabilized it.

The gaskets I got were crap I guess. There was no metal wafer sandwiches in it making it fall apart when the pipe was loosened or was removed. I like the all metal ones . They are rugged.