Crankcase Breather?

[landyandy]

Hi,

Just a quick couple of questions ...

1) Where will I find the crankcase breather on an RD04 (I have an over-pressurising problem)?

2) Anyone know if the RD07 engine is a straight swap for the RD04, particularly carbs and engine to frame/swingarm mounts?

[YEN_POWELL]

It's the biggest/fattest tube hanging out the bottom with all the other'ns. It's supposed to have a plug in the end, although that might have been dumped by now. It oozes white gunge which is never attractive even in the right light.

[landyandy]

Hmm ... any ideas where it affixes to the crankcase? I'm checking everything I can think of before disassembling the engine again, as I'm over pressure somewhere.

[YEN_POWELL]

Apears to be coming out of the top of the rear cylinder, into the airbox(RD07 model) then from the airbox downwards to the drain plug. I assume that the RD04 engine has exactly the same brassy coloured pipe coming from it's rear cylinder top but with the pipe running down hill to the underseat airbox.

[landyandy]

Bizarre. My air filter is getting a soaking in oil - seems an odd arrangement for the breather to go into the airbox, but there you go, I'm not an engineer.

I'll have to have another look at it next time I'm sitting on the toolbox.

[YEN_POWELL]

You have obviously refused to buy lucky heather recently. Go with the flow and convert to a foam filter. This would then be automatically oiled. Are you sure you've not overfilled the sump? How do you check the oil, do you have a centrestand?

[landyandy]

I checked the oil level by filling it with 3.5 litres after the engine was rebuilt. When I noticed it was blowing out so much oil, I rechecked it using the dipstick with the bike level (no centrestand).

I then redrained it, and out came about 2 litres, so I filled it a bit at a time until it was mid way between min and max.

I do wonder if when I rebuilt the engine, I lined the piston rings up with each other, rather than staggering them.

Oh well, I'll have a look when I get the thing to pieces.

[landyandy]

Ok - it might have been 3.2L of oil - can't remember now ... either way, it was the amount stated in the workshop manual.

I think I'm hoping against hope re. the breather unfortunately. There's way too much oil getting into the carbs, and when you load the engine, it seems to drop down to 1 cylinder above about 3.5k revs. It's all a bit of a mystery.

Any ideas?