Crankcase Breather for Economy?

[bikedave99]

I was reading on Sean Morley's website about his Muscle Jet Kit, and he had some verbiage in there about how the crankcase breather that is routed to the oil fill cap helps with ring seating, power and economy. Now, obviously it is installed when the rest of the kit is in place and bigger headers are in the game. My question is, has just the breather ever been installed on an otherwise stock bike? Would it improve economy? Just thinking out loud.

 

[one2dmax]

Yes, we have installed it on an otherwise stock bike. Bike seemed to pull harder and the process works better the higher in rpm you go. Not sure if it will add much overall economy as i've not tried measuring just that.
Sean

 

[gamorg02]

sean, is there any reason i can't remove the puke going up to the airbox? just have it dump back into crankcase?

 

[bikedave99]

Yes, we have installed it on an otherwise stock bike. Bike seemed to pull harder and the process works better the higher in rpm you go. Not sure if it will add much overall economy as i've not tried measuring just that.
Sean

Interesting, I might try it and see. What would you take for just the hose-barbed filler cap?

 

[4gasem]

You'll need a T fitting as well and some hose. He can get all of that for you which would make life easier IMO.

Chris

 

[bikedave99]

You'll need a T fitting as well and some hose. He can get all of that for you which would make life easier IMO.

Chris

True enough, I was thinking about just an extra oil fill cap, cutting off the twist tab, and tapping it for a hose barb. But, then it would be hard to remove, unless I knurled the edges. Just getting his would be a lot easier. Looks like a 1/2" ID hose, is there a science to that size?

 

[4gasem]

True enough, I was thinking about just an extra oil fill cap, cutting off the twist tab, and tapping it for a hose barb. But, then it would be hard to remove, unless I knurled the edges. Just getting his would be a lot easier. Looks like a 1/2" ID hose, is there a science to that size?

Nope! Sean has the caps custom milled. He used to do just as you want to do but it isn't nearly as clean of a job when done. I just thought he could ship it all to you and you'd be good to go.

Chris

 

[bikedave99]

Nope! Sean has the caps custom milled. He used to do just as you want to do but it isn't nearly as clean of a job when done. I just thought he could ship it all to you and you'd be good to go.

Chris

Nice, thanks for the quick responses Chris! I'll just wait for Sean to weigh back in then! Could be an interesting little experiment..

 

[one2dmax]

Yea, I think I was charging $50 for the billet cap, hose "T", and section of 1/2" line. You could make one yourself for much cheaper as you noted. The biggest cost for me is the billet cap. I don't remember if I have any used stage seven caps around but might be a little cheaper if so.

The "T" needs to be 3 way 1/2" fittings. Go to the instructions on our website and you will get an idea what needs to be done.

Sean

 

[bikedave99]

Yea, I think I was charging $50 for the billet cap, hose "T", and section of 1/2" line. You could make one yourself for much cheaper as you noted. The biggest cost for me is the billet cap. I don't remember if I have any used stage seven caps around but might be a little cheaper if so.

The "T" needs to be 3 way 1/2" fittings. Go to the instructions on our website and you will get an idea what needs to be done.

Sean

Thanks Sean, looking on Fleabay, there are a lot of nice billet oil filler caps for a number of different yamaha bikes. I am pretty confident that there are a ton of bikes that share the Vmax's oil cap, but I'm not sure which ones, I did a partnumber check on a couple and they weren't exactly the same but I'm sure something has the same threading. I'll have to do some guess and check.