Happy New Year esteemed riders,


I have a hose-based external breather on my 07 XL1200L. The stock breather screws have been replaced by banjo fittings and breather bolts from DK Custom. A filter was also included but, screw the epa, I just routed the hose straight to the ground without filter or catch can.


this morning, after a nice long ride, for some reason I stuck my nose near the end of the hose and lo and behold, there was a smell of gasoline coming from there. It's not there when I just start out but I do smell it after riding for a while and the engine is hot.


Does that mean the piston rings need to be replaced?


Thank you for reading.

 

If you have breather bolts with the little screens, and banjo fittings, are the bolts inside your aircleaner? Could vapor from the TB/manifold just back vent through the banjos and out your hose?

If you are worried about your piston rings, do a compression check on both cylinders.

John

 

No not the ones with the little screens. Plus the EBS is completely separate from the air cleaner. Here is a prototype of what it looks like right now:

 

i've has that happen... no idea why.

 

While it does look clean and symmetrical there, I would route the hose(s) down to the bottom of the bike where the smell/vapor will not be a bother.

 

Ok, I can do that. I'll need to educate myself on how to do that first.
So it's not a big red flag to have gas smell outta the breathers?
Yeah, I guess if it's normal operation to have gasoline smell coming out then I'll route it down and be done with it. I am just experimenting right now. If there absolutely should NOT be, then I need to fix the root cause.

 

I'm having trouble seeing where the hoses are routed. In the photo, it looks like there is a single clear hose going from one banjo to the other.

Cristy

 

Yes. That single clear hose arcs from one banjo to the other and has a hole at the top where the hot air exits:When I removed the stock breather screws to put in the banjos, I saw that the stock screws each had a small hole where the hot air exits. I measured the stock hole size and then I drilled the hole in my clear hose to be twice the size of the stock hole.

 

I sort of like what you did.

You should have no gas smell coming out of that hole.

But, it is possible that you are smelling gas from your intake and not the breather tube...they are very close.

If a gas smell is coming from the actual breather hose, you are either too rich and gas is making it's way past the rings in the the bottom end, and then coming out the breathers, or your rings are worn and letting gas past.

If it is running well I would not worry about the rings. If you want to satisfy your curiosity, a leak down test will let you know if there is an issue.

 

Thank you Kevin!

I can also use the long black hose you provided (in an earlier kit I got) and route it down towards the road. But even then, if I stick my nose at the end of the hose, I can smell the gasoline. The smell is only apparent when the engine has run for a while. Like 20 or so mins.
Is a leak down test the same as the "compression test" that John referred to above?