Mounting MikesXS Reed Valve on Late Special Breathers

[aldo5468]

I bought a reed valve like MikesXS #15-0677 cheaply on eBay over year ago and had it mounted on the breather outlet of my '82SJ with the shortest piece of 1/2" hose that would hold it on. It sat crosswise, so wouldn't drain any oil that might come through the breather, and I didn't like how it looked, so I wanted to attach it vertically right on the breather outlet and closer to the breather.

Unlike the earlier breather design with the outlet centered on the rear face, the later-style, "shallow" breather has its outlet near the top, and when you try to align the valve body inlet to it with the valve positioned vertically, there is interference between the top of the valve body and the rear of the top engine mounting bracket (see "Frame Interfere" pic). The following mod's were needed to complete the installation:

Mod's to Valve Body -
1) Remove mounting bracket from valve
2) Remove steel inlet tube (tap out from inside the cover with appropriate-size drift)
3) Shorten steel outlet tube (optional) (see pic "Modified Breather_2")
4) Relieve top edge of valve body (see pic's "Area to Relieve" & " "Clearanced Breather Body")

Mod's to Breather
1) Shorten outlet to edge of outer barb (see pic "Modified Breather_2")
2) Drill outlet to constant internal diameter
3) Sand barbs down slightly for a tight slip fit into valve inlet
4) Enlarge the small hole in the steel baffle plate
5) Add 2 holes to the short rib on back side of baffle

Mod to Frame
1) Remove rear 1/4" of engine mounting bracket (see pic's "Material to Remove" & "Frame Interfere_1")

Assembly
1) Replace allen head screws with 6mm x 1.0 - 30mm hex head screws
2) Place all 4 hex head screws in breather body BEFORE attaching valve to breather (these become captured, except maybe for the lower left one) (see pic "Breather & Valve As'sy" - pic only shows 2 screws in top holes, but do all 4)
3) JB weld the valve body to the breather outlet - valve inlet should align with the inside barb on the breather discharge) - let dry
4) Install on motor (see pic's "Breather Valve Installed_1" & "Breather Valve Installed-2")
5) Install drain hose from stock system or other 1/2" hose

 

[No_Harley_Here]

Wow, that looks great. I like the detailed pictures

 

[thelowlife]

Nice write up.

I posted my same install a while back without such detailed photos. Good job!

 

[angus67]

i was wondering how in the world that thing attached! thanks. now i will get one.
btw, are those sr500 carb tops? I ran across a set of those in a junk yard and am still mad at myself for not getting those for my 34's.

 

[DirtyErnie]

...and there is the el-cheapo mod of putting in a brake vacuum booster check valve. I should see if mine still works.

Nice write-up! That reed valve is probably a lot more durable.

E

 

[aldo5468]

Nice write up.

I posted my same install a while back without such detailed photos. Good job!

Your write-up was my inspiration to do this with the later-style breather body.

 

[aldo5468]

i was wondering how in the world that thing attached! thanks. now i will get one.
btw, are those sr500 carb tops? I ran across a set of those in a junk yard and am still mad at myself for not getting those for my 34's.

Bought these alloy carb tops as a set of four on eBay awhile back - I don't know what bike they are from.

 

[sseres]

does the valve work if I mounted it more downstream from the engine, say right before where it tees off into the two hoses that go into each airbox?

 

[XSLeo]

With a stock air box with the breather plumbed into it the reed valve isn't needed. The air flow over the ends of the tubes the hoses hook to in the air box create a vacumm in the crank case.
Leo

 

[sseres]

rats. Ok. I was hoping it was some kind of magic fix for little leaky spots.