heated air diaphram to aircleaner

[Thomas Dick]

I was going to replace my air filter today and found the diaphram to the carb heater missing a vacuum hose. I have looked all over the place, tried to find the hose to the diaphram on the hose routing guide and to no avail. I assume that the hose comes from a ported switch somewhere to allow the valve to be shut off when the engine gets to a certain temp. Can someone guide me in the right direction?

[gipsy42]

Hi Thomas:
The hose you’re looking for goes conected at the left/bottom of the air cleaner housing; when you remove the filter, will see inside of housing a sort of bimetallic that actuates with temperature closing a vacuum valve, and from there to the diaphragm.
Kind regards, Mario

[ct1500]

The temp switch is located in and under the air box on the left side. You will have to lift the air box up to look underneath for the hose. It should be pink in color with a vacuum check valve inline.

[Thomas Dick]

Ok, I found a vacuum hose coming directly from the intake manifold with a pink ring around it that went only to the bimetalic valve inside the air cleaner box. Is there supposed to be a tee in that line (not there) that goes to the diaphram? I tested the valve and I can see that it would open up when warm and allow a vac leak so it only makes sence that it would allow the diaphram to open when closed and close when the spring opens the valve. Is it possible that this could have been this way since new and the diaphram not hooked up? Oh by the way thank you in advance for everyones help.

[ct1500]

Unless you owned the bike since new the likely scenario is someone was in there previously and harvested it for use elsewhere or simply left it out for whatever reason.

[Thomas Dick]

That explains everything, thanks so much..