82MHR breather hose valve

Aussiess · Post by **Aussiess** » Sun Oct 15, 2006 9:25 pm

I have an 82MHR, which was purchased in a very poor and dismantled condition. Finally I am approaching completion, I note that on the "to atmosphere" end of the breather hose from the breather box that there is meant to be a "valve" arrangement. (So the manual says ). Can anyone give me an ideas to where /how to get hold of one or if this is necessary and I just leave the hose open to atmosphere. The engine has received a full top end overhaul and hone/new rings, we shouldnt see too many issues I hope when started.

Post by **BevHevSteve** » Sun Oct 15, 2006 10:52 pm

hey Grant, I use a little K&N air filter designed for an automotive valve cover breather - available everywhere. Originally there was a little metal tube thing with a rubber flapper deal. The air filter will simply keep things from getting in your engine, and, it will keep any oil mist from soiling your bodywork etc. Some folks run the tube out along the rear fender open at the end. I dont; really like the way that looks so I trim the hose so the air filter sits just up under the seat, out of the way and out of view. Very sano way to do it.

DesmoDog · Post by **DesmoDog** » Mon Oct 16, 2006 8:35 am

I'm pretty sure this is the type of filter Steve is talking about (the pinkish colored thing to the right of the carb's filter). This is how I mounted one on a 750 GT, your application would be different. I was a little leary of installing it anywhere other than the high point of the hose, but it fit well here so I tried it out. So far no problems. (BTW - in use it's hidden by the side cover)

Peter Mille · Post by **Peter Mille** » Tue Oct 17, 2006 12:37 pm

That's exactly the way I did it on my MHR Mille, altough I have fitted the KN upright.

Aussiess · Post by **Aussiess** » Sun Oct 22, 2006 3:26 am

Many thanks gents, A sensible approach.
I have spoken to John at mdinaItalia in england, he checked an english 82 model MHR and the hose ran all the way along the frame tube to the front of the engine just before the front of the tank, at this end point it was to atmosphere, no filter.

I think I may combine the filter and the longer tube, see how it sits.

Peter Mille · Post by **Peter Mille** » Sun Oct 22, 2006 6:07 am

Why would you use a longer tube, it makes no sense at all!
The shorter, the better, a longer tube wil allow the gas to cool down, and create a kind of white yoghurt at the end, if you know what I mean...!!

Spub · Post by **Spub** » Mon Oct 23, 2006 1:43 pm

I used a similar air breather filter and attached it in approximately the same position as Desmodog. I was conflicted on where to place it, since if you are not careful on filling the crankcase, any excess oil can be blown out this vent. Last thing you would want to see is oil being spritzed on your rear tire. On the other hand, a shorter vent hose would appear to be more efficient. This filter is widely available, DennisKirk has them on line.