I'm putting together the RR conversion bike and ran into a problem that I can't quite figure out. This is very weird, at least to me.


The engine is out of a 1987 Hurricane. On the front under the exhaust it has an oil line galley with some sort of vacuum system. I think it is breather related because the pipe go into the top of the valve train. There are hoses that I can't figure out where they go. I looked in the manual and can't find anything. Can't even find any pictures of this thing anywhere. Here is what I'm talking about.





There is a big gray hose that comes off of it and a small diaphragm that looks like it should have a hose on it.





I took a picture of one of my 1988 Hurricane engines and none of them have it. The galleys aren't even drilled out for the pipes.





Is this something special or did they eliminate it between 87 and 88? Does anyone know where the hoses go?

 

I think I may have figured this out. Hopefully someone can verify this. This engine has California Emissions controls. This is all that is left of it. The system should have an air canister, special carbs with ports, etc. I think I am just going to plug it because I think this is taking air vapor from the engine. I can't take it off because the pipes go to the valve galleys.

 

That's an air suction valve.

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Yeah I know...can I plug the lines. I don't have any of the other parts for the system.

 

I would think so. Vent the crankcase like your other motor and plug the holes.

 

Yes I have all the regular crankcase vent parts. I think the engine was vented that way because none of the parts for the California emissions are there but what I showed in the photo.

 

Your first picture is how my bike came to me when I bought it. Just the valve & hoses/tubes were left over but not hooked up to anything. I believe that system only came on the '87 California spec bike.

I removed the entire assembly and plugged the holes, and have not seen any negative consequences from doing so in the past couple years. I'm sure it can't hurt anything since the emissions system was not functional anyway. As a side benefit, it cleans up the front of the engine nicely as well.

edit: I cut off the ends of the pipes at the flange where they connect to the cylinder head and sealed them, then re-installed them to plug the ports in the head.

 

Thanks so much for the great idea on how to deal with this. I pretty much figured this was California spec and was thinking about making some aluminum plates to close the holes...but your idea is easier and will work just fine.

 

My head I had ported and decked came off a California spec bike. We just tapped the exhaust holes at the head and put in some bolts with thread sealer.

 

Another good idea...thanks.