VF500F Air Cleaner Base Question

Hello, everyone! Longtime lurker (and learner), first-time poster.

I picked up my dream 1985 VF500F Interceptor a couple of years ago, and am now starting to go through the carbs. After taking off the airbox and the metal screen underneath, we discovered that a previous owner likely tried to pry the air cleaner base plate/carb assembly out using the cross brace, and managed to break an entire chunk off that base plate.

So my question is, I know that the carbs Honda supplied on all years of the VF500F in the US were all different. But are any of the air cleaner base plates the same? I haven't found a good answer searching, so I thought I'd ask. Thanks for both your help and your patience!

 

Are you talking about the aluminum plenum?

 

This piece if that's what you mean. The parts diagram calls it the air cleaner base.

 

Ok. Pretty damn sure 84 and 85 are the same piece, or at least casting.

See that raised ridge in the center? On 84, the carbs are vented to the air box through that area. On 85 it is plugged, as those carbs are vented to atmosphere. Venting to air box changes the jet size requirements dramatically.

What I can't remember, but can verify, is if it is simply plugged or just not machined on the 85.

Perhaps you can tell too.

 

OK, interesting! Thank you for that. While the bike I have is an '85, so far I've only removed the carbs from the bike and haven't started to take them apart yet. That should come later today, and then hopefully I'll know whether the carbs are truly '85, or sourced from an '84, or what.

I'll report back later today or tomorrow, after I take a better look at it. Can probably get some better close-up photos of that ridge, too.

 

The good news is that you can find some less than stellar carbs (cheaper) to source that piece from and perhaps pick up some spare parts in the process.

It will either have a pass thru and the carb vents attached to it (84) or not (85).

 

There's a couple different angles of close-up views of that ridge. There are those cut-outs in the two ribs on either side of the ridge. The hole in the center appears to be plugged and air doesn't go through.

 

align and stabilize the piece with tape on the inside, then use epoxy on the outside. after its dry remove tape and coat inside with more epoxy JB weld.

 

85.

84 the hole is actually a threaded fastener hole for a baffle plate (pretty damn sure). I will get both year carbs out later and show you.

So you could use an 84 base, just need to JB Weld or silicone fill any passages.

 

Awesome, that's great news. Thanks! I didn't have a lot of time to get deep in last night, but I'll be plugging away as I can. Really appreciate the guidance.

One more question (so far): In that first photo I posted, there's a noticeable amount of oil over carb #1. Is that normal, or should I be concerned?

 

Thanks for the suggestion, but there's stuff that's a bit bent where whoever it is went at this thing with a pry bar. So it's also not totally straight at that corner, and I'll likely go the replacement route since it's not super expensive/unobtainium.

 

You can / will get some oil in the airbox as it is connected to the crankcase breather plumbing. Almost every carb plenum I get into has some. What I see is not something to be overly concerned about, just monitor it after you get it up an running.