84' carbs on 86' vf500f engine

Hey, i have an 84' 500cc interceptor that has a bad top end. I was hoping to transplant the 84' carbs onto a very clean 86' engine that came with a nice matching frame and some other bits.

Is this swap possible? What other problems might come up when transplanting 84' fairings, radiator, thermostat housing, calipers, seat and, tank? I have most of the 86 stock suspension and electrical parts. Minus the clip ons and rearsets.

the previous owner didn't mention that the rear cam chain tensioner was no good, the guide was pressed down to keep the chain tight


before a "valve check"

rare metzeler chin spoiler?

 

The carb specs on the '86 are different. I believe that they a 2 mm smaller. Also, on the '86, they did away with the fuel pump. Much of the body work is interchangeable, but you have to be careful with the carbs, electrical and mechanical stuff. Even though the '86 looked the same as the '84 and '85, it had a lot of changes to it.

 

They will fit just fine. In fact, they will produce a couple more hp on the 86 engine than the original carbs did. This is one of the easiest ways to make more power on the 86's!

 

What exactly goes wrong on those chain tensioners? Is there any way to make them work?

 

That's a really long story. Honda made some updated designs but everything is discontinued now so it's moot. I wouldn't worry about it on the 500's, dropped valves are by FAR the biggest issue with those engines.

 

Jamie - would this be a straight bolt on? The throttle bore on the '84/'85 is 2 mm larger than the '86. Would he need to use the carb bands from the '84 or will the ones from the '86 fit? Also, are there any differences as far as the cylinder intake goes? I almost tried this before, but was not sure whether it could go straight on.

 

Yeah, it basically is. The 84-85 insulators are a different part number than teth 86's but I can't remember if they are necessary or not. The throttle bore is larger on the earlier carbs but the OD of teh spigout might be the same. I think you need to use the 84-85 base plate and maybe even the airbox too, so just to be safe it's a good idea to get all of those parts.

 

Good to hear! I have all the 84' parts which are in decent condition. It probably wouldn't be a bad idea to buy some new intake boots, should i look for the 84-85 boots.

Whats the story on the pump, will i need to use the fuel pump from the 84?

I am i bit concerned about the wiring loom, i only have the 84 loom.

thanks

 

Not a bad idea at all. Yes, I'd go with the 84-85 parts just to be safe.

The 84's don't need the pump from the 84. Gravity feed works perfect on all early VF's, the pumps were just a CYA until Honda could prove it was ok to eliminate them. That's why they went away in 86 and didn't come back until the ram air intakes started showing up in the late 90's.

 

Are there any recommended carb rebuild kits out there?

It would be great to do the CBR rear shock mod but, now i have two stock shocks.

 

For 500's? I've been selling a kit for $20 that includes just the basic seals. I don't know of anyone else offering one, not even K&L.

Honestly, that just means you probably have two bad stock shocks. I've seen that all too often, people buy a used shock only to find out that it's just as bad or worse than what they had already. Those shocks are just beyond their expiration date I'm afraid.

 

dclassb - keep us up to date on the progress with the carb swap and what was actually involved to make it happen. It will be a big help for all VF500F owners.

 

Actually, this trick has been used for a long time by VF500 guys. There's really nothing to it. Don't expect the little 500 to be a rocket afterwards, but dollar for dollar (considering the cost for used carbs) it's a pretty cheap way to make a hp or two.

 

i just put a set of '85 carbs on an '86 motor and I had to use the 85 carb boots. It was alot tougher getting them to fit than it was on my 85 motor but they still fit. I havent fired it up yet but I dont see why it wouldnt work

 

My Dad and I made a four tube manometer and tested it on a v30 Magna but other than that I have not worked on the bike. The store I work at is closing in a couple months so that should give me the weekends to drive to my Dads.

I know, excuses, excuses.

 

Thanks Pcohen for the post on this - it's exactly what I am doing at the moment. I have an 85 that the clutch rod bent when the chain snapped and so I had an 86 engine sitting there so I just swapped the motors and kept the 85's carbs on. I am curious how it turned out for you like if there was anything in particular that you had to do because I am getting what really just sounds like popcorn when I am around half throttle or greatter regardless of what gear I am in. I've gone over the carbs multiple times but could still be missing something....Any help would be greatly appreciated.