I'm sucking air! 86VF500F

Just finished rebuilding my carbs and reinstalled them onto the bike with new boots (re-uesed old clamps). The bike won't start without using starter fluid. Once it starts it will run above 3k but if it drops below that it will die. I've confimed I've got an air leak around some of the boots. What I'm thinking is that I either have the wrong boots or the wrong clamps because when the clamp is full tight (clamp is bottomed out with no more adjustment) on the boot I can still turn the boot. The Honda part number on the boot package is correct for an 86 and they were sealed. I think there were some changes on intake size between the years? I'm trying to confirm that. Also, I trying to confirm my engine is an 86. Engine number is PC12E-2205941. I'm thinking maybe I have the wrong clamps?

 

you need to make sure the boots are on correctly... there are a little spots on them that need to be in the right position... that and you can put them on backwards... don't ask why it seems weird but that could be your problem...

the clamps could also be worn out.....

 

Yeah, Iprobably should have mentioned that. They say "carb sid" on them and there's an arrow that points up. I've got them all properly installed.

 

The '84s and '85s had 32mm carbs , the '86s 30mm carbs. I would think that the insulators would have different inside diameters. Is it possible that you have '84/'85 insulators ? I looked up the part #s, they are different. The insulator part # for the '84/'85 is 16211-MJ8-000, the # for the '86 is 16211-MF2-711. I recently sold my incomplete set of '85 carbs, so I cannot measure the OD of the carb horns. The OD of the '86 carb horns is 35mm, maybe someone has an '84/'85 carb body and can check the OD of the carb horn to see if they are indeed different.

 

The boots had the correct part number on the bag. My guess is that I may have the wrong clamps. The part number for the 86 clamps is different from the 84 / 85's.

 

New boots should seal well enough on there own to prevent such a leak. You may want to remove and carefully inspect the boots and sealing surfaces. The boots are directional and are marked for top and bottom.

 

Anybody know what these holes do (circled in red)? I assume they are probably in the casting and then closed up afterwards? The two outside carbs are the ones I'm getting the leaks at and those carbs have two additional holes in them like the one on the right in the photo. If I spray the starting fluid around the boots in those locations I get the engine rev. What do you think? Do those lead to internal passages? The ones that are blocked off with the brass plug are the mixture screws.

 

Some clamps have an small spacer between the two sides that limits tightening, and if you remove it, you might get what you need,

 

I have a set of '84 carbs that I just measured and the ID is 32 mm and OD is 38 mm.