89 GL1500 Gas cap

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There's no vent line on the cap ...



Here's a foto of some other stuff (cap near center bottom) no hose or vent or anything -- the plastic perimeter piece is just a lanyard to keep the cap from wandering off during fills.

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Damn... My bad.

Is your bike originally a California Emissions model?

The "all others" cap (HONDA 17670-MN5-003) is what that photo shows...

I've not worked on a CA model, but they have the hose you're speaking of (cap = Honda 17670-MN5-741).

Be prepared for the sting, that cap is prolly 3 or 4 times the price of the standard cap.

Goes to show, I sohoulda looked it up before popping-off the quick answer (does your air filter have the embedded charcoal element?)

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To identify the emissions package on the bike there are a couple of 'flags' and one dead giveaway.


- The fuel cap with a hose is part of an extended evaporative emissions control system not (generally) found on the 49-state bikes.
- There will be a vacuum hose routing diagram on the fuel tank (lthat'd be under the front of the seat) for CA models (I've seen a few of the diagrams, but I believe that they're for CA only in 88-89)
- There is an additional charcoal element that is screwed into the air filter taking roughly 1/4 of the available filter space (left rear corner area of the filter is where the charcoal element is fastened) - usually NOT installed if someone priced the CA-only air filters:shock:
- The Dead-Giveaway would be to look at the emissions label (a "Vehicle Emissions Control Information Label" is required for all US models) that'll be affixed to the right side of the frame usually at the front edge of the space covered by the battery cover. The label would indicate if the bike was certified to the US emissions or to California emissions

If it all comes down to being unknown still, you could have a dealer run your VIN, Frame, or Engine's number (VIN probably best) to see what market it was built for.



If memory serves me correctly, the CA models also have a carbon canister that is plumbed to collect these evaporative emissions as in - line to the fuel cap, line to that funny metal pipe (the cab float bowl vents) and probably one to the air filter box. The intent of that canister is to use a weak vacuum in the canister to "draw" HC emissions from the connected systems into the carbon media in the canister, then on the bike's next start allow the stored HC vapors to be drawn into the engine's intake for combustion/conversion into some other pollutant (heat, noise, power, etc)



As for leaving the hoses disconnected being a "trouble" for the bike... I don't believe that it would have major impacts, HOWEVER... The calibration of the computer and jetting should address the flow of gasses that will be entering from the evaporative canister (ok really ought'a, but I have none of the running code for the computers or specs on CA-specific carb changes). I'd suspect that on the grand scheme of things, I'd suspect that as long as you do not un-cap any vacuum source you'd be OK (the canister 'prolly has a temperature or vacuum-level sensitive control on however it's routed back to the intakes)...



That said, I'm blaming the disappearing polar ice shelf on you two guys :cooldevil: