What happens if you run an EFI bike without a filler cap? Would it do permanent damage to the engine?

 

I bought a spare cap from the HD dealer. I keep it in the saddle bag. About $15 each.

 

If you lose it? Buy a new one. Wash the jeans if you got gas on 'em. The bike will be just fine.

 

Good idea - think I'll do the same!

Still curious what would happen to the motor if you didn't have a spare...

 

Speaking from first hand personal experience,... no.

Last year I was on a cross country ride. We stayed in Show-Low AZ and one morning I forgot my gas cap at the Shell station across from the hotel when filling up. I rode all day without a problem. I did smell gas fumes and but assumed it to be spillage from a previous overfill. I discovered the cap was missing when we stopped to fill up. I filled the tank most of the way but left it a bit lower than usual. When I got back to the Shell station the attendant had it waiting for me inside. I filled up, put the cap on and that was it.

Well not quite. Now every time we stop for gas James busts my chops by asking, "Didja remember your gas cap?"

 

i can not see any reason for the engine to get damaged but like the newer cars the check engine light might come on to let you know there is an emissions problem.

 

how do you loose a gas cap on a MC? i would have gas all over me before i got out of the lot, id remember that dang thing right away.

 

It's easy to forget one on a touring bike, I've done it myself as many people have. You won't hurt your engine, it's not a big deal. As stated above, I now carry an extra one in my saddlebags. And an extra lighter too, don't ask me how I know!

 

Next time you leave it take off one of ya socks and stuff it in the hole, gas is too expensive to let it spill out or evaporate. And no it will not damage your engine, leavin the cap off that is, the sock wont either.

 

It won't hurt the motor at all... Now, you can get a replacement cap at any auto parts for about $5-6 bucks my Dodge truck cap works on my bike. or you can spend $12 at the dealer for the one that has the bar & shield on it. Most gas stations have a collection of caps right behind the counter that poor souls like yourself have left behind. Ask for one, they will give it to you in most cases. I don't believe all caps are the same thread, but most are.