Can a wind gust cause instant vapor lock?

ed85379 · Post by **ed85379** » Fri Mar 09, 2012 12:22 am

Like the subject says, I was wondering, can really strong winds cause vapor lock?

Now, I've had vapor lock in the past, but I'm in the habit of always popping my gas cap before riding, and since I started doing that, it has not happened again.

So tonight I was leaving work, and as usual, popped the gas cap. Then started a quick 1.5 mile ride to the nearby scooter shop. I was going to try on some warmer weather gloves. Well, on the way there, I lost power and stalled *twice* in that short distance. The first time it completely stalled, and it wouldn't start again until I popped the cap.

Now, the winds are *extremely* strong tonight, and during that trip I felt some of the strongest winds I've ever felt while riding. They were pretty scary actually.

So while I was at the scooter shop, they donated a vented gas cap to me, and the ride home was perfectly fine, with no stalls at all. I didn't encounter winds nearly as strong during the 9 mile ride home either.

skully93 · Post by **skully93** » Fri Mar 09, 2012 12:56 am

wow! can't say that's ever happened to me!

Glad you didn't blow over.

viney266 · Post by **viney266** » Fri Mar 09, 2012 3:21 am

talled while riding? Or sitting at a light?

ed85379 · Post by **ed85379** » Fri Mar 09, 2012 3:26 am

viney266 wrote:talled while riding? Or sitting at a light?

While riding.

smithrw · Post by **smithrw** » Fri Mar 09, 2012 11:20 am

Mine had the vapor lock problem as well. Finally put an end to that with a small hole in the cap.

Chilly · Post by **Chilly** » Fri Mar 09, 2012 12:57 pm

I'm going to say yes. Vapor lock stalls happen when giving gas, you gave gas because you hit a wall of wind. So wind caused stall. Sort of.

PeteH · Post by **PeteH** » Fri Mar 09, 2012 1:22 pm

I'm going to say no. Vapor (or more accurately Vacuum) Lock comes about from a closed fuel system with no air venting path to the outside world. No gust of wind is going to blow into the fuel system, and even if it did through the charcoal canister or whatever, it woudl be an overpressure, not an underpressure.

ilektron · Post by **ilektron** » Fri Mar 09, 2012 3:59 pm

A fast moving body of air over an opening actually can produce a low pressure in the opening,

Were these headwinds? Was it possible that the wind gusts put a huge load on the motor causing it to suck more gas and vapor lock?

ed85379 · Post by **ed85379** » Fri Mar 09, 2012 4:37 pm

ilektron wrote:A fast moving body of air over an opening actually can produce a low pressure in the opening,

Were these headwinds? Was it possible that the wind gusts put a huge load on the motor causing it to suck more gas and vapor lock?

Yes, major headwinds as well as huge gusts from the side.

Stormswift · Post by **Stormswift** » Sat Mar 10, 2012 12:36 am

Is there specific time of the year when scooters are more prone to having vapor locks? Seems like a lot of those happen in the spring? Could winter gasoline be causing those vapor locks?

Syd · Post by **Syd** » Sat Mar 10, 2012 12:43 am

Just curious. How strong was the wind the other night? (Steady and / or gusts.)

ed85379 · Post by **ed85379** » Sat Mar 10, 2012 12:44 am

Syd wrote:Just curious. How strong was the wind the other night? (Steady and / or gusts.)

Steady was around 25mph. Gusts... not entirely sure, but I'd guess 50mph.

Syd · Post by **Syd** » Sat Mar 10, 2012 12:49 am

ed85379 wrote:
Syd wrote:Just curious. How strong was the wind the other night? (Steady and / or gusts.)
Steady was around 25mph. Gusts... not entirely sure, but I'd guess 50mph.

Then I'd venture to say that other Buddy riders have ridden in that kind of weather without ill effects. But you never know, you know?

ed85379 · Post by **ed85379** » Sat Mar 10, 2012 12:51 am

Syd wrote:
ed85379 wrote:
Syd wrote:Just curious. How strong was the wind the other night? (Steady and / or gusts.)
Steady was around 25mph. Gusts... not entirely sure, but I'd guess 50mph.
Then I'd venture to say that other Buddy riders have ridden in that kind of weather without ill effects. But you never know, you know?

Well, the other thing to consider is that I was riding downtown, and the winds whipping between buildings can be significantly higher speed. All I know is that when it hit me from the side, I was almost pushed into the parked cars, and when it started coming from the front, I had to give it a lot of gas to not be actually stopped by it. How fast that adds up to, I don't know.

siobhan · Post by **siobhan** » Sat Mar 10, 2012 1:31 am

I rode yesterday and the wind was brutal. But I took the DRZ because it was 63 FREAKING DEGREES in early March in New England, with the thinking that I'd go for a ride at lunchtime. Not to be as it was crazy windy. Grip-the-tank-and-achy-thighs windy. So, yeah, I can't help. It wasn't raining so we can rule out water.

I will say I've ridden in ridiculous wind and not had the engine just die, including over bridges and in tropical storms ('cos, well, it's fun).

It's probably just a weirdness. I've had a few "loss of power" episodes (twist and no power, just coast to the side of road, but doesn't stall) and never figured out what the problem was. I never was able to track it to weather or temperature. I consider it just "weirdness".

ed, I know it's uncomfortable because you wonder, "If I take this corner quick, will I have acceleration?" My Franz has been ok.