Hot day, possible vapor lock, bogging then jumping forward

[Susan]

I had a scare yesterday, and I think it was from a vapor lock. It was idling at a needle width over 1K (that's where it always has idled).

It happened several times, like this:

1. Bike was sitting for a while in the heat (it was hot out, between 90 and 100 degrees).
2. It didn't start on the first try, but it started on the second try.
3. When I went to take off, it acted exactly like it was in 2nd gear, bogging down in that awful nearly-stalling way (but it was definitely in 1st).
4. I pulled in the clutch lever then let it out the regular way and gave it more throttle.
5. The bike suddenly leaped forward as though I'd given it a lot of throttle and let out the clutch way too fast.

It didn't happen every time I took off, just shortly after it'd been sitting for a while. Not very fun when you're pulling out of a parking lot and turning onto the street in traffic. :spank:

The bike is properly maintained and not abused. It's just about time for an oil change. And I have only 12K km on it. No mods other than a lowering link. So I hope it's just weather related.

I'm going to check the fuel line and vent(s?) today. Other than that, do you have thoughts on what could cause the bogging and then sudden leaping?

 

[FinalImpact]

Not sure what your night temperature are but if the temps are swinging drastically, water may be condensing in the tank. When you stop, condensed water can separate and that could cause this as the bike was not able to burn the liquid injected.

Fuel injection is not noted for vapor lock. Try adding the proper amount of gas dryer for a 4.5 gallon fill.

Even a heat soaked fuel tank with plugged vents is not going to build more pressure than the system runs on so its not likely. Gas Quality is a greater potential issue IMO.

 

[Susan]

Not sure what your night temperature are

About 60 or 65, usually.

Gas Quality is a greater potential issue IMO.

Ohhhhh. Hmmm. We usually use non-ethanol fuel, but when we filled up yesterday, shortly before the issues started, our only option was "up to 10% ethanol" (Chevron, shame on you).

But. I just remembered this: A few days ago, after about an hour of riding at 60 mph with no issues, I slowed to 40 for about half a mile and then turned up a side road. Exact same thing happened at that corner. Bog, clutch, gas, zoom, eek! I was alarmed and thought it was just me riding with my brain disengaged. But surely I can't be doing that this consistently. And it was only around 75 degrees that day.

 

[FinalImpact]

About 60 or 65, usually.



Ohhhhh. Hmmm. We usually use non-ethanol fuel, but when we filled up yesterday, shortly before the issues started, our only option was "up to 10% ethanol" (Chevron, shame on you).

But. I just remembered this: A few days ago, after about an hour of riding at 60 mph with no issues, I slowed to 40 for about half a mile and then turned up a side road. Exact same thing happened at that corner. Bog, clutch, gas, zoom, eek! I was alarmed and thought it was just me riding with my brain disengaged. But surely I can't be doing that this consistently. And it was only around 75 degrees that day.

Even with the potential maybe of Chevron gas being an issue they have a product called Techron (w/techrolene, in a black bottle) which is great product for cleaning the fuel system. I run it in everything usually 4 times a year 2 of those being just before freezing temps set in. I'd run a bottle (treat for 5 gal) and see what happens.

Any other drive/ride-ability complaints? Isn't this a bike that was sitting for a long time? And what all was done to it, how many miles, has it ever had new plugs installed?

 

[Susan]

Dh agrees a fuel treatment and the spark plugs (I'm still on the original plugs) are the next things to try.

Of course, things looked good yesterday evening and I took her for a ride, and she didn't misbehave at all. It was a little cooler out, in the eighties.

This bike was sitting for a couple of months right before I got it (three years ago). Maybe you're thinking of my poor old Nighthawk that was sitting for years and years. The FZ6 sits during the winter, of course, in a heated shop and with Seafoam in the tank. It's been on the road this year since sometime in May.

No behavior complaints until now.

We haven't done anything to it beyond keeping the oil changed, the chain lubed and adjusted, new tires, lowering link, and flushing the antifreeze (it had that weird black antifreeze that looked like cola). Regular maintenance things. But it is time for new plugs.

 

[Randomchaos]

I had my Buell vaporlock on me once in 105 degree weather after sitting in traffic for awhile. Got to my destination, shut bike off, came back out 5 minutes later, would not start and run. Would fire over then die after a second. Once it cooled for awhile, everything was back to normal.

Your problem does not sound like vapor lock, but maybe clogged injectors, or possibly some crud floating around in your tank, or even just a run of bad gas.

 

[TownsendsFJR1300]

I think I'd run that tank on a heavy dose of Seafoam, could of very well picked up some moisture, settled on the bottom and now the injectors are pumping it..

BTW, you didn't notice the gas station getting its tanks filled while you were filling up did you? I ask as when there being filled, it stirs up all the crap in the bottom of their tanks, you in turn(if at the same time) pump that crap into your machine...

Just an FYI, IF, you have an on going problem with water intrusion, I found this product (I use mostly in the boat but in the bike occasionally), K100. It mixes with any water/fuel into one mix, it STOPS SEPARATION. You still have water in the tank but now instead of being in the bottom of your tank, its being burned off with the fuel. I l know it works as I've personally used it in my boat the last 1.5 years or so (built in 50 gallon tank). The fuel was milky looking before, water droplets would also form.

Now between using Non-Ethonol fuel and K100, absolutly NO droplets, fuel looks brand new (and smells fresh). It also stabilizes fuel too:

K100 Fuel Treatment (K100MG)

 

[Susan]

I didn't notice a gas truck, though there could've been one there earlier. Dh's bike wasn't acting up, though, just mine.

Oddly, the problem has improved somewhat without a gas additive. Lately I've been running around like mad, ferrying my kids in the minivan, and stopping in at Lordco has been the last thing on my mind; but after a few more tanks of good old Canadian gas, maybe whatever got in there has run its course.

However, I noticed something else. The idle is down just below 1K. I know, I know, someone asked if anything else was weird, and I didn't notice the idle speed until just now. :spank: Now to find the time between offspring-related errands to change my plugs and sync the throttle bodies and adjust the idle.

 

[Susan]

I'm so impressed by myself! I managed to change my spark plugs with minimal supervision, no swearing or crying either. :cheer: They were pretty worn out. But the color was nice.

I didn't have time to get to the throttle bodies bodies (hopefully tomorrow), but dh pulled out his clever little idle speed measuring tool, and I got my idle adjusted. Well, at least until I start in on the throttle bodies....

 

[TownsendsFJR1300]

I'm so impressed by myself! I managed to change my spark plugs with minimal supervision, no swearing or crying either. :cheer: They were pretty worn out. But the color was nice.

I didn't have time to get to the throttle bodies bodies (hopefully tomorrow), but dh pulled out his clever little idle speed measuring tool, and I got my idle adjusted. Well, at least until I start in on the throttle bodies....

A 20 minute job, now, that you've done it and know the secrets/tools required!!! Great job.


Re the sync, I'd strongly suggest, besides syncing at idle, re-check and adjust at 4k RPM's (a steady 4k, some revving inbetween adjustments and a large fan in front of the radiator / header).

The #4 cylinder will likely pull higher vacuum. Getting them in line at 4k, helps a bunch with eliminating any buzz. You should find, at idle, the sync will still be within 2-4mm's and at 4k.

Please post how it goes!

 

[Susan]

Yep, there's a huge stickied post I've been studying (the one about building a manometer). The fan is a good idea. Thanks. And dh concurs.