Hot weather fuel problem

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Happy Rider

Well-known member
Joined
Sep 1, 2009
Messages
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Location
Sonora, CA
I have a 2009 FJR and had it parked in Las Vegas. The temp. was 106F and the tank was 1/4 full. The engine was cold, well at least 106F. I started the bike and let it warm up to one bar. When I took off and tried to accelerate it had no power and felt like it was running out of gas. I stopped and opened the gas cap and a large amount of pressure was released. It ran fine after that. This has happened 3 times now and only happens when its very hot outside. Is this normal?

 
There is a pressure release in the fill cap connected to a hose that exits the bottom of the bike. If the hose is pinched it won't release pressure, you might try blowing some compressed air through it to see - look for an orange rubber o-ring under the fill cap to put your air fitting to.

 
+1 Maybe one of the times you were under the tank you pinched the overflow vent line; check your rubber tube routing.

 
No, it's not normal. Get it fixed or when you're in the opposite situation, as in the temperature drops creating a vacuum, the tank could collapse in. Happened to me on another bike.

 
Thanks for the tips. I'll check under the tank. I did have it up to run some wires so maybe I did pinch the line. The Yamaha shop in Kingman, AZ said it was normal. I thought he was trying to brush me off.

 
Does it self correct after a minute or so (3 -4 bars on the temp meter)? It may be the auto choke that's in the game as well. I've done a warm engine start after waiting 1/2 hour post shut down that causes the auto choke to engage & the bike rides like a pig for a minute or so.

W2

 
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I had this happen on my 08 a couple times last year, and thought it was a vapor lock problem. In my case it would clear up after a short distance.

I just realized when I read your post that I haven't had it happen this year. I don't know if your fuel formulations in Nevada are similar to ours here in Ca., but we don't have the most stable fuel when it comes to vapor lock. I don't know if fuel formulations are different this year, but it wouldn't suprise me if they changed.

I'm sure my Ca. model has a vapor recovery system on it so the venting issue wouldn't apply. One of the things I was going to try if it were still an issue this year would be to run premium fuel hoping that it would be less prone to vapor lock.

Keep us posted, I'd like to know how this turns out.

 
It happened to me too when I was on my way from Las Vegas to St. George a couple of years ago. Two up riding in 106+ temp, full load, uphill. When I stopped the tank was too hot to touch. After fueling up and a little cool down time, the sputtering problem went away. Since then I installed Smitty's (?) under tank heat insulation blanket, and the issue has not come up yet - even though we rode through 114+ heat in Arizona under the same load last year.

Silverbear

 
If you need a great shop in the kingman area drive 70 mile west to Lake Havasu. Walts Kawi and Yamaha. My son works thier and I have none the owners for 25 years. They will repair it right.That problem is not normal. I have delt with that shop in kingman they are HD dudes. Need I explain more. Hope this helps you.

 
Thanks again for all the info. I just looked under the tank and I don't see any issues with the vent lines. It is a California model so it does have the vapor recovery system. The problem did self correct the first time after about the third temp bar. I looked under the filler cap and saw the orange hole for the tank vent. Looking at the gas cap it has a round gasket that seals the tank hole. The orange vent hole is outside the round gasket so it does not look like it would have anything to do with pressure building in the tank. I tried to blow some air down the orange vent hole and there was quite a bit of resistance. It lookes like the vent goes over to the recovery canister. It looks like there might be a one way saftey valve as the vent line leaves the tank on its way to the canister. I wonder if the one way valve may be backwards. I'm back in Sonora, CA again. I'll bring it by the local Yamaha shop on Tuesday and see what they think. They will probably tell me to pound sand since it will be difficult to duplicate. So far I haven't had much luck with this shop. Anyone know of a good one in the Sonora area if I don't have any luck?

I've ridden about 2400 miles in the last 4 days, in Colorado, Utah, Nevada, and California, in temps from 40 to 95 F and altitude of 2500 to 11000 feet and it hasn't happened again. :huh:

 
I'll bring it by the local Yamaha shop on Tuesday and see what they think. They will probably tell me to pound sand since it will be difficult to duplicate. So far I haven't had much luck with this shop. Anyone know of a good one in the Sonora area if I don't have any luck?
I've ridden about 2400 miles in the last 4 days, in Colorado, Utah, Nevada, and California, in temps from 40 to 95 F and altitude of 2500 to 11000 feet and it hasn't happened again. :huh:
Former Larry Bird shop? I believe I'd call Modesto Yamaha. Once upon a time, the service manager owned an FJR...I don't know it he's still there.

If you're willing to travel: Roseville Yamaha in Roseville CA (East of Sacramento).

 
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Lots of California bikes share the trait (stuttering when starting after sitting in heat). Here's a link to an explanation and fix I haven't personally attempted.
https://www.fjrforum.com/forum//index.php?s...3&hl=alaska
Thanks for that.

Thinking more about it, I probably didn't have the bike parked in the same high heat conditions this year, so that's why I didn't have the problem this summer.

I don't doubt it's a canister issue but it sure didn't seem like it was a too rich loading up issue. It seemed like lean, vapor lock.

I wonder if the pressure created by the hot fuel vaporizing somehow overcomes the injection system causing the bike to try to run on vapor till it clears.

I had the canister off one of my Ninja's and I always smelled like fuel vapors after I rode that bike, so I left the canisters hooked up on my last 2 bikes.

If the canister causes the power loss problem, it may need to be disconnected for safety issues :devil:

 
Does it self correct after a minute or so (3 -4 bars on the temp meter)? It may be the auto choke that's in the game as well. I've done a warm engine start after waiting 1/2 hour post shut down that causes the auto choke to engage & the bike rides like a pig for a minute or so.
W2
+ 1
Don't know so much about that + 1, since the FJR really doesn't have an "autochoke". It IS a auto-temperature controlled system, but it's really only an air bypass system. It allows more air into the intake tract during cold startups, kinda like just twisting the manual idle adjust screw in farther. It doesn't "choke" down the intake, in the same context a true choke does. It doesn't increase the fuel flow, like a carb enrichment circuit does. It just opens up an air bypass valve on each throttle body to allow more air into the intake. The ECU DOES increase fuel enrichment when the coolant temp is low, below 140 degrees if I recall, but that shouldn't be the case since everyone describing the issue attributes the problem on a HOT re-start.

I'd be more likely to blame the vapor canister system, dumping huge amounts of fuel vapor into the intake, causing the bike to go WAY rich, which the O2 sensor will detect as a drop in oxygen, telling the ECU to lean the mixture on a notoriously over-lean system to begin with, and Bingo....bad running FJR.

I'd guess you really only have to choices.....live with it and cuss CARB everyday, or go full-tilt iconoclast and yank that sh*t off!

 
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I'd be more likely to blame the vapor canister system, dumping huge amounts of fuel vapor into the intake, causing the bike to go WAY rich, which the O2 sensor will detect as a drop in oxygen, telling the ECU to lean the mixture on a notoriously over-lean system to begin with, and Bingo....bad running FJR.
Aha, that makes sense. The bike definitely seems fuel starved when this happens.

 
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