So at one point last December, I noticed that my gas light went on at 68 miles (normally I light up at around 130). Thinking this was a fluke, I filled up and parked the bike, only to have it taken out in its spot. This led to the bike being parked for about a month and a half.
Got it back on the road earlier this month, and this mileage issue is still around. Two more tanks lit up at ~70 miles. As usual, put in ~3.8 gallons to top off. Now something's definitely wrong.
I changed the plugs a few days ago to stock from iridiums (which included lifting the tank and looking around for leaks as someone suggested; nothing) and filled up. Last night the light went on at 48 miles.
It was a pretty sudden drop, so I'm sure it's not the air filter (was changed last summer). Should I be looking at the FPR? The bearings are in good shape.
Can someone suggest something? I've learned the hard way to have a KISS approach to this bike, but my regular mechanic dude is indefinitely MIA and I'm at a bit of a loss.
Is there any possibility of someone stealing gas from your bike or someone just messing with you? If you have that bad of an external leak I would think you would have a pretty heavy gas smell. If the FPR is leaking that bad, it would seem that the bike would really run like crap.
Highly doubt that. I would think if that was the case it wouldn't be as consistent, especially with the downtime in-between (during which it was parked in a garage). Also, the FPR was changed last summer when I was troubleshooting something else and the bike seems to run pretty normally. As for smelling gas, no smell until I spilled some gas on my riding pants when changing the plugs (long story), but I notice that more at home than when on it. :surrender:
googlit is stealing it to get 5.2 gallons in his tank.
I would go back to stock style copper core plugs. And change out the FPR, cus really, the FPR is the ONLY thing on these bikes that would cause fuel consumption like that, and even if it was changed recently it could of been old stock and wore out / rotted quickly.
Also take the quick second to check the air filter make sure a rat hasnt made a nest in there, and jack up the front and rear tires to make sure they spin freely.
So if the issue is the FPR then there will be evidence with the fuel in the vacuum line. I'm guessing there is no FPR issue without that.
If it is not the FPR then there is some significant drag somewhere. Have there been issues with brakes dragging? Need to check this when cold and hot. Contaminated brake fluid could cause pressure build up when hot. Or maybe the levers or sliders or pads are binding. Have the brakes been cleaned and greased recently.
Another drag could be wheel bearings - but you should feel that with a free spin check.
In the vein of KISS, what is your warm up routine? Are you letting the bike run for a while before you ride off? I was involved with a conversation with a guy about mileage once and went through the possibilities, then he described a 30 minute warm up routine.
I usually try to let the needle get to at least the bottom line before riding off. Sometimes pull the fast idle for a minute or so (more often now since it doesn't really like starting in sub 20f temps).
Read all the replies and realized that I did have quite a bit of fuel gushing out of the hose that goes to the FPR. Will update once I swap it.
If the bike is idling, get on it and ride it. Nothing better to warm up the temps than to give it gas. It just doesn't make sense to let it slowly get up to temp, when the best thing for the engine is to BE at temp. Get it there quicker by putting more fuel through (riding). Same applies to cars.
Just don't ride HARD until the oil is fully up to temp.
Not only could this be a FPR issue, but it could be a sensor. IDK if the EFI computer has any error code read outs, but it could be that the computer thinks the engine is cold.
Normally this would be shown in the plugs, but plug reading can be tough as they can get washed out and read the last bit of a run.
Some used to do a run, shut the engine off during the run, then pull the plugs.
An A/F ratio meter would tell a lot. I made one from an O2 sensor and a multi-meter to help tune a carb. What's nice about an A/F meter is that you can look at the whole picture real-time.
As far as plugs go, I think most just stick with the stock ones and have no problems with them.
Whether or not he's warming up his bike too long, or his plugs are going bad, something still doesn't add up - he's going through 4 gallons of gas within 70 miles!! He should be going through less than 2 gallons. Where are 2 gallons of fuel going to??
It isn't leaking out - 2 gallons draining out in less than 70 miles would be quite noticeable, but he doesn't see any leaks or smell gas fumes.
It isn't being stolen - The bike is stored in a garage, so nobody is breaking in and stealing the same amount of gas every time he fills up.
Is it being burned? - He says the bike runs properly. Is it even possible for an engine to run properly while consuming more than twice the normal amount of fuel??
He said there's a lot of fuel gushing out of the hose that goes to the FPR. Probably don't notice it when riding the bike because gas evaporates pretty quickly, especially if you're traveling at speed, and whatever would drip is falling under the bike or blowing away. That could fully account for the missing 2 gallons when spread out over 70 miles or so.
There's likely not a puddle of fuel during warm up because the fuel flow is (comparatively) low. As you increase RPM and fuel flow, more gas leaks out, evaporates, etc. I would think a good way to test this would be to run the engine in neutral at maybe 2-3k RPM and monitor the FPR for leaks. That being said, he's changing out the FPR, so that may take care of the issue.
Last year my motorcycle was backed into by an unaware cager in a parking lot. I caught him as he was attempting to leave after already having picked up my bike and said there was no damage so he was going to leave. I asked him if he was blind because the side the bike landed on was completely Rashed. as a result the insurance company replaced the fuel tank with a brand new one. as the repair center normally does they tried to skimp on some parts and I was unsatisfied with the condition of the bike once it was finished. they were only trying to go for the insurance dollars and I ordered some cheaper parts then what was originally on the bike. the gas tank however was an OEM gas tank from Honda however they did use my internal float for my original gas tank. ever since then my gas light always comes on between 60 and 70 miles having been burnt. I'm sure it's just the sensor inside the tank is mounted incorrectly and causing this as I still get my normal fill ups and range around 140 miles per tank full. I'm also putting in around 3.5 to 3.8 on max fill. I know it's inconvenient however I decided not to take my bike back to that shop even if the insurance is covering it as I fear they might do more damage to the bike than good. It could possibly be when you lifted your tank you might have affected the sensor inside. just a guess on my part. Good luck with sorting it all out.
Lifting the tank will not affect the sensor at all.
Taking it out of the tank and reinstalling it will, if one is not careful. It's a long wire basically. Take out your fuel pump carefully and see if you can spot where it was bent and try to fix it.
That's all my tank will hold 3.5 gallons. Around 40 mpg x 3 =120 plus the .5 an extra 20 or so miles. I usually fill up around 125 or so I prefer not to push it.
Agreed. It might be bent too high within the tank which would cause the fuel light to turn on sooner. Rob has a great post regarding the fuel sensor. I'm on my cell so I can't search for it but if you or someone can find it for you, it would be worth the read.
Yeah it is a detail thing that although it bugs its really not hurting anything so its very low on my list of things to fix. I'll get around to it someday I'm not planning on selling anytime soon so I guess I'm that guy riding around with the light always on. As long as its not the Fi light anyways...
So I swapped the fpr the other day for my old one that I pulled last year (it wasn't the problem, so I figured I'd check if it changes anything before plonking down for a new one). Also an oil change and a cam chain tensioner swap (had the classic tensioner noise going on for a while now)
Ironically, as I pull up to my building on the way back (autozone parking lot is great for oil changes and misc work when no garage is available) my neighbor comes up and says the bike smells like gas.
Anyway, will update once I run through the tank. Thanks for all the suggestions!
Also, I tried running the engine at various rpms today with the tank lifted and couldn't spot any drips or leaks.
No.. but that probably needs some explaining as to where I'm at since I seem to be taking one step forward, two steps back...
When I had that whole surging issue last year that turned out to be the plug boot, one of the things we tried with my mechanic guy was putting the PC back on. This ended up a big fail as the bike wouldn't start at all with it and at one point or another, he ended up soldering the tps cable to the ECM connector as it was coming loose. that was the last the bike has seen of that PC3 (although I still kinda miss the extra pep it gave). Several months later the bike had a valve check and when I picked it up the TPM code was going off. We reseated the connector on the side and it went away, but came back intermittently.
Anyway, another issue that I created was that while changing the plugs, I had the bright idea of swapping the fuel filter since I had one sitting around from the PO and I figured it wouldn't hurt. Turned out that the one I had wasn't the right fit as it didn't have that curly line out of it and I didn't feel like hacking together hoses to get it to work. When I put it back together I must've bent the low fuel sensor rod as the light now comes on at 48 miles. Gotta get to that soon...
Sometime after changing the plugs but before swapping the FPR, I noticed the engine started kind of weird (revving it would cause the needle to come down slowly instead of dropping as normal). Restarting the bike made it go away and I went on my way, only to eventually have some strange surging and the TPS code coming back, more consistently this time. At first I though the surging may be due to one of the boots again, but that wasn't the case.
Then I remembered the soldering job and looked under the seat to find a black cable coming out of one of the ECM connectors looking kind-of loose. I tried to just stuff it back in until I had time to mess with it and the whole surging/TPS issue went away. I guess I need to re-solder it.
In any case, since changing the FPR, I put in gas once at 52 miles and put in 2.2 gallons.. so we're definitely not out of the woods just yet.
I've had a few 70-80 mile tanks this winter, but I attributed it to riding behavior. I use it for my commute, but that's only a five minute trip. So when it was cold (below freezing) I would turn it on and let it warm as I backed it out and put my gear on, then rode all of five minutes, then did it again for lunch and then coming home. So I guess it's not completely unheard of.
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