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the human bike-rack
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Discussion Starter · #1 ·
G'day

I went to fuel up this morning and met with great difficulty opening the fuel cap. And when I was successful in lifting the cap a smidgeon there was a loud smooching noise as air was sucked into the tank.

Has anyone else encountered this?

I'd just ridden a fairly easy 20kms, the temp guage was showing 3 bars, outside air temp was probably 20 Celsius and the tank required 16.5 litres to fill. The bike had its 1000km service last week but has had a fuel fill since then.

I am suspecting either a blocked breather hose (if there is one) or some other blocked or sticking relief valve. The bike still seems to run alright but now that I am aware there is a possible fuel delivery issue could be convinced the bike is running a bit like its strangled.

Any feedback/ tips would be greatly appreciated.

cheers ....kimbo
 

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I can't say I have any difficulties in opening my fuel cap. Could it be that your vent tube is pinched somewhere?
 

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Did you drive over any hills, or otherwise take the bike through any significant altitude changes? That could affect it. When I take my pickup to my moms place (~2hour drive over the hills) I fill up before I leave, then have to fill up again when I get back into town, there's some definite suckage, but if I'm just driving locally, there's little if any.
 

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the human bike-rack
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Discussion Starter · #4 ·
Yeah I'd agree with you Zeus that the breather tube is restricted in some way though after the 50km ride home from work this arvo and with a fairly full tank there was no problems opening the fuel cap? Just the same I will lift the tank disconnect the breather and give it a blow to be sure.

Nope Dexter no significant change in altitude but there could have been some significant changes in attitude (left /right) in those 20kms :lol

This was a bit more than the minor suction I often experience with my car- this morning it was to the point after several attempts where I was concerned as the the pressure I was exerting on the key in the fuel filler lid-lock (excuse the Japlish :lol )

cheers ....kimbo
 

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I too have had the same problem. The bike goes in for service for this problem on Thursday. My fuel tank is also loose. It has free play side to side by about 1/4". This allows the tank to rock side to side and hit the frame. I figured something is loose because now the tank rests on the frame which causes vibration up through the tank. It's been like this since 1200 miles (2100 miles now) and I finally got a service appointment.

I'll try to update this as I learn more on Thursday.
 

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Also along with this problem my fuel guage is not working. It never reads above 1 bar. Through all of this I have noticed zero change in performance or how the bike responds. Hopefully it's just a defect.
 

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This was a common problem on the previous 'Fazers' sold in europe, normally found after a bit of fiddling with the tank had been done and yes the breather pipes have pinched or blocked somewhere.

Although this won't cause you any problems in the short term you need to open the filler cap often till you get it sorted, it won't implode but there was a few members with mysterious flaking paint on tanks and upon further inspection it had deformed the tank under pressure, warranty claim if it does this..? You might be luckly if you can prove it was a service engineer that caused it so sort it before this happens.
 

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Livin' on the Edge!
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It seems as though I was wrong when I said that it is normal. (I deleted that ignorant post :)

I will have to raise my tank and look for a pinch in the hose. Sometimes it's good to find out I'm wrong and thanks for posting the question kimbo as I would have gone forever thinking otherwise and possibly cracking the paint on my tank. The tank sucks in quite a bit before the vacume is released.
 

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FAZR6 said:
It seems as though I was wrong when I said that it is normal. (I deleted that ignorant post :)

I will have to raise my tank and look for a pinch in the hose. Sometimes it's good to find out I'm wrong and thanks for posting the question kimbo as I would have gone forever thinking otherwise and possibly cracking the paint on my tank. The tank sucks in quite a bit before the vacume is released.
I just remembered something that happened when I raised my tank to put on my PC3. As I raised it to a certain height I started hearing some air noise. When I'd lower it it would go away. I was a little curious but didn't think much about it. Now I realize what it was which was the vacume releasing as the pinch or kink was straightened. Duhhhh! Damnit, that means the bike came new that way with the vent hose pinched or kinked closed. Now I'm a little pissed off that I didn't realize what was going on and fix it way back then. Guess I'll be raising my tank again and fixing it before I ride again.
 

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OK, here's the problem. If you look between the frame and tank on the right hand side (as you are sitting on the seat) with a flash light, you will see the vent tube. If it is kinked and pinched closed, find where the tube exits under the bike and pull it straight. I went to the trouble of raising the tank and didn't need to. Problem is solved.
 

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FAZR6 said:
OK, here's the problem. If you look between the frame and tank on the right hand side (as you are sitting on the seat) with a flash light, you will see the vent tube. If it is kinked and pinched closed, find where the tube exits under the bike and pull it straight. I went to the trouble of raising the tank and didn't need to. Problem is solved.
Yeah I always pull the hoses down after I have lifted the tank. I noticed this the first time I ever lifted the tank to get to the battery.
 

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FAZR6 said:
OK, here's the problem. If you look between the frame and tank on the right hand side (as you are sitting on the seat) with a flash light, you will see the vent tube. If it is kinked and pinched closed, find where the tube exits under the bike and pull it straight. I went to the trouble of raising the tank and didn't need to. Problem is solved.
Interesting

That still doesn't solve my non functioning fuel guage and tank resting on the frame problems, but it's one less thing I need the dealer to check. :)
 

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laimbeer said:
Interesting

That still doesn't solve my non functioning fuel guage and tank resting on the frame problems, but it's one less thing I need the dealer to check. :)
What happened to the black rubber blocks that the tank rests on between it and the frame. They are square rubber blocks and there is one on each side a few inches forward of the seat
 

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FAZR6 said:
What happened to the black rubber blocks that the tank rests on between it and the frame. They are square rubber blocks and there is one on each side a few inches forward of the seat
Those are still there and functioning as they should. If you look towards the front of the tank, you should have 1/4" or more of a gap between the tank and the top of the frame as noted in red in this pic:



My tank rests on the frame at that point. I don't know if something became loose under my tank that I am missing, but so far I can't find the problem. At the same time my fuel gauge stopped working correctly, so it's going to the dealer now. (this pic was taken prior to the problem)
 

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The rubber grommets may be missing under the washers on the forward tank hold down bolts.
Not sure of your exact setup...
Had this happen to me on my old bike.
 

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the human bike-rack
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Discussion Starter · #16 ·
G'day all and thanks for the feedback

I lifted the tank to find indeed the breathe hose was kinked, to the point that the hose has err wrinkles at the site of the kink. Man that hose is soft. I will try and fit some hose that won't kink but still make that tight curve directly under the tank- failing that I'll check out putting an elbow in much like the elbow to the CA models anti-tip-over valve.

Glad to hear I don't have to lift the tank to check on and straighten the breather hose.

I am wondering Liambeer if your tank isn't properly attached at the rear, something like the bolt that makes the axle of the hinge joint being missing- that would permit the lateral movement and would let the tank sit lower...

This forum is the best, the info and tips here are golden and of course its great to meet so many passionate FZ6-ers

cheers ....kimbo
 

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jk750 said:
The rubber grommets may be missing under the washers on the forward tank hold down bolts.
Not sure of your exact setup...
Had this happen to me on my old bike.
Nope, still there.

The bike goes in at 9AM today. I get this really bad feeling after reading this thread that the suction has caused my tank to deform causing it to rest on the frame. :(
 

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Alright folks, just picked her up. As FAZR6 said above, my vent tube was kinked. The service tech said it actually had multiple kinks. He said it was the fault of whoever setup my bike originally. Either way, the kinks did not allow the pressure to relieve itself causing the tank to gradually deform to the point where it came to rest against the frame. Most of the deformation was not visible until you lift the tank, but when he showed me another FZ sitting next to my bike, I could see that the outside had deformed as well. I didn't notice because it happened slowly over time. Seeing as how the tank was misshapen which allowed it to rock side to side, the resistor that measures the fuel level was jarred loose from the shock of any number of bumps I may have hit while riding.

Initially Yamaha did not want to allow a warrenty claim. The dealer told them that this was my first Yamaha and I had expressed interest in a Yamaha cruiser as well and they could lose a potential lifelong customer. So in good faith they are going to fix the guage and replace the tank under warrenty in two weeks. The tech also said my chain was a little loose, so they are going to do a full top to bottom service for me at the same time for a measly $120. That is everything but a valve adjustment. After 2500 miles, my baby deserves it especially just before winter storage.

So, don't let this happen to you. If you have suction when you open your fuel cap after a ride, fix your pressure valve tube under the tank. You'll save yourself a lot of grief.
 

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After hearing about what happened to you, Laimbeer, I feel very lucky that this question came up. Glad Kimbo was sharp enough to realize that this wasn't normal and pose the question. I'd like to know how many other people had kinked pressure relief hoses on their bike. I'm guessing it's a pretty high number and a widespread problem. If you don't mind, post a yea or nay. As you can see, this is a very serious problem that everyone needs to pay attention too. I feel pretty stupid that I never questioned it myself.
 
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