07 WR450 called yamaha Customer Relations today

[Dan250]

I called Yamaha Customer Relations(800) 962-7926 about my fuel tank vent tube gurgling and leaking fuel onto the front fender after stopping. And my chain starting to eat the frame. They knew nothing and said there were no technical bullitens either and I would need to report this to a local dealer or they will never know. I can't believe they don't know by now. I called two local dealers and they are not aware of either. I have read here that many have gone back to the dealer and come out with overtightened chains etc. I am really frustrated about this. One of the dealers said he would take pictures and send to Yamaha for reference but they are 50 miles away. Or should I do like the rest and make a anti rub block for the frame and let the gas leak.?

[clark4131]

The chain rub is something that's been going on forever. Mine stopped when I got new adjustment blocks and paid more attention to its tension and position. The vent tube thing is new to me at least. Sounds like the valve may be stuck open or just bad. Get an aftermarket one and see what happens...SC

[JSanfilippo]

I've noticed the YZ 450f's subframe is mounted to a higher point on the frame pretty much eliminating the possibility of the chain rubbing the subframe. I wasn't happy about it at first, but like clark4131 said keeping an eye on the adjustment stops the chain rub completely. I keep it on the tight side and I no longer have any worries.

[Dan250]

I am usually good on maintenance chain tension and all, will try running on the tighter side. May still make some kind of rub block so if it is not exact I won't chew the frame.

I have tried several different vent hoses/check valves from other bikes and the ones that hold pressure in better I would find the tank exxppaannding and didn't think that was good.

[WGP]

Rememeber with the chain adjustment blocks that the hash marks are different on each one, chain side is 3 less than brake side...

[new2blu]

My vent hose does the same thing--I have some ideas to fix it but haven't got around to making something yet.

[SJMC_DON]

Rememeber with the chain adjustment blocks that the hash marks are different on each one, chain side is 3 less than brake side...

OK......... I'm confused

[kskyles]

Rememeber with the chain adjustment blocks that the hash marks are different on each one, chain side is 3 less than brake side...

are you sure about this one?? if so, i'm really misaligned on mine.

i usually measure from the bolt on the subframe, and it's only off by half a mark.

[KennyMc]

Both of the blocks are the same dimensions. The block on the chain side has a lip on it (for lack of a better description) so the marks don't start until the 3rd mark when compared to the brake side. So the 3rd mark on the brake side lines up with the 1st mark on the chain side (when looking from front to back).? When you look back to front, the 6th mark on both sides is in the center of the hole. That is why you need to count the marks starting from the back.

As clark4131 did, I just put some aftermarket ones on which are the same for both sides and eliminated this fine mess:thumbsup:

[Dan250]

Checked everything out closely and goes like this, bike has only 250 miles on it and this is now my second chain adjustment. Was still within spec not too loose. Tightened up 3 flats on the adjuster nut to bringing it just to minimum spec adjustment, made from the rear markings as the book specifies. Chain and sprockets all line up. Cleaned up frame scrapes with a small file and minor ones on sub frame. Since there was no real cause for this to happen I have no faith that this is the fix. I have had many other bikes and never had to baby a chain adjustment like this. Since I am not willing to shell out hundreds in aftermarket parts at this time to attempt to fix this, i'am going to make up an anti rub block like others have. Well enough of that thanks for the suggestions.

Now to tare into the gas cap and vent tube to see what is going on there, I suspect it is just too much heat from the engine...

[yamahead01]

thanks for the eye opener I just noticed what you are talking about while cleaning my bike after yesterdays ride I also have few miles and this is crap! my chain is also within spec this should not happen no matter what.