What about the fuel

Hey guys. Here's an odd question. How old is old when it comes to the fuel. With the combination of hot weather and just being busy with the family otherwise, I haven't ridden much. The fuel in the bike is about 3 months old. Is it still good???? I know with Yami's 5 valve engines that good fuel is important, how old can it be?

Thanks in advance...Rushfan

I don't think you have to worry if it's only 3 months old.

If you feel that it's too old, drain it and use it in the lawnmower.

do you mean the fuel itself or the contaminants that can get to it ?

1. i am using 96 octane fuel which contains led. (led has good lubricating character).

2. it depends how quality is your fuel (fro the refinery)?

3. i stall my bike for two months and it was running well afterwords.

if you concern, you can clean your carb and fuel tank petcock.

4. if you still concerned, how much it will cost 2gal of fresh fuel??? :banghead:

Sniff it the fumes!

Seriously. If is still smells like gas, then it's probaly OK. Bad gas will get a funky kind of viniger smell too it.

Also, bad gas isn't going to hurt your motor. It's just going to run poorly. Might bog or stumble a bit. If it does, drain the tank and the float bowl on the carb and start with fresh.

Doesn't the octane rating go down when stored for long periods of time. Seeing how the yami's run over 12-1 compression, I would be slightly worried about detonation. Gas also "ages" faster in plastic containers than in steel. I don't think 3 months is enough to lower the octane rating that much, as long as it hasn't turned to paint thinner yet lol.

On the other hand, those bikes need 91 ( I can hardly believe they can run it as is). I usually would replace the gas or at least mix in some fresh gas.( takin the fuel line off is a lot easier than rebuilding the motor after it detonates a couple thousand times.)

Its been in the ground for hundreds of thousands of years! 3 months more ain't gonna hurt it!

Seriously though, 3months is nothing to worry about.

Water hurts fuel the most. Fuel absorbs the water moisture out of the air, especially with humid climates. That will be your biggest problem. You wont see water in the bottom of the tank or gas can, the water gets suspended/disolved in the fuel and you have to filter it out with a drying filter. (used on jet planes)

I have heard that UV rays from the sun reduce the octane, but that is not confirmed. Keep yer gas in the shade, or garage.

Thermal cycling (going from hot to cold to hot again) is probobly not good either, but that goes for any liquid (like beer)

My wifes bike sat for 4 months and the gas went bad. I drained the tank, put fresh fuel in it and it barely ran. I pulled the carb and when i drained the float bowl months earlier it did not drain completely and the little bit of gas at the bottom of the bowl turned to varnish. I have been told that refined pump gas now days has a shelf life of about 6 weeks. The demand for gas is so high now that long term storage is not a factor anymore so they do not add the preservatives to it like they used to. Also I have heard that storing gas in plastic cuts the self life. So if your in doubt change it.

6 weeks is about right...drain it, dump it in the cage and get fresh gas...

Wow. Thanks for all of the info. "When In doubt change it" Great advise!!! :banghead: If it were an xr it would be ok, but not a Yamaha...jk

Thanks for the help...Rushfan

Out here in Colorado my 01 WR426 gets very upset with me if the fuel gets more than about 3-4 weeks old :banghead: It gets harder to start and feels like it's down on power. A quick drain and change and it's happy again. I've also heard that our fuel here is formulated differently so who knows :banghead:

I've gone two months with no problems. Just gave it a quick sniff test and topped it off with fresh fuel. Never a problem for me.

I have let my bike sit for 2 months and used the gas in the tank without a problem. I do agree though, if there is any doubt the cost of prevention is much cheaper than the cost of repair.

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