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Maintenance Tips and Tricks for the T3 Classics Maintenance tips, tricks, performance suggestions and proven setups for the Hinckley Classic Triples.

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Old 07-14-2007, 08:13 AM   #1 (permalink)
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My 1999 Legend TT is new to me. On arrival back in my garage after a short 3 mile ride home from work, with the engine off, there is a faint whistling noise. When I remove the gas/petrol cap there is quite a vacuum in the tank. Is this normal?
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Old 07-14-2007, 08:17 AM   #2 (permalink)
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There is a tipover valve located at the left hand side rear of the fuel tank. It is a couple of inches down along a hose. check that the hose isnt kinked, and that the valve is vertical.
This is quite commonly the problem. Have you had any fuel starvation issues?
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Old 07-14-2007, 09:30 AM   #3 (permalink)
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Yes - I have been trying to solve a missing/hesitation problem.
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Old 07-16-2007, 03:51 AM   #4 (permalink)
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Take the hose off the tank with the valve attached, hold it so the valve is vertical and blow through it from the long end of the hose.If you cant blow through it you have trouble, it will have some resistance, but should allow a small amount of air through. If that doesnt work blow from the other end to make sure it isnt installed upside down.
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Old 07-16-2007, 10:12 AM   #5 (permalink)
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also check the poppet valve in the middle of the gas cap - little white round disc right in the middle it should be free to let air in - suck on it to see if it is blocked if it is just poke it until it works.

It is most likely the tipover valve - check the hose for kinks and make sure the valve sits vertically.
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Old 07-17-2007, 12:29 AM   #6 (permalink)
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That fixed it

Yep - the tip-over valve was horizontal, so I re-threaded the breather tube so it hangs vertically and there is no more vacuum. Thanks for the pointers.
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Old 07-17-2007, 06:24 AM   #7 (permalink)
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I had the same problem and took off this valve.
What is function for that?
I thought it was paint flakes/jelly problem.
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Old 07-17-2007, 07:47 AM   #8 (permalink)
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Quote:
Originally Posted by jukka_kanerva View Post
I had the same problem and taked off this valve.
What is funktion for that?
I thought it was paint flakes/jelly problem.




The valve is to stop fuel spilling on the road in the case of an incident. It actually works too.
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Last edited by WoodsieIII; 07-17-2007 at 07:49 AM. Reason: Double quote
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Old 07-17-2007, 10:02 AM   #9 (permalink)
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Yup if your bike ends up horizontal then you will have the equivalent of a 1/4" hole in your tank letting gas flood out if you don't have the valve fitted. What I have never understood is why they don't more securely attach it and its hoses as it tends to fall off and get lost. Cable ties can help here.

Spilled gasoline after bike accidents was actually cited in the Hurt report.

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Fuel system leaks and spills were present in 62% of the motorcycle accidents in the post-crash phase. This represents an undue hazard for fire.
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Old 08-10-2009, 01:27 PM   #10 (permalink)
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Missing/hesitation problem

I too have a slight whine noise coming from my gas tank.

I think I have a hesitation problem, but I am not sure. When accelerating, my bike sounds like it is firing two cylinders and is sluggish. Opening the throttle more causes the bike to sound and accelerate like it is running on all cylinders. Is this characteristic of a problem with the tipover valve?

Thanks!
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