Petrolly Smell

[Kentish]

I have noticed recently then when I ride my bike harder than usual I get a petrolly smell from the carb rubber areas...I could smell it when I was riding and then when I stopped I smelt around and it seemed that it was coming from that area....I have recently balanced the carbs and my fuel screws are at 2.5turns....Maybe its normal I dunno

[Fazerider]

The tank will blow out a bit of vapour through the breather if you park it in the sun or after a run as the engine heat warms the tank, but the breather pipe should mean that comes out low down at the back of the engine.
You wouldn't normally smell petrol while you're riding though, try lifting the tank and have a good look at the underside and the hoses/pump/filter in case you've a tiny hole or split somewhere.

[stevierst]

It happened to me that. My tank had rotted through, and there were tiny holes forming in the bottom of the tank which started seeping fuel out.
I did a temp repair with chemical metal, and that lasted for a couple of years! :

[dBfazer600]

I get that all the time and went down the rout everyone has suggested but I could not find anything. I now do not fill up unless it is been run prior parking at home but I do notice that smell when my cover has been on a few days. I suspect that I may have over filled it a little at times and I am now very aware of that smell but I do love it  :evil

Daz

[Kentish]

This only happend to my bike after the carbs were balanced and a so called mechanic adjusted the mixture screws! I today wound them all back in and set them all to 2 1/2 turns as per the yamaha workshop manual.

Guess what? I took it out for a blast and there is no more smell. I think the so called mechanic has just made the bike richer...

[nick crisp]

Hmmm...whilst making you poorer... :lol

[His Dudeness]

You must have very sensitive nostrils  :lol

[Kentish]

You must have very sensitive nostrils  :lol

I didn't need them. It was very strong smell of petrol could smell it even with my lid on....

[His Dudeness]

How far out were they adusted? 2 1/2 turns is just a ballpark figure. They don't have to be set at that. They probably wouldn't be at 2 1/2 leaving the factory because they'd tune them specifically for the bike

[Kentish]

They were at all different settings. One was about 3 1/2 turns. Even I know they should all be set the same at not at different settings.

The Yamaha manual doesn't say 2 1/2 is a ballpark figure it says that they should be set to 2 1/2 turns. Thats the standard setting on a standard bike

[His Dudeness]

It is just a ballpark figure. If they were supposed to be fixed at 2 1/2 they wouldn't make it an adjustment point. It'd just be a fixed needle and they can be set at different points to suit different cylinders. 3 1/2 could be fine for that cylinder

[Kentish]

Well since I set them all at what the book says the bike seems to run better without smelling of fuel

[Kentish]

Also if the workshop manual states the factory setting for the mixture screw is 2 1/2 turns then that is what the bike would have been set at,at the factory. I personally wouldnt want to run the mixture screws at different settings as this would mean that the are not balanced correctly..

[His Dudeness]

Ok believe what you want.  Glad it sorted your problem anyway

[Kentish]

But why would u want one cylinder at 3 1/2 turns and one at say 2? One would be getting more fuel than the other so they would not be running even, plus you could be flooding it just to make it sound better hence the petrol smell I was getting

[ponkster]

It happened to me that. My tank had rotted through, and there were tiny holes forming in the bottom of the tank which started seeping fuel out.
I did a temp repair with chemical metal, and that lasted for a couple of years! :





The same thing happened to me - initially thought it was the tank breathers but then when I lifted the tank I could see the temp repair made by PO.


Its worth lifting the tank just to rule it out - not a disaster if it is - dont bother with repairing just get one off ebay

[His Dudeness]

But why would u want one cylinder at 3 1/2 turns and one at say 2? One would be getting more fuel than the other so they would not be running even, plus you could be flooding it just to make it sound better hence the petrol smell I was getting

Sound has nothing to do with it. No two bikes are the same no two engines are the same and no two cylinders are the same. There's going to be variations in everyting. Compression, spark, fuel supply, air leaks. If it's running better at 2 1/2 great but to say they all have to be set at 2 1/2 isn't right. 2 1/2 is a good start but it's not set in stone

[Kentish]

Well it's going on the dyno Monday so ill upload the print out to see what it's doing

[Kentish]

I hear you dude, same as no people are the same ie my mate starts his bike then fine tuned te mixture screws until the bike purs like a cat..I asked him what they were set at and his replied "fook knows" it sounds nice that's all I care about!!