Tank Breather ??

[Kiwifruit]

From time to time the bike develops a strange issue. It seems to run out of fuel. Seems worse when coming to a stop, the fire just goes  out. It will restart and then run like a hairy goat.

[KiwiCol]

Is this the same issue that remedies itself when you open the fuel cap?

[Kiwifruit]

Yes Col.
....l had just written a novel about how it cheers itself up once you open the fuel cap. But fell asleep and lost that bit 

[KiwiCol]

You should start with 1 thing at a time, do this & see if it helps, no? go on to the next one.  Start with new gold link chain & sprockets DID 530 heavy duty. Then right angle valve stems & mirror extenders. Change headlight bulb to a +130 version. Obtain & fit new Yoshi cam & PC5 with a full Akra system to help, then some dyno time.  After this lot, I'm sure she'll be right, but if not, you may have to go the 1550 route. 


Dr Col has remedied this issue, next patient please . . .

[seth]

We're you reading my mind @KiwiCol
Thats what I was going say to do
Don't forget if the 1550 kit doesn't work go to 1700 and then it's got to be a turbo or it'll never be right .

[KiwiCol]

Correct Seth.  Where would we be without you to add the essential detail.  I've heard there's a supercharger available as well, which could be a last resort if the turbo doesn't remedy the situation.


Get the wallet out KF, we're fixing it for ya!!

[KiwiCol]

Right, beside all the above excellent suggestions, does the actual cap have a small hole in it somewhere to allow atmospheric pressure to be maintained in the tank?  I'd say it does - somewhere.  I know if I forget to turn the on / off switch on top of the fuel cap on Cheries honda, it'll run for a while then die. 

Just thinking it could be the same thing, partially restricted breather in the fuel cap itself.  Dunno if it's possible to dismantle & have a look inside? I'd say it would be.


Off to Kaikoura now, Mrs has me doing some maintenance before I can go out on the quads.

[seth]

There is a small breather hole in the cap and then there is a breather it's the small hole between the filler cap hinge and the filler hole .
That breather then goes into a pipe that ends in the area of the swingarm pivot and is easily kinkedand needs to be routed correctly .
I'll add a pic of the routing in a mo .

[KiwiCol]

I wouldn't of thought a blocked / kinked water drain - overflow hose would cause this. Be more likely the pin hole bit in the cap has a bit of shite randomly blocking it.
I'd disassemble n check / clean it n see how it goes then.

[seth]

It can only be one of those so just work through it you'll get to the bottom of it .

[Kiwifruit]

310kms today, didnt miss a beat. It is such a random thing that happens.
When l left home this morning the gas was to the hole l made in the tank neck. Be lucky to get another cupful of gas in

It can only be one of those so just work through it you'll get to the bottom of it .

[seth]

These are the very worst kind of fault in anything .
I just want things to work or stop working then it's easy to find and repair .
Good luck buddy hope you find what's causing this problem

[Kiwifruit]

So the hose that tucks in behind the swingarm pivot I thought was a breather is in fact a water drain and fuel overfill / spill drain hose and not a breather hose at all.

[seth]

I knew it was an overflow/drain but I also thought it acted as a breather too.
Everyday a school day .
Your problem can must be fuel cap related then as that's the only thing that can restrict air getting back into the tank.
When your having this problem if you open the tank can you hear the air getting sucked back in to the tank as that's also a clue.
The thing to check is the tank releasing excess pressure (venting out) on a hot day .

[Kiwifruit]

I've been listening for that suck when you open the cap. Nothing l can hear.
Fortunatly its very rare that it does it. I can ride a tank of gas out and have no issues so that tells me it is venting.
Will check the fuel cap if l can