Fuel supply question

Pulled the tank off tonight, left it set to "On", if I shake the tank a few drops dribble out of the gas port, I set it down on the ground and so far no gas has leaked out.

Does it sound like I need to rebuild it? or is it normal that shaking it would let a few drops leak out. Maybe 1/2 a teaspoon of gas each time I shook it.

I also pulled the carbs out, took off the bowls and they are already crudded up from sitting for 8-9 months. I didn't drain the bowls over the winter.

After looking at the bowls and trying to remove the drain screws, it turns out I wouldn't have been able to drain them, all 4 are stripped, not horribly so, but a few squirts of WD40 and sitting for 30 minutes was not enough to loosen them up.

Would kroll be the best to try to free them up? If I can't get them then, is a dremel and a perfect fit slotted screwdriver still the best method?

Hoping to get a response before tomorrow noonish, as I'm going to go to my local Yamaha shop and see what kind of parts they carry for the carbs. And I'll compare prices with Chacol and if they aren't to crazy may buy local just to save the wait for shipping. Plus I like to support local businesses when they aren't crazy priced.

Oh, and my air filter weights about 2x it's normal weight, it's full of oil/gas.... The bottom of the airbox has some oil and crud in it too, so an air filter is on my list of parts to get now too.

2 of the 4 float valves have the screens dented up, the needle doesn't reach up that far, but could that somehow be causing them not to seal up too?

Sorry for so many questions, didn't want to start several threads.

Thanks,

 

you know it's vacuum operated, right? when set to either "ON" or "RES" it only flows fuel if that other little hose sees vacuum from one of the taps on the intake manifolds. Switch it to "PRI" if you want it to dump out while the bike is not running. Note that where it is set is based on where the teeny tiny invisible arrow on the lever points. usually away from the lever itself.

WD-40 doesn't actually do anything to break up rust n such. Kroil, PB blaster and the like actually catylize it away more or less. They also have some chemical included which isn't springing to mind that does a better job of fitting into tiny spaces (we're talking one molecule being smaller than another here and having less surface tension)
I would recommend cleaning them all out real good so you don't burn the place down while heat cycling the surrounding bowl. Also an impact driver. but hanging onto the bowls to use it is a PitA.

somebody ran it too full of oil and/or let it sit so as the crank case filled with water/gas/oil mix then cranked it over a few times.
Change the oil to the correct amount, sort the carbs. once it's running any remaining water will cook out.

forget about those screens. clean 'em and if you bust 'em right apart while cleaning them then good on ya. you need to be running an inline filter in the hose between the petcock and the carbs

 

See? What'd I tell ya?

All good advice; I'll elaborate on a couple of points:

You will get a few dribbles of gas out if you shake it vigorously enough, shaking it in the right (wrong?) direction will make the little diaphragm valve inside the petcock move and release a dribble of gas.

Not necessary to drain the float bowls over the winter if you use a gasoline stabilizer. Then, you drain them in the spring before starting the bike.

You already know about Kroil, get some: http://www.kanolabs.com/google/ WD40 is designed to displace moisture; it's about useless for anything else and DO NOT USE IT as a cable lube. It gums up quickly when exposed to heat, you don't need a sticky throttle.

The best way to remove stuck float bowl drain screws is to remove the bowl, and screw it down onto a scrap of lumber. Then gently apply heat from a propane torch, and unscrew the stuck screw.

If your local Yamaha dealer doesn't charge you 2X or 3X what you can get parts for elsewhere, that's downright awesome. My local Yammery wants $15 for the same FRAM oil filter I can buy at Advance Auto for $5.

If the air filter's saturated, replace it. It won't "cook dry" and it will affect how the bike runs.

And as far as the "beanie" screens: I used to be of the "pitch em, you've got an inline filter now" school of thought; but I've crossed over to the "replace them, they're the last line of defense against a stray hunk of debris" camp. (We got jackets.) So replace them, they're the last line of defense against a stray hunk of crud.

The beanie screens won't keep the float valve from working, no. Remove the float pins, floats, and the needle valves. Carefully examine the tip of the valve plungers; you're looking for a ring worn into the rubber tip or it being no longer flexible, or in some cases, missing. If the rubber tips on the needles are sharp and pointy and smooth and flexible once cleaned, they're ok. Look INSIDE the valve seat; clean and polish the inside where the needle sits. If it has wear or pitting such that it won't polish up and provide a clean seat for the needle to shut off against, then replacement is in order. Quite often, especially in the case of a reasonably low-mileage bike, the parts are fine and just need a good cleaning.

 

What about Chacol's kits that don't include screens? will my existing screens fit his kits if I end up having to replace the valve assembly?

I will look closer at the needles and valves, I actually thought they were completely metal, didn't realize they have rubber tips.

I will try the scrap wood and heat, and if no go then will get some Kroil.

I was wondering how I was going to hold the bowls, didn't really want to put them in a vise, after playing with them it makes you realize that they are actually quite fragile.

Is there any way to "test" the needle valve assembly without putting the whole thing back together? Has anyone found a way of testing the seal outside of the carb?

Thanks,

BTC

 

You have to put it all back together, and supply the rack with fuel, to set the float levels anyway.

You should be able to tell by inspecting the valves and seats whether or not they've got any hope of sealing.

Get some Kroil anyway; it's something you're gonna need for more than just this.

 

I looked this morning, all 4 needles have rubber tips, but if I push them up into the valve seat, they rotate freely, shouldn't the rubber cause them to have some resistance when trying to rotate them?

My local Yamaha shop has the replacement needles and seats (They claim are OEM and identical in size/shape) for $63 each including the screens.

Anyone know if Kroil can be bought in stores, i.e. automotive shops, etc?

I picked up my cleaning supplies this morning, so will be working on getting them back to clean condition again, then will work on the float settings and make sure they aren't leaking.

Thanks again for the tips,