No Power

[semcintyre]

Well, what's not fun is being stranded on the side of the road... again. This time, no main fuse blown. It'll go a mile or two down the road, then spudder and die. Ugh!

[TOOLS1]

Fuel filter, line, or petcock screen plugged. Also could be the gas tank vent in the cap plugged.
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[semcintyre]

Thanks, I'll c what I can't check out. It starts and runs okay at low speeds.

What would make it only happen when I'm going along in a higher gear and speed, say 50sh.

I havent tested this yet, but I believe I could ride around all day in a 1-3 gear, low speed, higher rpm situation.

[TOOLS1]

Fuel filter, line, or petcock screen plugged. Also could be the gas tank vent in the cap plugged.
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[semcintyre]

Got it. Thanks!

That sounds like something I could probably tackle.

I definitely noticed some left over small flakes in the tank. I wouldn't be surprised if that was the culprit. Is the petcock screen easy to locate once pulling it off? Is the fuel filter itself located in the same area? I lost the electronic copy of my shop manual, need to track another one down.

Also, is there any chance that this could have been something my mechanic had done, like incorrectly adjusting the carburetors?

Shawn

[TOOLS1]

The screen/filter will be apparent when the petcock is removed. To check if it is plugged just pull the fuel line off, and turn the fuel on. Run it into a container for a few minutes to see if it stops flowing.
The CB 450 and CB 500 are the same bike, and the manual for them is in our manuals thread.
I doubt your mechanic put those flakes in your gas tank.
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[semcintyre]

So it appears to be a petcock issue. When I turn the gas on, nothing happens when the fuel is on. Although, when I have the tank off, and lift the tank backwards fuel does come out of one of the lines. I'm not sure what that's about.

I pulled the petcock, and tried to clean the filter surrounding areas the best I could. The two lines are clear and not blocked (air passed and visibly clear). I did notice that the rubber piece just inside the petcock was falling apart a bit.

I suppose the next step is to just find a new petcock and give that a shot? How can you tell if the fuel cap vent is plugged?

Here are a couple pics.

[semcintyre]

This appears to be the most promising purchase. I didn't inspect the ring, and the screen look dirty but okay. It's the rubber piece that might be bound up or something in there. I had trouble screwing it all back on, having the return in the back position.

http://www.ebay.com/itm/Genuine-Honda-Petcock-Strainer-Set-16952-341-671-CB400F-CB500T-CB550-CB750-/182510828462?fits=Make%3AHonda%7CModel%3ACB500T&hash=item2a7e7e3bae:g:xikAAOxyiklTk2Zb&vxp=mtr 

Let me know your thoughts. They're are greatly  appreciated.

Shawn

[TOOLS1]

You can still get those parts new from Honda for less $. http://www.partzilla.com/parts/detail/honda/HP-16952-341-671.html
Or here is a brand new one (I know it is for a CB750, but it is the same one as the CB500T) Just scrool down to Part #: 20-8038
http://www.vintagecb750.com/products/6/fuel-system/67/fuel-petcocks-gas-tank-caps-and-parts
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[semcintyre]

Gonna ask a silly question, where is the other output on that petcock? Seems to be missing...

[semcintyre]

[TOOLS1]

Good question. You can get a "Tee" at any autoparts store, and just split the line.
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[semcintyre]

So did a little more testing, and with the gas lines off the petcock, gas flows freely out...although, one side does flow slightly better. But with the with the lines on, I get nothing coming out. Seems like a pressure thing, but it doesn't matter if the gas cap is open or closed. It also matter at what angle the tank is, for example when the tank is level, I get nothing when the lines are on, unless I tilt the tank way back.

I'm sure this is just another dumb question, but what are your thoughts?

Shawn

[TOOLS1]

Lines plugged up? How about with just one line on it?
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P.S. When petcocks have two outlets, often when they are turned on with the lines disconnected from the carbs gas will only come out of one line, but if you plug that line the gas will start coming out the other line, and this is normal.

[semcintyre]

When the lines are off, they both flow pretty good... IF the tank is tilted back. When the lines are on, like you mentioned, only one flows. One of the lines is new, the other the original...need to verify it's not plugged, but kind of doubt it. The new line is clear, and I can see that gas is not going through it when the gas is on, all assembled

Yeah, it's puzzling. I don't understand why the tilting of the gas tank matters. The gas should be going down regardless.

At this point, since gas is coming out, would you still suggest a new petcock or filter/gasket?

[semcintyre]

Okay, so after talking to a buddy, he suggested putting it on reserve. Sure enough, that worked. I forget the rationale.

So about 3 minutes after finding a somewhat resolution to that particular issue, I pull into the garage after a spin around the block and gas is flowing out of the overflow drains. Apparently, the floats are now sticking

wth

[TOOLS1]

Well that sucks. Try smacking them with a screwdriver handle or soft hammer. Sometimes that will dislodge them.
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[semcintyre]

Tried smacking them... no luck . Any easy way to free them up without pulling everything apart?

[TOOLS1]

Smack them harder.
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[semcintyre]

Any ideas on why the bike would run fine for about 30 seconds, then starved for gas and verge of dying for 10, and repeat that? Hadn't noticed that pattern until today.