Topic: CB750K2 fuel in air filter and on engine

[jeremyillingworth]

Yesterday I had the tank off to adjust the valves and also the cam chain. I put it all together and any for a test ride, all was well. This morning I was about to start it up and there was a trail of gas leading from my parking spot to the bike. Gas was coming out of the fuel filter and running into the engine.

I assume this is not safe so I got a ride.

jeremy

[Powderman]

You'll need to drink all the oil from the motor and replace it, chances are fuel leaking in the motor runs past the rings and fills the crankcase. Not good if you ride that way.

[70CB750]

  that's a lot of oil to drink 

[DaveBarbier]

drink

Uhh


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1978 Honda CB550K

[jeremyillingworth]

Is this caused by a sticky float? Will pulling the bowls and cleaning them likely solve this until I can get new float needles?

[70CB750]

Do you close the petcock when you park the bike? 

You say fuel filter, do you mean the petcock bowl or are you using an inline filter?

The general consensus is that these bikes dont need more filtering than the sediment bowl on the petcock.

You should figure out where is the gas coming from and fix it.

Having gas in the crankcase is very unlikely in 4 stroke engine.

[jeremyillingworth]

That is supposed to say air filter, to match the title. The bike is all stock.

I don't normally shut off the fuel when parked by I likely did last night, which means it leaks a bit as well.

[jeremyillingworth]

[70CB750]

Well, follow the fuel, there is no fuel source in the air filter, how is it getting there?

[ekpent]

Well, follow the fuel, there is no fuel source in the air filter, how is it getting there?

If the bottom  drain vent or rubber tube gets plugged it possible for fuel to leak out the back of the carb into the airbox

[DaveBarbier]

That is supposed to say air filter, to match the title. The bike is all stock.

I don't normally shut off the fuel when parked by I likely did last night, which means it leaks a bit as well.

It's good practice to shut the fuel off. I always do, but sometimes I forget to take my key out! I need to work on that one.


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1978 Honda CB550K

[70CB750]

I would start by turning petcock on and watching -with the bike outside for the fuel to soak in the ground or old towel.  Seems like it happened after he put the fuel tank back, it will be something minor.

[70CB750]

That is supposed to say air filter, to match the title. The bike is all stock.

I don't normally shut off the fuel when parked by I likely did last night, which means it leaks a bit as well.

It's good practice to shut the fuel off. I always do, but sometimes I forget to take my key out! I need to work on that one.
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1978 Honda CB550K

Exactly!  When I started wrenching on my K0, I left it on just once and lost the whole tank.  Petocock ON  is only for the road.

[jeremyillingworth]

When I get home (it's only a three mile walk) I'm planning to take the air filter out, see where it's coming from if I can then drain/drop the bowls and see what happens. I'll do it outside over an EPA approved absorbent mat.

[jeremyillingworth]

I would think it would be a minor thing as it was working in the morning. Tank off, tank on then leaks. I'm due for an oil change so I have some at the house at least.

[DaveBarbier]

Not sure if your carb bowls went dry during the work you did, but sometimes a float can just get stuck in the down position. Often cured with just a rap on the bowl with the handle of a screw driver. EPA absorbent mat? They make those? My routine is usually to accidentally let it soak into the plywood flooring then get angry.


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1978 Honda CB550K

[jeremyillingworth]

The EPA mat was just a joke. We aren't subject to their jurisdiction here in Canada.

[hotelstationery]

I pulled the bowls off.  One had a small amount of water, one a bit of black stuff (very fine) and the other two nothing.  I checked to make sure the bowl overflows were clean and blew out all the lines just to be sure.  Two bowls took a couple of tries to get back on without leaking around the gasket, so I'll order up a new set tomorrow.  Can they be ordered singly from Honda?  All I see on the microfiche is gasket sets and float bowl assemblies.  Is there a part number for it?

While the tank was off I noticed that even in the off position that the petcock leaked a bit.  I'll order a GSKT, PETCOCK VALVE 16955-268-020 (the round one with the four holes) tomorrow and that should take care of that.

jeremy