jamessk98

Due to 2 project cars getting in the way of saving for another bike I'm having to sell my leathers before I have ever even used them.

I bought them brand new from sportbikeshop about a year ago and have only test fit once or twice.

I believe they are a size 44, will double check on the weekend.

Was hoping for £750 as they are still brand new, location is Bristol/ Telford and am willing to deliver if needed (if close enough).

Open to offers and of course will get photos of my actual leathers when I get home on this weekend

Feel free to ask anything

IF the fuel tap has failed and IF the carb doesn't shut off at full float height then

Fuel can lead into the Cylinder and cause hydrolock and bend valves which will cause poor running .

Gotta love vacuum fed petcocks

Gtr1000 renowned gor depositing 28 litres of fuel into as much of the engine as it could physically hold and the remainder on the floor

jesussssss christ, luckily mine wasn't quite that bad

It can get in via the crankcase breather pipe that vents into the airbox. This might not be the case on the CBR 125 , this is just general advice.

Oh okay, i was just wondering if there was anything i was missing. But on my bike the crank breather is just aimed out anywhere and isnt connected on the other end,

cheers anyway

Apologies to AMW I appear to be repeating your excellent advice concerning fuel draining into the oil . I've been through all this grief myself with my ER5, they are notorious for it .

Yeah the tank coming has that tap. But if it's still not 100% then i will look further into the carb. Or even get a different second hand one, i can see the adjustment screws have been mangled so everything is most likely way off and god knows what else has been done to it or whatever.

In terms of the oil, how does the petrol get to the crankcase? as wouldn't the only way be for it to go past the piston rings?

Autocock is a great word. They are also quite useful on a motorcycle, when they work!

My Honda CB500 also has a form of autocock to shut off the fuel when the bike is stopped, operated by a vacuum diaphragm.

While you are sorting it out and certainly before you ride the thing I would make sure that the petrol that could have been leaking out of the tank hasn't leaked into the sump and filled it up with petrol. If it has you'll need to drain it all out and throw it away and get some new oil.

This is an easy situation to diagnose as your oil shoudln't smell of petrol and the level shouldn't go up by itself...

The fuel only ever leaked when the tank was being taken off. So, from the time the rubber pipes were taken off to it being upside down. During that time all that fuel just want all over me really and not the bike

Does this look familiar ? http://i.imgur.com/nAILfp0.png maybe you are not alone .

 

I will have a read now about this, but my idle is pretty shocking from the start

I have read it and some does relate.

Only difference is that with mine no matter what it will go back up to 4000rpm, welllll it ranges between 3000-6000rpm.

The choke did also work normally before.

Also if I look down into the carb when I turn the engine off, it is very very wet and i can see fuel evaporate off it

Does this look familiar ? http://i.imgur.com/nAILfp0.png maybe you are not alone .

I will have a read now about this, but my idle is pretty shocking from the start

Right then , I've had a look and you are quite right, there is no fuel tap in the normal sense and again you are quite correct in saying that there is no reserve selector either. There is what is described as an Autocock which is the thing you have outlined in red . This device, based on its shape almost certainly contains a diaphragm that switches the fuel on when it is activated by a vacuum from the carburetor. From what I have seen so far, I don't think this thing can be opened up to replace the diaphragm. It seems that it must be replaced as a unit . So , provided you didn't pay too much for the tank and it's got the autocock still in it , that's that sorted then . However, even if this thing is stuck wide open, as I said the carb sill has a float and needle valve that controls the fuel flow into the carburetor float bowl. While I was looking, I was surprised to find that there does not appear to be a choke on the carb , instead there is a Starter Valve so that might be stuck ( see pics ) So anyway what I am basically saying is that a faulty autocock on its own will not cause over revving and spitting flames on it's own . http://i.imgur.com/S8esdqd.png see parts 15 & 7 maybe this thing is stuck . Also as previously mentioned by Tango, have a very good look at part 13 , this is the main diaphragm, check it for holes .http://i.imgur.com/gL3SwDJ.png

Yeah I only paid £30 for the tank with a new fuel level sensor (my current one is broken too) and the diaphragm valve moboby thing. So not too bad, especially considering a whole new assembly is £60-70.

I plan to replace it and go from there, as the choke moves freely as it always has done and that wasn't touched before the problem occurred. That is why I believe it is the problem and nothing else, but I'll replace it and see.

I'll just have to wait till I'm back from uni and what is what.

Fastbob is right.....If the fuel tap diaphragm was split, then you'd get no fuel to the carb.......maybe the diaphragm the garage was talking about is the CV diaphragm in the carb......no 13 in the diagram.

honda-cbr125r-2004-4-england-carburetor_bigecpp4e1e__1800_f455.gif

But if it is operated by vacuum then surely when its not connected no fuel would come out?

When I take the tank off, fuel pisses out of the top line of diaphragm with no vacuum

Yeah I know, hence the diaphragm being broken and stuck open, pouring LOADS of fuel in.

 

NO . There is a fuel metering device in the carb ( assuming this bike even has a carb and its not fuel injection ) consisting of a float and needle valve . A diaphragm in a fuel tap is operated by a vacuum from the carb intake . If a fuel tap diaphragm is damaged i.e it has a hole in it then it will not operate and you will get NO fuel. I'll tell you what , may i respectfully suggest that you get a Haynes manual called Motorcycle Basics and have a good read on what things are called, what they do and how they work . Once you understand the basic principles of things it will be easier to see what's wrong and put it right. I'm going to look at a parts list for this bike to see if it even has a petrol tap because there isn't one in your picture. There must be reserve function on this bike so it has to have a petrol tap .

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Then why would 2 people from the motorcycle garage both have said it?

I'm quoting from what they said, which was that one of the pipes go directly towards the cylinder.

And if its broken and no fuel should be coming out, why is it pissing out more than ever?

It will spit flames if its running RICH, it's the un burnt fuel that's igniting.

 

Yeah I know, hence the diaphragm being broken and stuck open, pouring LOADS of fuel in.

 

NO . There is a fuel metering device in the carb ( assuming this bike even has a carb and its not fuel injection ) consisting of a float and needle valve . A diaphragm in a fuel tap is operated by a vacuum from the carb intake . If a fuel tap diaphragm is damaged i.e it has a hole in it then it will not operate and you will get NO fuel. I'll tell you what , may i respectfully suggest that you get a Haynes manual called Motorcycle Basics and have a good read on what things are called, what they do and how they work . Once you understand the basic principles of things it will be easier to see what's wrong and put it right. I'm going to look at a parts list for this bike to see if it even has a petrol tap because there isn't one in your picture. There must be reserve function on this bike so it has to have a petrol tap .

.

And of course i know its not EFI, and it has no reserve tank.

As you say the diaphragm is vacuum operated, it if it broken then the fuel will go through the carb and also what was the vacuum pipe, meaning more fuel will go in.

It will spit flames if its running RICH, it's the un burnt fuel that's igniting.

 

Yeah I know, hence the diaphragm being broken and stuck open, pouring LOADS of fuel in.

 

NO . There is a fuel metering device in the carb ( assuming this bike even has a carb and its not fuel injection ) consisting of a float and needle valve . A diaphragm in a fuel tap is operated by a vacuum from the carb intake . If a fuel tap diaphragm is damaged i.e it has a hole in it then it will not operate and you will get NO fuel. I'll tell you what , may i respectfully suggest that you get a Haynes manual called Motorcycle Basics and have a good read on what things are called, what they do and how they work . Once you understand the basic principles of things it will be easier to see what's wrong and put it right. I'm going to look at a parts list for this bike to see if it even has a petrol tap because there isn't one in your picture. There must be reserve function on this bike so it has to have a petrol tap .

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Then why would 2 people from the motorcycle garage both have said it?

I'm quoting from what they said, which was that one of the pipes go directly to the cylinder.

And if its broken and no fuel should be coming out, why is it pissing out more than ever?

If it's been stood for a while try some fresh fuel.....but drain the tank first....

well the tank was empty till the other day, i put in 5L of fresh fuel on monday. there was maybe 150ml left in the tank over christmas and whatever was left in the carb too.

Really don't think fuel would cause this... you'd more likely find it bogging down on acceleration and having difficulty starting (dumping too much fuel in while sitting there and then hydro locking).

Air is what makes an engine go, hence turbos & superchargers are all about getting more air in quicker.

If air leak is ruled out and you're positive cable is not jamming then I'd look at carb, is throttle body closing correctly?

yes the throttle is closing properly, and i know for a fact the diaphragm is broken as all of a sudden petrol pisses out of the tap unlike how a tiny bit would dribble out and that would be all.

i assume its dumping loads of fuel but not too much to stop the running of the engine and enough to just have a high idle. It stopped running well all of a sudden after the lines had been put on the wrong pipes. I went to a garage and explained it to them and they agreed it would be the tap diaphragm.

I do also know how an engine works btw.

My sister's 2004 CBR 125R did havoc in a similar way on idle with a buggered throttle cable. I believe it was replaced and re-routed a bit.

I was thinking possibly, but the then it returns fine and is smooth. The idle was smooth at the start of the day and the throttle hadn't been touched or barely even moved

Yeah but a leak could still cause the idle to fluctuate? The two issues might be unrelated, which is why I suggest it may be sticking open once it’s been opened up.

 

I should have mentioned but it has been sat for a few months.

However it spits flames so surely an air leak will cause it to run lean right?

The problem wasnt there before christmas, but is now and i havent even touched the carb

 

It will spit flames if its running RICH, it's the un burnt fuel that's igniting.

Yeah I know, hence the diaphragm being broken and stuck open, pouring LOADS of fuel in.

What diaphragm do you mean ? The one in the carb or the one in the fuel tap ? The red line is around the fuel filter. Don't worry, it takes a while to learn all the correct terminology.

Yeah the diaphragm in the tap is the one that supposedly is broken now.

So I ordered a second hand tank off ebay so i can use the tap off that.

The throttle used to be on the handle bars, but for whatever reason the previous owner moved it under the seat, so no matter what i do to the handle bars it wont move.

 

 

Surely the throttle is on the bars, do you mean choke

Sorry i was rushing with the reply ahah, now i look dumb as shite.

I believe i have found what the problem is though, i believe the diaphragm is broken. I may or may not have accidentally swaped the lines the wrong way at one point

See attachment.

I sprayed some carb cleaning stuff in the throttle, and as i do that it bogs the engine down, what would this suggest?

 

How do you mean "in the throttle"? If into actual throttle body then all it suggests is you've sprayed carb cleaner into the carb if you spray onto carb and around joints (e.g. All the should be sealed places) and it don't affect it then nothing leaking and being sucked in. Leak would have to be inbetween throttle body and combustion chamber, basically it's allowing more air into combustion chamber as if throttle is open wider, normally that would not be sporadic as engine would just suck in as much air as it can get so would be over revving as soon as it fires up.

It does sound more like a throttle cable sticking issue or choke (does it have cable driven choke on bars or is it on the carb itself?)

I had first sprayed it on the rubbers where i thought the leak may be, then in the throttle itself to see what it would do.

The throttle used to be on the handle bars, but for whatever reason the previous owner moved it under the seat, so no matter what i do to the handle bars it wont move.

I pushed the choke all the way in so it wasnt on at all and not adding extra fuel.

But if i pull on it, the engine bogs down and runs slower

I sprayed it on the joints of the throttle bodies to see if it bubbled, that’s what I was advised to do when I had a fluctuating idle anyway .

 

Ok , but its an intake problem so its sucking IN unwanted air not blowing it out .

 

Yeah but a leak could still cause the idle to fluctuate? The two issues might be unrelated, which is why I suggest it may be sticking open once it’s been opened up.

I should have mentioned but it has been sat for a few months.

However it spits flames so surely an air leak will cause it to run lean right?

The problem wasnt there before christmas, but is now and i havent even touched the carb

I thought it was Easy Start that you sprayed to detect intake leaks . The idea being that if there's a leak the revs go up.

I sprayed it on the joints of the throttle bodies to see if it bubbled, that’s what I was advised to do when I had a fluctuating idle anyway .

I had also done that, was the first thing i did and nothing.

I then took off the inlet rubbers, no cracks or anything

I thought it was Easy Start that you sprayed to detect intake leaks . The idea being that if there's a leak the revs go up.

I sprayed carb cleaner, also highly flammable, and it just lowered the rpm

Check the throttle body for the leak, spray some WD40 where it could leak from to check. Also could the throttle body be sticking open?

I sprayed some carb cleaning stuff in the throttle, and as i do that it bogs the engine down, what would this suggest?

Also I just saw on the carb, from the previous owner, the other carb screws have been f**ked. so this may have something to do with the problem.

Although I never had this problem mid december when I ran it last, and nothing has changed since, as far as i can think

Still sounds like the cable isn't return correctly - especially if the idle adjustment doesn't work.

What happens if you waggle the cable where it attaches to the carb?

I just had a wiggle while it ran and it didnt do anything. And the idle screw does work, but only before it goes above 4000rpm

Choke stuck ?

I was thinking possibly that as its a bit f**ked as it is. However im not sure as it always has been f**ked and i had made sure it wasn't being pulled at all.

I will have a second look though and put some wd40 on the cable too.

But if it was the choke stuck open, would that not be all the time? as it only happens when i bring the engine speed above 4000, its a nice idle at 4000. Unlike below where it is all over the place. But obviously i dont want a 4000 rpm idle ahaha