carb help.

[rybes]

hello all. ive a request. is there anyone out there within a reasonable distance who knows more about carbs than i do thatd help me strip my carbs n check em ? i can take em apart clean and re assemble but i can never tell if anythins wrong inside as ive never really had much to do with carbs.
i got a funy feelin summinks wrong as i seem to have lost mpgs. i changed the o rings but that never really fixed it even tho the old ones were split. im runnin out of ideas now as to what could be wrong as i cant see anythin obvious.
at the mo im in england not denmark. any help any one could give would be great. thanks :D

[BruKen]

Before I say bloody anything I'm going to point out I'm talking about mikuni. Check your emulsion tubes haven't worn oval. I have two bikes with mikuni's on. The gsxr ones are diabolical and she's a thirsty pig. This is a common issue and maintenance item on mikuni's.24 quid a tube though the robbing bastards.

[rf9rider]

Is it just the MPG that`s gone down,, or any other problems?

[rybes]

mpgs dropped and i got a misfire at 7000. would like to invest in rollin road time í gotta find a job first tho  :roll:

[PompeyLad]

Where in Denmark are you living. I am up/over in Örebro in Sweden. Or do you have the carbs in England with you?

[rybes]

im near viborg till sat the 7th of april then im back over to england for a while. how long, no one knows  :(

[rf9rider]

Agree on the emulsion tubes, used to get the same problems on the Yamaha`s i owned.
Looks like a complete rebuild is in order, did mine and it runs fine now, although my tubes looked ok, i replaced all the o rings and seal.

[rybes]

yeah i got mikunis on mine. i was thinkin it might be on the choke circuit somewhere ? as one of the little brass pipes on the carbs was bust. was workin fine with good mpg fully loaded up. then i replaced the pipe and mpg dropped buy bout 30 mile a tank.
i wonder if it was runnin too lean before when the pipe was broke ? hmmmm

[BruKen]

What mpg are you getting or mileage per tank. I remember the tube you speak of, but that (unless its leaking externally) will not cause the issue. If the choke mechanism itself is sticking open, then yes it would, but that's easy enough to check too.

[rybes]

cant tell you mpgs im gettin but i was gettin 180 mile from full till the red light come on. now im only get 150

[CoolHandLuke]

cant tell you mpgs im gettin but i was gettin 180 mile from full till the red light come on. now im only get 150

Light comes on when you have about 9 1/2 litres left in the tank (with standard fuel level gauge).  When you have to switch to reserve, you have about 3 1/2 litres left.  This a very good approximation, but it is only an approximation because bumps and turns will give a +/- of about 1/2 litre.

If you are filling right to the top, you are getting a solid 25 litres in the tank, which means you are using 15 1/2 litres to do 180 miles.

180 miles / 15.5 litres = 11.612
11.612 * 4.55 = 52.8 MPG.

Obviously, the best way to check your MPG is to always fill to the same level and divide your mileage by the number of litres you put in the tank to fill to the same level.

[rybes]

as soon as i get back to england ill be fillin up n goin for a ride to see what i get out of it then pull the carbs for a look i think. check the tubes n choke circuit and condition and colour of the plugs. is it obvious if the tubes are worn ?
a rough guess at the min gives me 44 to the gallon.

[rf9rider]

as soon as i get back to england ill be fillin up n goin for a ride to see what i get out of it then pull the carbs for a look i think. check the tubes n choke circuit and condition and colour of the plugs. is it obvious if the tubes are worn ?
a rough guess at the min gives me 44 to the gallon.

If you look carefully at the tubes, they wear out, leaving the hole oval instead of round, sometimes it`s obvious, might have to get a magnifying glass  :)

[rf9rider]

If you look here Rybes, you`ll see the wear, look at the green inside the tubes, you`ll see the wear at the top of the holes

http://www.exup1000.co.uk/phpBB2/viewto ... sion+tubes

[rybes]

cheers for that rf. no0w i jus gotta find some green dots small enough to see any wear mine might have. i wonder where he got his from  
just in case, does anyone know the best place to get emulsion tubes and needles from ?