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-   -   carburetor "stuffed"? (https://www.horizonsunlimited.com/hubb/yamaha-tech/carburetor-stuffed-27707)

narkotik666 19 Jun 2007 12:20

carburetor "stuffed"?
 
okay....a while back, a friend rode the bike all day long with the choke out...sooo the bike got no air.....it wouldn't start after that....but after replacing the sparkplug.....that was covered in goop.....it started....blew out thick white smoke.....and after that starts beautifully everytime!

BUT NOW!!!! The bike is soooooooo bleeding slow that i dunno what to do.....nice in 1st.....okay in 2nd.....upto 80km/h.......and that's it.....can't go faster that 80km/h.....slow as hell......no feel in the throttle.....nothing.....it doesn't sputter or miss, it just doesn't GO!
with some searching...i assume that the carb is dirty and the needles/jets and clogged.

2 questions.....

1) Could it be that i just need to remove that carb and clean it.... could it cause me lack off performance?

2) How hard is it to remove the carb and clean.....got a repair manual....looks concise enough.....but threory and reality is like day and night....any things i should know/look out for,what should i use to clean it with....etc.etc.

Any help would be great! Thanks!

daytona 19 Jun 2007 15:00

Hey! No surging or missing? Sounds like you aren't getting wide open throttle! The choke you are mentioning is actually an enrichening system that will give more fuel not less air. Start with the basics and check oil level, air filter, fuel supply. A little trick! Run it with fuel turned off until out of fuel, (carb dry) blow thru fuel line it should have very little resistance. If it has you maybe running out of fuel. There is a filter @ the float seat that will get clogged. If you have run it on reserve lately you may have water in the carb which will cause what you are experiencing also. Drain the carb nothing needs to be removed but the drain screw.:confused1: :scooter:

narkotik666 20 Jun 2007 08:23

Thanks, sound like a plan! I'll give it a shot!


Another thing, the bike drinks fuel like a Supercar! The Fuel effeciency is shocking.....i get a 1lt/10km! EXTREMELY LOW! at 130km on a full tank i start worry about a refill........what could cause this? does this point more at the fuel bowl being clogged?

aukeboss 20 Jun 2007 10:58

First check the obvious
 
Your symptoms either are caused by too much fuel or not enough air (or both), things to check:
- Air filter: clean? If it looks clean, that does not mean that it is clean. Has a birb been caught somewhere in the air inlet?
- Carburettor: is the float level OK? I'm sure your manual describes how to roughly check with a transparent hose

Then, level 2: does the second carb open up, it is vacuum operated, does the butterfly valvve open as it should?

Auke

narkotik666 20 Jun 2007 13:02

brand new air filter.....and checked for birds! :)

How will i check if the valve is working correctly......it's going to be first operation on the carb.....so I'm a SERIOUS Newbie.......just took the bike for a ride...and it's bloody pathetic!!! up hills i give it everything she has just to keep it moving......about 40km/h!!!!! WAHT THE HELL IS GOING ON HERE!!!!

aukeboss 20 Jun 2007 19:14

Rustig maar
 
my South African friend ... technology is everything but frigthening :-)

First check your float level ... see manual.
BTW, absolutely sure that nothing blocks the air intake?

Then, as an afterthought, never a wrong moment to install a new sparkplug. Make sure the gap between the electrodes is 0,8 mm.

Then, the valve: if you look down on the carb from above (tank removed and other stuff), you'll see two tubes going to the cilinder head. That's the carb. Between the two tubes there's a mechanism, if you turn the throttle you should see the arm on the left hand side actuate an arm on the right hand tube. If that works, this is probably OK.

Important symptom btw is: does the bike produce black smoke? Sure indicator of bad combustion = low power.

Succes!
Auke

narkotik666 21 Jun 2007 08:10

HAAAAAA...I found the problem.......and believe or not it's not the carb....last night i got home and took of my helmet so i could hear the motor properly.....there was this funny gassy rattly sound....the wider i opened the throttle the louder the sound got......so as i checked for the source of this sound....................................I SAW BEAUTIFUL BLUE FLAMES POPPING out of the "hole" where the one exhaust header pipe goes into the motor....Now, I'm glad that i found the source of my problem.....but it looks like a serious problem.......the frame is even black where it spouts out fire....i assume all i need to do is remove the exhaust and weld the crack shut???? please tell me it's that....

Thanks for all the help so far btw.

Weird....we all want our XT's to be Fire Breathing Demons! ...hmmmmmm careful what you wish for i guess!!!

BOB UK 21 Jun 2007 14:03

Just a thought
Mybe the exhaust header pipe blow out because the exhaust is blocked
That would explain why the bike pulls ok at low RPM but has no top end

Worth a look

narkotik666 25 Jun 2007 08:23

BOB UK!!!! YOU are KING!!!! I took the silencer of, removed the little back end....and that little pipe was completely clogged......so i just chucked it!!! NOW THE BIKE PULLS LIKE A TRACTOR....throughout the rev range....AWESOME AWESOME!!!! THANKS ALOT!!!!! 100km/h in third in about 6sec. Where before it couldn't pull a greased pipe from a pigs ass!

Thanks alot!

photographicsafaris 20 Oct 2007 15:09

Same problem... HELP!
 
Really hoping that someone out there picks this thread up, Perhaps Narcotik66.

I experienced a sudden surge in power, just after startup, then heard the engine and upon stopping also saw the blue flames... most spectacular, Local kids shat themselves!

Now I removed the down pipes, but the connecting bits are very seriously attached to the cylinder head, Steel to aluminium job. Any pointers as to how to remove this mess, and also where in the UK to get a set of down pipes (cheap) or where to get repaired, Thanks for any help.

G

Walkabout 20 Oct 2007 18:54

You can make a start by reading this:-

http://www.horizonsunlimited.com/hub...t=exhaust+stud

There are other posts on other threads about the same issue; it is a common enough event for the exhaust studs to shear - you might want to do a search for similar key words if you really want to read more.

Good luck,


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