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machina
the right side of the motor (3&4) quit firing. checked the plug leads but doesn't change anything.

could there be a problem with the carb? when I disconnect the linkage and push on the left carb the motor revs but when I push on the right carb it does not rev faster, only sounds different from opening the throttle plates.

sorry, I'm a carb newbie. blink.gif
Tom Perso
Since you've got your linkage apart... With the engine off, hit the throttle a couple of times on the unresponsive carb. If you look down the throat while you're doing this, you should see the accelerator jets squirt some fuel.

If you do, that means you at least have fuel in the bowl. If not, see why there is no fuel going in. It could be a stuck float... If it's stuck in the "up" position, it closes the fuel inlet valve. Give the side of the carb a good "rap" and see if it unsticks.

If you've got fuel in there, you've probably got some clogged idle jets. Take em' out and clean them. It's usually easiest to remove the carb to do this. Little pieces that are easy to 1) drop and 2) break.

Since there is NO difference when you move the throttle when it's running, I'm going to go for the stuck float.

Later,
Tom
MecGen
Hi
Turn motor off.
Look down the carb while someone presses the gas pedal.
You should see a steam of gas shooting down in both carbs.
Check for spark while motor is running, carefully remove the plug wires and see/hear a spark jumping.
After that you need to check the compression....
You will get a shock from the plug wires, it hurts its normal.
Good luck
Joe

beerchug.gif
jwalters
wink.gif I would go with a stuck float on this one--ifn you are opening up the plates while the engine is running and no change in rpms--means your mains are not flowing fuel either---mine did this only the opposite--mine stuck open and the pump was pumping all it could into those two cylinders, completely flooded it--gave it a good whack with a brass mallet and fine ever since....
Bleyseng
The same thing happened at DaveHunts fireoff party,

First check that the plug wires are connected in the right firing order .
Then check for the fuel delivery problem.

Geoff
machina
gonna check it out after breakfast...I'll try the mallet first smash.gif
machina
mallet didn't work.

how do you get to the float? Can you take apart the carb from the top with it still on the motor?
ematulac
On the Weber IDF's you can remove the filter and air horns and unscrew a couple of screws to pull the top of the carb off. This will get you to the float. Check the float and the needle valve to make sure that they are not stuck.


machina
got the float assembly off. the float seems to move freely and I can see the needle valve moving.

how can you tell if the needle valve is clogged?

also, the actual bowl is about 1/2 full of raw gasoline.
Aaron Cox
check the idle jets
Bleyseng
still say check the effin firing order.......but NO you gotta check out the fuel first. But did that work, no.

Look at the idle jets while you are in there and clean em out.

Then check the plug wires...


Geoff
machina
QUOTE (Aaron Cox @ Feb 27 2005, 03:00 PM)
check the idle jets

they looked clear but blew them out anyway.

Fact is that no fuel squirts out of the accelerator jets when the throttle is moved.

Should I pull the accelerator jets?

Oh yeah, the electrics checked out.
Aaron Cox
so you accel pump isnt working....

wierd... i guess search and destroy for a piece of debris blink.gif

Bleyseng
Ok, pull the carb and remove the accel pump cover.
check to see if the accel pump isnt torn or has a hole in it. Blow compressed air in all the hole to remove any crap.
Blow out the mains

try again.

Geoff biggrin.gif
rhodyguy
does this happen just at idle? if you run the rpm up 3000 do things smooth out? if your using a compressor to blow it out, turn the preasure down. the small cans of compressed air work very well. the long spray tips let you get up inside the idle jet passageways. in bob thomlinson's weber book, a diagram shows that for idf's the measurement from the top of the float to the botom of the upper plate as 10.0 mm, when the valve is in the closed position. if you are going to run carbs thomlinson's book is a must have. with the fuel line disconnected from the carb and you run the pump, there is fuel delivery, right?

k
machina
Much thanks to everybody........ smile.gif

Tore her down and it was the accelerator jets. Thought it was the one way inlet valve but in the end the jets were clogged.
Cleaned out the rest of it too. There was alot of corrosion in there for a nearly new carb. Maybe dissimilar metals problem.

Anyway, now she squirts like a charm.

When I woke up this morning I didn't think I'd be getting a crash course in Webers but I'm glad I did.
Aaron Cox
QUOTE (synthesisdv @ Feb 27 2005, 03:10 PM)
When I woke up this morning I didn't think I'd be getting a crash course in Webers but I'm glad I did.

fun isnt it!
rhodyguy
aluminum and brass may not rust, but they corrode like crazy. add a little moisture and it's like magic. nice catch.

k
Bleyseng
I hate carbs for this reason.. smash.gif
machina
QUOTE (Bleyseng @ Feb 27 2005, 05:49 PM)
I hate carbs for this reason.. smash.gif

yeah, I'm on the atkins diet actually.
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