Just pulled carbs apart and....

[speeding_ant]

Hey guys,

Just pulled my carbs apart last night and gave them a clean. The engine runs, but without choke the engine dies at idle. Also splutters and backfires when trying to accelerate. Would anyone have any ideas on what this might be?

Thanks a lot

Andrew

[Wasp]

idle adjust?

[FROSTY]

KISS it dude---start with the simple stuff--make sure the carbs are in the manifold propperly and the clips are all tight. Ditto the airbox connection.
Check you have the vac hose connected.
possibilities inside--jets in the wrong placce--You have blocked something up thinking you had cleaned it out

[Motu]

Think of something totaly unrelated and replace it - the coil,that it...the coil is faulty,so replace the coil,and the plugs,leads etc.

Was it idling before you pulled it apart? If it was idling then and not after you fiddled with the carbs.....then I'd take a guess and say it was something you have done and not the result of an alien spaceship parked next door blowing the coil.(it happened to me,that's how I know these things) Go over everything you have touched.....that's where the problem is.

[Wasp]

I guess this is kind of my fault - I was supposed to help but seem I got taken out by that 4wd I couldnt :(

sorry Andrew

[speeding_ant]

Thanks for your help! Its obviously something ive caused! Oh well, I'm about to pull them apart again, see whats happening. It was fun though, learnt a lot about how they work..

I'll let you know how it gets on :yes:

[Horney1]

In addition to Frostys comments:
NEVER clean any jets with a piece of wire. That little hole that the fuel flows through soon becomes a bigger hole and it'll never run the same. And never screw the screw adjusters in hard (the finely tapered thingys often with a spring and o-ring on them) that'll stuff them to. I think jets are usually pretty hard to mix up. A wash in turps (later edit: sorry anyone who's read this before I got back to edit it, think it may actually be kerosine I was meaning - still not quite sure!) then water then a shot of compressed air is a good start for the whole thing. BUT MAKE SURE YOU HAVE REMOVED EVERY spring, retaining clip, jet, seal etc before doing that. If you blow something away & lose it you're stuffed until you can replace it (that's if you know what got blown away!)!

Check the condtion of the needle valve that lets the fuel into the bowl. There should be a clean taper on it with no ring or damage where it seats against the other half. Replace it if it's worn.

Very important is an absolute seal between carb & intake manifold and inlet manifold & head, including no cracks in the rubber manifold. The airbox side isn't so important but best is that it seals well. Check your fuel height in the bowl (fitted) or float height depending on your specs. Recheck all standard settings are set as they are specified. I assume you have the specs? If not, get them.

I think you've got multi carbs, don't you? If so they'll need to be balanced for best performance. That's so they all do exactly the same thing at the same time. Could be a bit beyond you, but if you want to attempt it you'll need a set of vaccum guages and some more advice... It should run without that though.

Failing that try replacing the coil (if you had an alien visitor next door)

Good luck

[El Dopa]

Think of something totaly unrelated and replace it - the coil,that it...the coil is faulty,so replace the coil,and the plugs,leads etc.


Heh. Just got my bike back having had the carbs cleaned and rebuilt. And trying to put them back on the bike myself. Turns out that not only did the carbs need a clean, but the coils were rotten. And one of the leads was duff.

[Horney1]

Sorry anyone that may have rushed out and washed their carb in turps. I think it should be kero!!??

[nallac]

had the same problem with a bike i just brought.
stripped and clean carb/pugs still no good dumped gas sand blasted plugs fresh gas and away she goes.two hours spent messin with carb for nothin.
Just crap nz gas.

[crack]

Hey guys,

Just pulled my carbs apart last night and gave them a clean. The engine runs, but without choke the engine dies at idle. Also splutters and backfires when trying to accelerate. Would anyone have any ideas on what this might be?

Thanks a lot

Andrew

Take the air cleaner off.

Turn fuel supply on.

Wait a minute.

Turn fuel supply off.

Dissconnect hose from fuel supply outlet.

Blow through fuel hose, watch carb bell mouths.

Do this a couple of times.

Then connect up fuel line, and start.

See if this makes a difference.

You may have some crap stuck on the insides.

If it doesn't work, then pull them off again.

When you work on carbs, work on one at a time, and put the same parts back in the same place.

Area hygiene is important, IE: a clean area to work, clean cleaning bowl, etc etc.

Did you replace or make any gaskets???

Did you re use your fuel, or use new fuel.

Was the machine running well prior to you pulling the carbs apart.

[speeding_ant]

Take the air cleaner off.

Turn fuel supply on.

Wait a minute.

Turn fuel supply off.

Dissconnect hose from fuel supply outlet.

Blow through fuel hose, watch carb bell mouths.

Do this a couple of times.

Then connect up fuel line, and start.

See if this makes a difference.

You may have some crap stuck on the insides.

If it doesn't work, then pull them off again.

When you work on carbs, work on one at a time, and put the same parts back in the same place.

Area hygiene is important, IE: a clean area to work, clean cleaning bowl, etc etc.

Did you replace or make any gaskets???

Did you re use your fuel, or use new fuel.

Was the machine running well prior to you pulling the carbs apart.


I'll try that thanks, there might be. I took it for a ride down the motorway, its fine at constant revs, sitting at 10000rpm. Didnt re-use gaskets, just greased them a little to make it seal. Fuel was new in the carbs and tank. It ran OK but idle was a little crappy, wasnt as powerful as it should be. Seemed to be running a little rich too.