Huge Carby Problem ( I Think )

[Millaz88]

Hey guys just after your opinion

On the weekend I thought I would have a look at my carby as it won't open the secondaries and always idles high so I had a look to make sure all the vac lines were on and had a play with the levers and things to see if maybe anything was seized or loose couldn't find anything wrong

Now it started running better after I played with the levers and things and idled at a normal rev so I was happy then on my way home from work it started playing up a lil bit then I it's started idleing high again and then all the sudden just dies and other times it just looses acceleration

This would be meaning the carbys shagged and needs to be replaced wouldn't it??

[altezzaclub]

Nope- nothing that simple!

 

Look for inlet leaks... is the carb bolted down correctly? is the manifold bolted to the head firmly? Spray some CRC 556 or similar on all the gasketed joints and see it it changes the idle speed.

 

Are the vac lines all in good repair? No broken sensors (like the tiny plastic ones at the thermostat housing) or split hoses?

 

Is it vacuum secondary or mechanical secondary? Its easy to see if the mech secondaries work, but much hard with the vac ones.

 

Basically you need to sort out any external problems before you tackle the inside with things like fuel needle and seat. It could be a leak in a gasket that wouldn't change with another carb, or it could be a dead simple problem in the carb. An inlet leak would let it idle high and being lean would rob it of power, but you never know....

[Millaz88]

All the ac lines seem fine none are cracked or anything

It's a vac secondary

A mate played with the mixture now it's even worse lol

All the rubbers on the carb are perished as and missing

[altezzaclub]

Ah- so how do you know this..??

 

as it won't open the secondaries

 

Just doesn't go above 3000rpm?? Power dies suddenly around then?? It just keeps accelerating through 3000rpm but doesn't surge?? You used a webcam & a laptop while driving and saw that the lever not moving?

 

I dunno- could be a few things and maybe its easier to slap another carb on. Certainly you should be able to set the mixture- get it warmed up, screw the mixture screw in until it dies then screw it out again, and get it to where the idle is as high and as smooth as possible. You can alter the throttle screw to change the speed if it gets too low or too high.

 

Let us know how many full turns from "screwed right in" is the best idle.

 

Which rubbers are knackered??

[Millaz88]

Well it just surges most times driving to be honest

It does rev past 3000rpm but realy struggles when it gets to about 4000rpm and then pretty much when u back off it just wants to die like it sucks it dry of fuel but I don't know

Is the mixture the brass screw with a hole thro it or the steel long one?

[Millaz88]

Ok fixed guys

Loomed at the other carb in the shed n worked out it was missing a washer on the large lever thing that sits onto of a spring thing and it was all the way down instead of all the way up so put that in and bang works better now

Still needs a tune but it's a million times better thanks guys

[altezzaclub]

hmm... pump jet piston??

 

Still, you learn as you go.... A full strip and clean with a manual and you would learn all about it.

[Millaz88]

Pump jet piston would be rhe one I guess

 

Yeh I think I need a manual so I know what things are called and how they should be

Once I get my tax return I'll be upgrading the carby I hope to a quad bike carb from a cbr1000r

Hopefully

[Evan G]

all fixed by me :D

 

idle set to high and WAYYYY too rich.

 

now she puuuurs

[Millaz88]

Yes thank u even g now it runs like it should lol and doesnt feel like your going up a hill above 4000rpm

Cheers man

Miller