Kangaroo on little throttle

[wilson]

My 1.8 Clipper Carb, now starts fine all the time and accelerates fine runs fine accept when sitting at a constant speed, when accelerating with the throttle open it accelerated really smooth, but just open the throttle a little bit it wants to cut out and sitting at a level speed wether it be 30 40 or 70 with the throttle open gently it really kangeroos...

Its a weber carb BTW, which was on there when I got the car

So far over the last few weeks I have checked or replaced the following

fuel filler neck is not rusty
Petrol tank is clean and clear
fuel filter replaced
fuel lines checked
carb has been off gaskets and rubber mount etc are fine
Vacuum pipes checked and some were replaced
air filter replaced
warm/cold air flap moves fine under vacuum
sparkplugs replaced
ht leads replace
dizzy cap / rotor arm replaced
dizzy vacuum thingy removed and checked
oil and filter changed (not that I thought it would be this!!)
I've played with fuel/air mixture (no difference)
I've played with ignition timing (no difference)

Alot of above I was doing anyhow, but this problem is bugging me and I dont really want to pay a garage to diagnose or sort it.. As I say on Idle and when accelerating is is smooth as can be..

Any other suggestions?

Thanks
Wilson

[dino]

My mk1 clipper has a weber carb the same as yours and i have got exaclty the same problem? So i hope someone can tell us what the problem is!

[wilson]

My mk1 clipper has a weber carb the same as yours and i have got exaclty the same problem? So i hope someone can tell us what the problem is!

Well... two days ago I bought a big bottle of redex for carbs, and rather than putting quarter bottle redex in full tank I put over half bottle redex in quarter of a tank of petrol...  I also poured the stuff directly into the carb aswell...  this seemed to make no difference..  however today it has seemed alot smoother...  still there but not as dramatic as usual, I'm gonna give it a couple of days and see what happens.  I also sprayed in the carb and all around with more carb cleaner again at the same time...

[dino]

OVER THE WEEKEND WE OPENED THE CARB UP AND CLEANED ALL THE FUEL INJECTORS AND RE-TUNED IT AND SO FAR IS HAS RUN WELL. MY MATE AT VW RESCUE THINKS THERE MAY A BLOCKAGE IN THE FUEL LINE SOMEWHERE , BUT AFTER THE WEEKEND WORK IT SEEMS TO BE RUNNING A LOT BETTER, ALSO RUNS BETTER WHEN THE TANK IS FULL OF FUEL.

WILL LET YOU KNOW ANYMORE NEWS

[wilson]

I'm going to have another look tonight, mine has been really bad today, I ran it low on fuel this morning, through laziness really, and the kangarooing has got real bad, unless I have my foot right to the floor!!  I swear the tank was clean when I looked in there...!

I'm gonna make a start now and make sure all is clean...  any tips on cleaning out fuel lines. pump carb etc etc??

Thanks
Marc

[wilson]

Finally I have found what could be my problem..  with the engine off I was playing with the throttle on the carb and noticed fuel leaking through the rubber mount under the weber carb...  after taking it off I cannot see an obvious split anywhere but I know it was getting through there...

Are these mounts specific for the weber carb or are they a standard item?  Where do I get them from and how much are they?

Thanks
Marc

[tomo320]

you can use standard mounts mate, the carb moves when you change the revs, if the carb gaskets knackered it will allow too much air in, say if you were on the motorway at a constant speed then you eased off for a roundabout would it die on you? what you have put sounds like carb-freezing but if the carb gaskets gone would be similar problems

[wilson]

you can use standard mounts mate,

Thanks, I'll try to source one tomorrow, couldn't see them on GSF site, but will give them a call in the morning...

if the carb gaskets knackered it will allow too much air in, say if you were on the motorway at a constant speed then you eased off for a roundabout would it die on you?

No, doesn't die on me, it never actually cuts right out...  but there was definatly fuel leaking out of the mount, so I would assume air could also get in!!

what you have put sounds like carb-freezing but if the carb gaskets gone would be similar problems

Yes it does, but I've checked the warm air flappy thing, and that certainly moves under vacuum, and the pipe is there to take the warm air from the exhaust manifold...   I'll get a new mount and if that does not solve anything then I will have another look at the flap see if its all working correctly

Thanks for the helpful comments
Marc