Icing up -Twin solex on 1800 Kombi

GTMac · 10 Aug 2006, 7:34 pm

If one of the carbies is icing up around the intake area what does that mean?

Bizarre · 10 Aug 2006, 8:01 pm

The fuel vapour is turning back into a liquid

Heat is being absorbed as there is a change in state from a gas to a liquid.

Unusual in a twin carb - runners are too short.

Not uncommon on centre mount carbs where the manifold is long and not enough heat from the heat risers

Menangler · 10 Aug 2006, 9:02 pm

Are you running a stock air cleaner? or a Donaldson one

GTMac · 10 Aug 2006, 9:32 pm

Menangler wrote:Are you running a stock air cleaner? or a Donaldson one

Just stock.

aggri1 · 11 Aug 2006, 7:58 am

That's odd, I've never had a problem even on very cold mornings (on a stock 1800 too). Are you sure that it's doing that? What makes you believe it's icing up?

GTMac · 11 Aug 2006, 12:43 pm

aggri1 wrote:That's odd, I've never had a problem even on very cold mornings (on a stock 1800 too). Are you sure that it's doing that? What makes you believe it's icing up?

Simple...........when I open engine compartment you can see the ice forming like morning dew on the manifold.

Bizarre · 11 Aug 2006, 1:29 pm

Any chance of a vac leak there some where???

aggri1 · 11 Aug 2006, 1:43 pm

GTMac wrote:
aggri1 wrote:That's odd, I've never had a problem even on very cold mornings (on a stock 1800 too). Are you sure that it's doing that? What makes you believe it's icing up?
Simple...........when I open engine compartment you can see the ice forming like morning dew on the manifold.

Wow, actual ice! I take it the air's pretty humid then... Still makes me wonder why it's that bad though, I've never seen ice, just condensation.

When were the throttles last balanced? Or the idle circuits for that matter? If it's sucking harder and therefore expanding the air more on one side than the other, then that would result in a greater temperature decrease. I imagine that if the throttles weren't opening the same amount, then this might happen...

[ Edited on 11-8-06 by aggri1 ]

Bizarre · 11 Aug 2006, 3:06 pm

Hmmmm.... what about the bushings in the rod in the linkage.
They get shot and the carbs could be opening all over the place.

Just a thought

GTMac · 11 Aug 2006, 6:28 pm

Bizarre wrote:Hmmmm.... what about the bushings in the rod in the linkage.
They get shot and the carbs could be opening all over the place.

Just a thought

There is slight play in the butterfly shaft but I didnt realise such a small amount of movement would effect the air mixture etc. so much. Forget about when its cold, its a nightmare but when at normal operating temps, when you release foot to change gears you cant ease back on the pedal, you have to flaten it or it will hesitate and splutter.

kombidaze · 11 Aug 2006, 10:24 pm

if my motor was performing like yours i would do and or check the following
rebuild the carbies, including rebushing throttle shafts if badly worn, with rebuild kit about $60 - $70 covers both carbies check the float level and make sure the accelerator pumps are working correctly also the inlet manifolds for leaks at the heads and check all vacuum hoses for cracks and they should all be clamped up, also check the solenoid shut off valves on sides of carbies if they don't work the idle suffers badly also replace the plugs and points is the coil in good shape and are the plug leads ok? check the timing and do the tappet clearances.
a bit of a list but try one thing at a time and see if it improves.