30 pic/2 carb
- Thread starter robins
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noddy
Well-known member
hard to say
the adjustment procedure for a 30 pict 2 is:
1. get engine up to temperature 50 to 70 C
2. check the choke butterfly is fully open.
3. Adjust idle speed using the screw on the throttle arm till idle speed is between 800 to 900 rpm.
4. Turn the mixture screw in the side of the carb body in until the engine begins to slow, from this position turn the mixture screw out till highest idle is archived.
5. If idle is out of the range shown in 1, adjust using the screw on the throttle arm to achieve an idle of between 800 and 900 rpm.
remember on these carb the only mixture you can change is the tick over mixture, running mixture is set by the jets.
Hope this help.
Ian
the adjustment procedure for a 30 pict 2 is:
1. get engine up to temperature 50 to 70 C
2. check the choke butterfly is fully open.
3. Adjust idle speed using the screw on the throttle arm till idle speed is between 800 to 900 rpm.
4. Turn the mixture screw in the side of the carb body in until the engine begins to slow, from this position turn the mixture screw out till highest idle is archived.
5. If idle is out of the range shown in 1, adjust using the screw on the throttle arm to achieve an idle of between 800 and 900 rpm.
remember on these carb the only mixture you can change is the tick over mixture, running mixture is set by the jets.
Hope this help.
Ian
noddy
Well-known member
How was the mixture checked?
Was it only at tick over?
Best way to check running mix is to run van along a quite road till engine is up to running temperature. Then whilst going along turn engine off and coast to a stop, (dont let engine go on to tick over when doing this), then take one or more plugs out and check colour of central insulation if it grey to light brown, mix is ok, if its black and carbon fouled then the running mixture is too rich.
My guess would be that your tick over mixture is set too rich, its highly unlikely that the jets are worn out inside the carb, from what Ive read I think you would need to run a carb for about 100 years to wear the jets out. (unless some one has pushed wire through the jets to clear them, big no no).
The best route if the running mixture is too rich is to buy a new set of jets and strip the carb and replace, much cheaper option than a new carb.
The only other things to check that can cause a rich running mixture are:
That the fuel pump rod is at the correct height, if the rod is too long will deliver fuel at too higher pressure for the float valve in the carb to keep closed, this will cause a constant fuel dump in to the manifold and rich running mix.
Take fuel pump of engine, leave plastic rod guide in place turn engine over by hand until the rod is at its highest stroke then measure from top of plastic rod guide including any gasket, to top of rod, it should measure 13mm, if not put extra gasket/s in, till it measure 13mm.
The only other thing to check if every thing else checks out, is that the float chamber valve is not stuck open so there is a constant flow of fuel in to the carb this will cause the same problem as above. (not sure of the best way to check this).
Was it only at tick over?
Best way to check running mix is to run van along a quite road till engine is up to running temperature. Then whilst going along turn engine off and coast to a stop, (dont let engine go on to tick over when doing this), then take one or more plugs out and check colour of central insulation if it grey to light brown, mix is ok, if its black and carbon fouled then the running mixture is too rich.
My guess would be that your tick over mixture is set too rich, its highly unlikely that the jets are worn out inside the carb, from what Ive read I think you would need to run a carb for about 100 years to wear the jets out. (unless some one has pushed wire through the jets to clear them, big no no).
The best route if the running mixture is too rich is to buy a new set of jets and strip the carb and replace, much cheaper option than a new carb.
The only other things to check that can cause a rich running mixture are:
That the fuel pump rod is at the correct height, if the rod is too long will deliver fuel at too higher pressure for the float valve in the carb to keep closed, this will cause a constant fuel dump in to the manifold and rich running mix.
Take fuel pump of engine, leave plastic rod guide in place turn engine over by hand until the rod is at its highest stroke then measure from top of plastic rod guide including any gasket, to top of rod, it should measure 13mm, if not put extra gasket/s in, till it measure 13mm.
The only other thing to check if every thing else checks out, is that the float chamber valve is not stuck open so there is a constant flow of fuel in to the carb this will cause the same problem as above. (not sure of the best way to check this).
