Hi team,
I've just built up a victa 160 carburetta from several old units I've had lying around together with some new parts and I cannot get the engine to run less than wide throttle position. The engine spark is strong and timing is spot on. I can get the engine to run on full throttle OK but the moment I back off the throttle a little it stalls. The cut-out mechanism in the carby is not causing the fault as proven with multimeter. I've done the foillowing work on the carby:
1. Replaced inlet manifold O-rings (block o-ring and carby o-ring)
2. Stripped, cleaned and blew out the carby body.
3. Blew out the main jet.
4. Replaced the inlet needle
5. Checked the float - OK
6. Removed the top cover and large spring - all OK
7. Removed and checked diaphragn - OK
8. Removed and checked the bottom small spring - seems OK
9. Removed the spider and checked it - seems OK
10. Removed the cam and checked it - seems OK.
11. Replaced the throttle cable - The original one was a bit sticky.
12. Re-assembled the carby and started engine but stalled when throttle was moved off maximum throttle opening.
13. Repeated the above exercise at least 5-times using different bits from different carbys but same result.
About the only thing I haven't tried is changing the de-conpressor???
I honed the cylinder and fitted new rings. I also fitted new bearings and seals so i am resonably certain that the crank case is leak tight and that the head gasket is holding..
Can anyone out there offer any ideas as to why I cannot get the damn engine to idle or at least operate at less than wide open throttle??? ...... It appears to me that the angle moulded into the cam is mis-matched to the spider or to the poppet valve that is actuated by the spider as it falls down the incline of the cam? I guess what I'm asking is ... "Are all parts in the plastic carburetta that have been manufactured over the years interchangeable with one another" and can you offer any other fault diagnostics?
