Reply To: Zenith 24T2

[sidevalve5]

An update, the adjustable tapered screw does work very well with Zenith 24T2 carb that has a fixed jet. The Jap 6 in my newly acquired Trusty was obviously running rich. Had to take the head a barrel off as part of the re-commissioning and there was a lot of sooty type deposits. It was not hard baked on carbon, which I would have expected if it was burning oil. I set the fuel/air mixture with a plug chop and after a couple of efforts with doing adjustments, I have the plug with the correct brown coloured deposits on the end. The engine sounded beautiful and pick up from tickover was smooth. But currently only scuffling with 7” diamond feet on 5 legs, with at 2” deep in ground I have already gone over both ways with ducks feet at 3” in clay soil that was padded down well. So did not need much power on the already roughed up ground. Find when I put a SV engine to harder work and if I have the correct brown colour on the plug, I get a bit of a hunting type misfire. A tweak to richen the mixture usually cures it, even though the plug colour changes more to a charcoal shade.

The Zenith carb on the Jap 5 was taken off a Trusty that must have been left outside uncovered for decades. It had thick corrosion deposits inside and out, could clean off what I could and blew everything through with an airline. Have also recently had it ultrasonically cleaned. But the air mixture screw makes no difference to the tickover, unlike to carb on the Jap 6. Where I could adjust both main and idler jets. I think that the blind holes and passageways still have corrosion deposits in them and was thinking of soaking it in something like drain cleaner or caustic soda. Would be interested if anybody has any advice as to what is the best solution.