Hi, what a fantastic resource this forum is.
I'm restoring a deceased estate SB45 from about 1973 (restoring as in getting it running nice and selling it!). Its has a Kirby/Tecumseh HK30 H4-5A W3 engine and it hadn’t been run for 20 years. I cleaned it up with lots of degreaser and WD40. Drained and replaced oil with Classic Light engine oil. Oiled chains and shafts with 80-140 vintage gear oil. Replaced foam air cleaner with new one. Cleaned fuel tank with Evaporust. Cleaned carburettor with Repco Carby Cleaner. Replaced carburettor rubber primer with working original second-hand unit. Replaced muffler with an almost new original. Replaced NGK B6S spark plug. Cables and other small parts lubricated with Inox. The compression seemed very good, and measured 110PSI with my old compression gauge. The clutch was professionally rebuilt after a tragic discovery, and the blades sharpened.
It started first half-pull after 20 years. Initially idling perfectly but running a little rough, then improved and seemed to improve even more when the engine was under load. It idled pretty well but runs rough and smoked with the throttle open. It ran better with the air cleaner off so I checked the main jet and dropped the float level; it ran pretty well, but still lumpy. It starts at idle with barely a pull on the starter.
I tried the governor spring in a couple of different holes but it ran worse. The governor spring looks pretty misshapen, So I was thinking of trying a new one, but doesn't that extra tension mean even more throttle opening? At 1/2 throttle its ok but at 3/4 throttle the governor seems to take over and open wide.
Pretty hard to describe in text. Does anybody have some suggestions?
Thanks.
