Suffolk Punch 43s Throttle not working

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norbet75
KG Regular
Posts: 2
Joined: Wed Aug 31, 2016 11:07 am

Hi all, seems this is the place where the knowledge resides on such matters. I've acquired a 43s with the Dellorto FHC carb. When I recently purchased it, it ran quite fast albeit lumpy and hunted (revs varying). So I set about disassembly of the dellorto carb and discovered deposits in the float bowl. Gave it a thorough clean up including the central jet and put it all back together. Cleaned out the fuel tank, replaced with fresh fuel and gave it a whirl.
Now it starts on full choke/half choke but cuts out once choke is taken off. Messing about with the idle screw and mix screw I can just about get it to idle, albeit still lumpy.
The problem I have is the throttle cable, when moved, it seems to have no effect on the carb and doesn't increase the revs. It's linked to a bar below that moves up and down and when fully lowered connects to a kill switch which works just fine. On the other side of this bar/linkage there's a long link with a plastic top to it with a spring connected to the same bar as the throttle cable. Problem is, when the bar moves this long link/spring does not.
I suspect I may have reassembled incorrectly, but to be honest I never checked it before taking to bits. In my haste I just jumped on in with the carb cleaner when I should have studied it more beforehand. :oops: There's also a nagging fear I may have lost a spring or linkage or something!
I cannot find any diagrams on line other than expanded views of the mower itself and not the engine/carb/throttle bits.
I did find a thread called "no throttle action" but despite best efforts to describe the fix I can't seem to work out how this throttle should work.
Any ideas>?
Richard
KG Regular
Posts: 71
Joined: Mon May 08, 2006 8:37 pm
Location: Lancaster

Here are a couple of parts drawings from the Qualcast B66 rotavator parts book, this used the same A114 engine and DelOrto carburettor, note that there is a hair-pin spring (item 13) on the throttle butterfly.
Attachments
DelOrto.jpg
DelOrto.jpg (62.36 KiB) Viewed 4064 times
B66 links.jpg
B66 links.jpg (91 KiB) Viewed 4064 times
norbet75
KG Regular
Posts: 2
Joined: Wed Aug 31, 2016 11:07 am

Thanks so much Richard. I think this will help.
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