Jeffds1360 Posted February 25, 2021 Report Share Posted February 25, 2021 Do they wear? Even when well adjusted mine will not give throttle until choke is well open. I'd like to choke off but a bit extra throttle until fully warm. Got a mind to file mine off, adjust back and get throttle before ckoke comes up. (CD150) Link to comment Share on other sites More sharing options...
johny Posted February 25, 2021 Report Share Posted February 25, 2021 Youve got the adjusting screw that is pushed by the cam which you can set to be gnats clear of the cam with choke off but I take it even then by the time you get more revs theres too much choke? I seem to remember old Alfas actually had an adjustable tickover lever so, independantly of choke, you could raise the revs which was useful at high engine temperatures😁 In your case I think the cam is flat at the beginning so really you need to add metal to operate the throttle earlier or face drastically changing its profile.... What is the normal tickover speed as maybe this could be raised a bit? Also is your mixture on the rich side as then youll need less choke to start which wont give enough revs? Link to comment Share on other sites More sharing options...
Jeffds1360 Posted February 25, 2021 Author Report Share Posted February 25, 2021 Thanks once again for the input Johny, I'm so bored I've fitted a cushion on the o/s front wheel and am camping on it most days playing with tickover, timing, mixture and choke to get best out of her. I think the cam has flattened just past off. I'm going to take a bit off the top and shape it to be more aggressive with the throttle before the choke comes in, therefore having to screw the screw further out. I'm getting there. Bloody thing ends up a mil or 2 out after every test drive...don't you love these beasts!! Link to comment Share on other sites More sharing options...
daverclasper Posted March 1, 2021 Report Share Posted March 1, 2021 On 25/02/2021 at 18:15, johny said: In your case I think the cam is flat at the beginning so really you need to add metal to operate the throttle earlier or face drastically changing its profile.... I reprofiled mine for Strombergs. Took it off the upper area. I think, as you can then adjust the screw to get the lower/first area of contact, then it's doing a similar thing?. It improved mine. Link to comment Share on other sites More sharing options...
Jeffds1360 Posted March 1, 2021 Author Report Share Posted March 1, 2021 Mine too Dave, trim the top back and just screw out to contact. Worked fine on mine Link to comment Share on other sites More sharing options...
Iain T Posted March 1, 2021 Report Share Posted March 1, 2021 I have a new choke mechanism from Burlen which includes the cam on my 150CDS. I assume the profile is correct, I have the screw about 1.5mm away from the cam. An more and it over fuels and revs don't rise if I pull the lever out fully. It's a fine balance as the cam operates the choke enrichment discs and opens the butterfly's. Link to comment Share on other sites More sharing options...
Jeffds1360 Posted March 1, 2021 Author Report Share Posted March 1, 2021 don't pull it out fully! I prefer a few revs at 1/4, a bit choke at 1/3 and cold start at 1/2. Only freezing cold would I even contemplate full choke, with a very cold engine too. My screw is touching/.005 thou. Link to comment Share on other sites More sharing options...
Gully Posted March 2, 2021 Report Share Posted March 2, 2021 18 hours ago, Jeffds1360 said: don't pull it out fully! I prefer a few revs at 1/4, a bit choke at 1/3 and cold start at 1/2. Only freezing cold would I even contemplate full choke, with a very cold engine too. My screw is touching/.005 thou. I think every engine has its vagaries! Mine likes full choke to initially fire in all weathers (which it does pretty much immediately), but as soon as it fires I reduce the choke to a third, then reduce accordingly as the engine warms and will tick over without the slightly elevated RPM. The workshop manual specifies one sixteenth of an inch separation between the fast idle screw and cam. Gully Link to comment Share on other sites More sharing options...
Iain T Posted March 2, 2021 Report Share Posted March 2, 2021 49 minutes ago, Gully said: think every engine has its vagaries! Very true, get the screw adjustment wrong for your engine and you can be tugging on the starter for ages. I still think mine has just too much clearance. Link to comment Share on other sites More sharing options...
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