Anybody know what these are like when starting from cold? Thinking of getting a twin set up but, not sure whether to get electric chokes or not.
Unfortunately, mine are not always as reliable as MorkC68's seems to be. They are a bit temperamental on cold damp morning's.
^^ same for mine, sometimes takes two goes as I'm still getting used to how they work as only fitted over the summer. Sent from my Pixel 5 using Tapatalk
Yes very true, once warm they're great and real easy to work on. I just need to figure out my starting technique...a bit like me as I get old I take longer to start!
Only time I have an issue is like sub zero temps but Allways starts just don't rev it leave for 30 seconds ur away Sent from my iPhone using Tapatalk
No chokes, it SHOULD be hard to start cold. If it's easy it's likely your idle jets are too big. You have two choices: Easy start but too rich when it's warmed up. Hard to start and correct when it's warmed up. If I put tiny 45 idles in mine it won't start at all in the winter though it runs great warmed up. So I upped them until it would start. This year, with @snotty 's encouragement I drilled holes in my carbs and now can run bigger idles without being too rich. Result! It starts easier too.
I think the answer is, because we live in a sometimes cool area of the world, having automatic temperature driven chokes beats not having chokes. Even in these days of ECUs ALL engines have cold mixture enrichment at startup to deal with petrol not evaporating as well when cold.. Its the Californian VW owners who decided they were a bad idea because the air going in was always fairly warm. And because if you raided the carburettors off a water cooled car there was no hot coolant water to work the chokes. I was messing around the other morning with the electrics, left the ignition on for 30 mins (have accuspark ignition no risk of cooking the coil), and the leaner running mixture settings on my choke-equipped progressive made it almost impossible to start. And then it wouldnt idle and it died if you opened the throttle so it chugged at 500 rpm for a bit until it caught, then ran badly. Let the choke cool down and tried again, started easily.
Two or three pumps on the accelerator and starts no problem won’t rev up though for a few seconds but fine when it warms up a bit. Very much like me on a cold morning Some of us remember the cold wet morning start up routine pre fuel injection times & wondering whether it’s going to start or not & am I going to be in the bus queue again
Plus points are easy to fit & set up also cost effective replacement for the originals if you’re originals are worn and beyond repair. Bad points are not great at cold starting also idle can be a bit erratic usually improved with a balance pipe. If you can run to the cost a set of twin 40s are the way to go but double the cost of a 34ict set up. Whichever you go for they are better than a single progressive.
Interesting thought, do you have pictures of your hole! .......seriously, I'd be interested in knowing more about that mod My idle jets are 55s. I wonder what @Gooders, @grandmst, @1973daisey and @MorkC68 have as their idles?
Love to see such commonality Idle 55, Main jet 155, Air 175, Needle 175, Pump inlet valve 40, Emulsion F6 Standard type 4, 2ltr (converted by po from FI)
I’ve been running that jetting for a while and it works However now i have fitted an air fuel meter it does show it running quite rich all through. So i am trying a few different jet options to see if i can improve it a bit. With 150 mains 170 airs its in the low 14:1 area cruising at 50-55mph. The general consensus however is that aircooled engines prefer to run slightly rich so i am going to revert to 155 main and go up 1 on the air to a 180 then see where it’s at
