Would appreciate any advice on techniques for starting cold and on cold days.
I know the DRLA/IDF does not have a choke, but what is a good reliable starting technique when starting cold, particularly on cold days?
I have the hot/warm start technique down, is a part throttle turn key and engine fires and runs well. This is how I start my CV carb's motorcycles, and works well for the 912, but on a COLD start, I feel like I either flood the motor, or it doesn't get enough fuel and needs to be cranked A LOT............
It also seems to me as though the fuel drains back out of the lines and into the tank and the pump has to refill they lines. I understand this is a low pressure system and pump, but almost feels like I need a check valve.
I had a heck of a time getting it to start on Sunday, was 35 degrees, cranked quite a bit and didn't catch at all, smelled flooded, so I held pedal to the floor and cranked again, it eventually caught and started and other than having to feather the throttle till warm, ran fine....
So, other than 2 pumps, then hold throttle part open and crank, what is a good cold start technique?
Full Version: Carbs - Cold Weather Starting
Key on pump on 5 full gas pedal pumps then ignition. That usually works for me. If it doesn't fire first time then pump on and 2 more pedal pumps then ignition. That's good down to mid 30's. Any colder it stays in the garage.
The problem you describe sounds more like a timing or not hot enough spark issue.
As far as fuel drain back goes, there is more than enough gas in your carb float bowls to get you going.
Some peeps have a different number for the pedal pumps but it's all basically the same method.
I pump 3 times, then try it without any gas. If it doesn't catch first time I give a couple more then again foot off the gas.
The closed throttle plate acts like a choke.
Once it fires you start feathering in the gas to keep it running, Then it is best to warm up the engine (city with stop lights) or drive slowly (rural) for the first few minutes, this is mostly do to crappy idle till warm.
Below freezing issues: the IDF is susceptible to freezing linkage/shafts if water gets on the carb and freezing during operation if the manifold isn't picking up any heat from the manifold/head. I drove for years with morning temps in the mid-teens, with DCNF webers.
As far as fuel drain back goes, there is more than enough gas in your carb float bowls to get you going.
Some peeps have a different number for the pedal pumps but it's all basically the same method.
I pump 3 times, then try it without any gas. If it doesn't catch first time I give a couple more then again foot off the gas.
The closed throttle plate acts like a choke.
Once it fires you start feathering in the gas to keep it running, Then it is best to warm up the engine (city with stop lights) or drive slowly (rural) for the first few minutes, this is mostly do to crappy idle till warm.
Below freezing issues: the IDF is susceptible to freezing linkage/shafts if water gets on the carb and freezing during operation if the manifold isn't picking up any heat from the manifold/head. I drove for years with morning temps in the mid-teens, with DCNF webers.
QUOTE(bandjoey @ Nov 18 2015, 02:14 AM) 
Key on pump on 5 full gas pedal pumps then ignition. That usually works for me. If it doesn't fire first time then pump on and 2 more pedal pumps then ignition. That's good down to mid 30's. Any colder it stays in the garage.
on our modified 2L with dellorto DRLA40s--using exactly the same procedure as above--it's worked for 30+ years
warm start is turn key with throttle closed, no pedal pumps (push throttle to half-way if required).
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