EricJ Posted October 6 Report Posted October 6 Two things to try that work for me depending on the situation: Prime like a cold start, but for about 1/2 the normal time. Then start like a cold start. This is usually what I do. Whatever you're doing, once it starts turn the boost pump on. If the problem is that the mechanical fuel pump is hot and cavitating, the boost pump will add input pressure and reduce the likelihood of cavitation (vapor lock). I do this at high DA or when it otherwise seems to have trouble starting.
DCarlton Posted October 6 Report Posted October 6 13 hours ago, Tiny18Driver said: Thanks everyone for the discussion. I went back and looked at the video again and keyed-in on the fact that the Lycoming basically floods itself after shutdown. So in my case, if I pushed the mixture forward too quickly (don’t remember if I did or not), the motor didn’t fully light-off because it re-flooded. If that is indeed true, my previous “Plan B” to do a normal start 2nd, because I’m assuming the cylinders are ‘dry,’ actually exacerbates the problem since the cylinders are actually crazy flooded by that point. So now my question becomes: is there some sort of a rule-of-thumb anyone uses in choosing between boosting first (as in a normal cold start), or a hot start after the plane has sat for a period of time after a flight (e.g. out-&-back). I understand a hot motor and an obviously cold motor, is there some clue as to whether there’s still fuel / vapor in the fuel lines and the cylinders, or if it’s all evaporated out of a ‘warm’ motor? I parked my plane a couple of days ago after a 40 minute flight, had a "$100 Cobb Salad", walked around the airport and looked at my buddies RV project, had the discussion all over again about whether to use a hot or cold start procedure, then climbed in the plane and attempted the hot start procedure. It fired but stalled on the first attempt; I may have advanced the throttle too fast; I usually do. I tried again and it started right up. I was on the ground between 1-2 hours. I don't think you can go wrong by trying the hot start procedure first. 2
MikeOH Posted October 6 Report Posted October 6 3 hours ago, Shadrach said: Not necessarily. If the engine fires but doesn’t start (hot or cold) a shot of prime will facilitate easier starting on the next attempt. Thanks for that tip. I'll keep it in mind but, so far, I've not had that issue (thankfully!). My usual stunt is impatience and I advance the mixture too rapidly and get too much fuel. 1
Shadrach Posted October 6 Report Posted October 6 On 10/6/2025 at 9:41 AM, Paul Thomas said: I suspect you can picture that in your mind and see how the fuel travels through the system enabling you to think through what needs to be done. Some people do not have that capability and it's not a knock on them; people process information differently. Some people need to rely on the if/then logic and need to follow the checklist. I get it, it's the difference between cooking and using a recipe. A recipe is all we have initially. However, over time it's a good idea to learn how to make the dish and what makes it work. Knowing the granular details behind the task at hand not only makes for more effective performance of the task, it will also help identify when there's a secondary issue causing a problem, so that one doesn't sit there throwing fuel on an ignition problem just because the symptoms seem the same. If I had experienced an in-flight engine failure in my first several years of flying, I would have gone straight to the checklist. Now it's likely that the checklist would be my last step to ensure that I didn't miss anything while actually trouble shooting the problem rather than performing the rote...Mags on...check...Fuel selector both...check...Mixture rich...check. 1
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