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Scorching heat in NW cause trouble with engine starts?

Bought aircraft in January and follow start engine checklist to the T. As the ambient air temps have been scorching in Montana this summer, I find the engine needing three to four times as long engaging the starter to get it going, sometimes have to stop cranking and wait a few minutes before engaging again. I have not changed the sequence on my start checklist one bit. Is this strictly due to high outside air temps? If so, what do you pilots in AZ do in the summer to get better or easier starts? If not, any suggestions? KMSO elevation 3200 feet, density altitudes routinely between 5000-6000 feet this summer. One day with humidity it was 8900 feet!!

Model: Bonanza A36TC
Aircraft Serial Number: E-522
Posted 7/20/2021 - 3 months ago
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Could be the engine is talking to you. Fuel injection set up, ignition needing attention, things like that.

This past spring, or even in winter after you adopted her, how were the hot starts?

Mike
ABS Tech Advisor

Posted 7/20/2021 - 3 months ago
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Hot starts have not been a problem. So when you say ignition are you referring to timing or mags? Thank you for your response. I'm assuming by the lack of posts from super hot places that the ambient air temperature does little to affect the start of the engine.

Rich

Posted 7/23/2021 - 2 months ago
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I have not been a believer in the hot start method published by Beech/Continental. If the engine is properly set up per the former SID97-3 (any version) or current Manual M-O, the best method I have found is to slightly advance throttle and put mixture full in. Start cranking, and give a 1 second or so shot of boost pump. The engine should start with just a few blades. If it does, great. If it starts to stumble, give it another quick shot of boost pump. If this does not do it, do a flooded start (which I believe is what you are now doing). Mixture up, throttle up and about 2 or so seconds of boost pump. Then boost pump off, mixture lean and full throttle. Start cranking as you are now doing. It will take numerous blades to "clear" the engine. When it does start, be ready to pull throttle back as the engine accelerates and then push mixture to full rich.

Posted 7/23/2021 - 2 months ago
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In reply to: Rich Sellman | 7/23/2021 - 2 months ago

Hot starts have not been a problem. So when you say ignition are you referring to timing or mags? Thank you for your response. I'm assuming by the lack of posts from super hot places that the ambient air temperature does little to affect the start of the engine.

Rich

To the ignition question: Yes. 500-hr inspections of the mags, proper mag timing, ignition harness checks, spark plug servicing and testing (bomb, as well as resistance).

You might also try varying the amount of prime.

Posted 7/23/2021 - 2 months ago
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One item often overlooked (see above list for example) is the ignition vibrator for Shower of Sparks systems. The health and proper function of this small box has a significant impact on starts, especially the hot variety. One must not just observe that a spark is being produced, but verify using the simple setup in the overhaul manual that desired current (work) is met.

If you have this system you may see from your logs that it has been decades since any maintenance has been performed to keep it healthy and its owners happy.

Posted 7/24/2021 - 2 months ago
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Thank you Donald and Micheal,
Will address it with my AP.

Posted 7/29/2021 - 2 months ago
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Scorching heat in NW cause trouble with engine starts?