Pat Stewart
Well Known Member
I have a 7A with an YIO360M1B. If this thing runs for just 10 minutes it will require a hot start to get it running. I am interested in what others have done to prevent this issue and or your hot start procedure.
I have the exact same engine, and I go all in. The only way I can hot start this engine without backfiring it is by flooding it, and it works every time.
- With throttle wide open and mixture max rich (both levers full forward), I run the boost pump for 6 seconds.
- Keep the throttle wide open, but pull mixture full back to lean cutoff.
- Now, crank the engine. Be mindful of the starter's run time limit, but after about 8-9 seconds the engine will try to catch. It'll spit and fit, but in a few seconds the fuel/air mixture will balance and she'll try to roar to life.
- with both hands, swap the throttle and mixture positions: Pull the throttle back to about 1/2 inch open while advancing the mixture to rich. That takes her back down to normal ops.
- don't forget to turn the alternator on.
This is the only way I ever hot-start my hot engine. I have not had a single backfire since.
If you've shut down the engine using the mixture control, what is the source of the fuel if you use the hot start procedure...?
J
The volume of fuel beyond the distribution unit is open to the intake manifold though the injector. It will boil and discharge via the injectors. Not sure what pressure resistance the spider adds, but it also may spill some of its fuel due to expansion.
Refilling this volume is what the 1 sec (or less) boost pump on-time is for.