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Engine turning while towing

Posted: Fri Apr 14, 2017 9:54 pm
by rowdy1
Anyone ever seen an aircraft engine turning over while towing? I was running south on I-75 between Gainesville and Ocala this morning in the hammer lane around 80mph and came up on an airboat with a straight valve 540, with a 6 blade warp drive. The prop was turning about a quarter turn at a time. I backed off and followed him for about 15 miles, it must have made 25 - 30 revolutions. That cant be good for the motor. BTW I looked very close, no gearbox or anything out of the ordinary, and all of the plugs and wires were on it. That thing must have been worn out.

Re: Engine turning while towing

Posted: Sat Apr 15, 2017 9:14 pm
by Huntingwithahoyt
Hmmmm....that's weird....I have a 520 continental and there's no way mine could do that....heck its hard to turn by hand.....of course mine is not worn out though....

Re: Engine turning while towing

Posted: Sun Apr 16, 2017 4:35 am
by Sarahj
Was the boat named blow by? 90hp 0-540 sponsored by aeroshell? :lol:

Re: Engine turning while towing

Posted: Sun Apr 16, 2017 8:18 am
by twister69z
Had a A-65 continental that would start by itself if I forgot to turn the mags off.

Re: Engine turning while towing

Posted: Sun Apr 16, 2017 8:54 am
by Scarecrow
Twister; you being an ace mechanic I wouldn't be telling that story. LOL

Re: Engine turning while towing

Posted: Sun Apr 16, 2017 9:01 am
by SWAMPHUNTER45
Not being an Aircraft guy I was thinking about that possibility of it firing off if the mags were left on.

I could see it happening

Re: Engine turning while towing

Posted: Sun Apr 16, 2017 9:32 am
by HAMMERHEAD
Guys my race boat with over 300 PSI cranking pressure will turn a little when pulling long distance. Our supercharged boat would turn a revolution about every mile. If you turn the motor very slowly the compression will bleed off, it's not a big deal!

Re: Engine turning while towing

Posted: Sun Apr 16, 2017 9:33 am
by HAMMERHEAD
Scarecrow wrote:Twister; you being an ace mechanic I wouldn't be telling that story. LOL

Sounds to me like a well tuned motor! Good job Twister!

Re: Engine turning while towing

Posted: Mon Apr 17, 2017 9:08 am
by John Fenner
Not uncommon to windmill, no harm in it, proper rotation, pre oiling for cold starting. My cousin would sneak over to a buddy's 65 Continental and kick the mags on when he wasn't looking, boat would be idling when he got to the ramp, funny wtf moment.

Re: Engine turning while towing

Posted: Mon Apr 17, 2017 9:36 am
by digginfool
I've seen it happen to AC boats going down the highway; same thing, about a 1/4 turn every so often.