jlanglois

I was in the process of breaking in my Norvel .40 and something I've never had happen before, happened! The prop shaft was unthreading from the actual motor during starting, and after I re tightened it, same thing happened again a few minutes later. Its quite nerve racking. Should I just put some Loctite on it and move on?

downunder

I've pretty much finished running in my Norvel 40 too But the the first thing I always have to ask whenever someone is having a problem keeping the prop tight is are you using a spinner with a plastic backplate? They don't usually have enough friction to stop the prop from slipping when starting and that loosens the prop nut.

jlanglois

Well its not so much the prop nut as the actual shaft coming out of the engine. Now is there a way to keep my spinner from slipping or is it the nature of the beast, so to speak.

brett65

My Feedback: (18)

Sounds dangerous, I would try to contact the manufacturer. If not, use red threadlocker on it, its practically permanent.

ChuckW

I've had a couple Norvel .40's but never seen that happen. Make sure you are getting the prop nut good and tight. Don't worry, it is hardened steel and will take a lot of torque.

You can also use a little blue Loktite to hold the stud into the crankshaft.

downunder

If the prop comes loose when starting then it's a lack of friction somewhere. A hard plastic prop like an APC has very little friction against a plastic backplate surface for instance. Something has to give and in your case it's the prop stud instead of the more usual nut. The prop stud like the Norvel uses is an excellent idea and all engines should have that instead of the usual one piece crankshaft because in a crash the stud breaks instead of the crankshaft. Some other engines also use that system, some K&B's, Taipan etc. If you take out the stud you'll see there's a different length thread at each end. This is to allow for prop hub thickness from fine pitch to coarse pitch props so if you locktite it in place you're likely to lose that benefit and if the stud breaks you may not be able to get it out. Also, if you locktite it then you'll still have the problem of the prop coming loose but then it'll be the nut. I really like the captive prop washer on the nut too and I don't know of any other engine using that.

jlanglois

well im using a wooden prop so its on tight.. Ill try blue loctite before going to the more permanent red and see what happens!

flyinrog

My Feedback: (1)

They went out of business a couple of years ago,,,actually they "moved" with the promise of returning, but it never happened, they were making the engines in a munitions factory in its off time, now they cant find anyplace to make them, thats the last I heard..Rog
I have norvel .049's ,.061's and .074's and a .15