Spinner question
 

Ok, I'm pretty new at this stuff and need help here. I have a Saito FA-56 and a Du-Bro
7mm x 1 spinner. I must have the wrong spinner because, when I put on the prop and then the nut and then the lock nut and then the spinner, the spinner is like a 1/2 away fron the prop and looks really dumb. Where did I go wrong?
Thanks

RE: Spinner question
 

The spinner should have come with a "back plate". You put the back plate on first, then the prop, then the prop nut, then the spinner. does this help?

RE: Spinner question
 

Maybe I have read this incorrecly, but it sounds like you are assembling the pieces in the wrong order. Remove everything from the crankshaft except the thrust washer. Put the back plate that came with the spinner on first, seated against the thrust washer. Slide your prop on next, followed by the prop washer, then whatever nut or nuts came with the engine. Not sure how your particular spinner attaches to the back plate, but if you do the above, aligning the prop to accept the spinner and attaching the spinner to the back plate will be apparent.

RE: Spinner question
 

Their is no back plate with this spinner. I know what you mean, but this is just an aluinum spinner and thats it.

RE: Spinner question
 

You said in your original post that this was a 7MM X 1 spinner. I missed that. Is it threaded? This may be a prop nut rather than a traditional spinner. If it is threaded directly onto the crankshaft, it is used in place of the prop nut(s) that came with the engine. Since most four strokers I have seen use a locking nut configuration of some kind, I don't know if an aluminum prop nut is a good idea. Maybe some of the other guys have used then with four cycle engines and can better advise you.

RE: Spinner question
 

Yeah, that mix probably does look a bit silly. Most prop nuts, or spinner nuts, I've seen are really designed to replace the nut on a 2 stroke engine. They should not be used to replace the nut/lock nut combination on a four stroke. The double nut setup is there for safety becasue a backfire on a 4S can eject the prop. Double nut greatly reduces the risk the prop will leave the shaft. You did the right thing by keeping the double nuts, but then any spinner nut will look silly at the end of all that. Your best bet to improve looks is to use a spinner (cone and backplate.) Cheers

RE: Spinner question
 

What spinner would you guys recommend for this motor?
Thanks

RE: Spinner question
 

What plane is it going on?

It's the plane that designates the spinner, not the engine.

RE: Spinner question
 

Its a World Models J3 .48 Cub

RE: Spinner question
 

In that case, you don't want a spinner, you want what you have, which is a "Hub Nut" or "Spinner Hub"

Use it in place of your prop nut - So you will have the prop, followed by the Thrust Washer, then the Hub.

RE: Spinner question
 

Thats fine with me, but I was also told with a 4 stroke you need a lock washer.

RE: Spinner question
 

Hi!
I personaly never use a lock washer on my fourstrokes, works just fine without them. Just tighten hard with a spanner and never run the engine lean.


Regards!
Jan K
Sweden

RE: Spinner question
 

From the sound of it, you have a Dubro prop nut. Prop nuts are not just for 2-strokes. Just use the prop nut in place of the nut and lock nut that came with the engine. Get it good and tight. If you are using an electric starter to spin the engine you don't have to worry about backfire. I use DuBro prop nuts on most of my engines up to Saito 1.8 without any problems.

Rich

---------------------------------

Wyoming Wind Festival Jan 1 to Dec 31

RE: Spinner question
 

Exactly
I use prop nuts on several four strokes, and have never had a problem. Just don't be scared to get it tight. It has to be real tight, but I've never had one "backfire" and come loose. I also have the saito .56, and trust me--that is one smooth running engine. You will not have one single bit of trouble with it throwing the prop nut--just get it tight to begin with!

RE: Spinner question
 

I have used the Higley spinner nuts, with their lock nut on all my four strokes with no problem. You could most likely get away without double nutting this application, but anything larger may back fire and feed you the nut, prop and washers.

Here's a thread for the lock nut;

http://www2.towerhobbies.com/cgi-bin...?&I=LXL743&P=7

RE: Spinner question
 

sound like he talking about a plain spinner nut. if that's it then just put the prop on against the thrust washer then the spinner nut. use a couple 7mm washers if there is a clearance issue. leave the factory nut washer and lock washer off

RE: Spinner question
 

I really don't like the idea of not using a jamb nuts on a 4 stroke, but they aren't strictly required for operation. Just be sure to check tightness often if not using a jamb nut. Without the jamb nut, there is no friction to stop the prop from leaving the shaft during a backfire. Using an electric starter in no way guarantees the engine won't backfire. Even if needles are set right, the engine can still backfire under the right conditions. I used an electric starter on a YS-63 last summer. It fired up and then promptly kicked the spinner, both jamb nuts and prop clean off the shaft. The prop flew about 75 feet and stuck in the ground. In this case the jamb nut didn't prevent a flying prop because the kick was very violent, but in most cases, the jamb nuts will prevent flying props. I'm 99% sure my kick was due to an air bubble that was sucked into the line. I guess my whole point here is if you plan on running a 4S without the jamb nuts, give extra consideration to keeping the nut tight and always start pointing away from people (which you should always do anyway.) Cheers!