prop and spark plug question

[cbsykes]

Performed maintenance to my 25hp 2 stroke Yamy over the weekend and have a couple questions for the gurus. Replaced the spark plugs but did not have a torque wrench. So, I tightened them 1/4 turn past finger tight. Is this adequate? The engine started so I am assuming it is. Also, I inspected the prop shaft and all was ok...however, when putting the prop back on I wasn't sure which way the thrust washer went back on. I put it on so that it fit firmly against the seal. How do you know which way is correct? In addition, is it normal for the prop not to easily slide back on? I had to knock it back into place with a block of wood and a hammer. I also screwed the prop nut back on a 1/4-1/2 turn past finger tight...is this adequate? Sorry for the novice questions but I am new to this. Thanks in advance!

 

[deejaycee_2000]

Re: prop and spark plug question

you should never torque your spark plugs, breaking one off is not fun, 1/4 fast finger tight might not be enough though, you should give it a good tight turn with one hand ... should do the trick ...... your prop should slide back on easily, so better check that, the prop nut should also just be turned with a good one hand tight twist ........

 

[WillyBWright]

Re: prop and spark plug question

Actually you can torque the sparkplug, but I'll bet there isn't a mechanic here that does. The spec won't break the sparkplug or strip the threads. It'll be appropriate for the application. But admittedly we all do it by feel. Sparkplugs have a crush washer. 1/4 past snug might be enough for a used sparkplug, but it would take more for a new one.

The flat of the thrust washer would face the prop. It will also have a tapered bore that would mate to the taper on the shaft. Nut torq is good and tight. I'm sure there is a spec for that too, but again we all do it by feel. With that cotter pin involved, getting the hole and slots aligned at exactly the specified torque would like winning the lottery.

The prop should slide on and off without effort. If you had it rebuilt lately, grindings are probably sticking to residual grease in the prop splines.

 

[cbsykes]

Re: prop and spark plug question

Not sure why the prop didn't slide on easily?? I have not done a rebuild or anything like that. It slides on about 2/3 of the way and then it sounds like it hits metal. I placed a piece of 2x4 on the prop and knocked it the rest of the way on. Hope I didn't damage anything doing that. Do you know anything I can do to fix this or will it be ok as it is? BTW, the prop spins fine when engine is running. Thanks in advance.

 

[cbsykes]

Re: prop and spark plug question

After more and more inspecting...I have noticed that there is a part with grooves that seems attached to the propeller (maybe welded??) that is out of alignment with the grooves inside the prop. I believe that is stopping my prop from sliding on easily. I have ordered another prop and spacer(not sure if I needed spacer or not?) in hopes of fixing this. What exactly is the name of the part that is out of alignment and what could have caused it to become un-aligned? Thanks in advance again!