Jump to content
  • GUESTS

    If you want access to members only forums on HSO, you will gain access only when you Sign-in or Sign-Up .

    This box will disappear once you are signed in as a member. ?

25 merc winding out


TNFL

Recommended Posts

When I give it full throttle it winds out and disengages similar to when you have a big clump of weeds on. I have to lower the throttle so it grabs again but it doesn't "klunk/jerk" when it grabs it just slowly goes again. I ran it with a bad prop for a while and i'm hoping that didn't damage the gears. Anyone ever have a problem like this? How did yoiu fix it? How much did it cost?

Link to comment
Share on other sites

I am not a marine mechanic, but the first thing I would do is take off the prop and check the shaft at that point for any damage or fishing line caught in it. Anything that might be replicating the prop caught in weeds situaton. best part is, this won't cost you anything for your own visual inspection. If nothing is found wrong, I'd invest in a shop manual and take the lower unit apart looking for anything bent, chewed up, or out of place.

Good luck.

Link to comment
Share on other sites

I think skindog has the right answer for you. It has happened to me twice, once on a 35 h.p. merc. once on my 9.9 merc. put it in gear turn on the prop, watch the center hub.

Link to comment
Share on other sites

The prop and shaft have nothing on them i've take it off several times to check the shaft and the prop to see if their teeth were missing.

You two seem to be on to something. full throttle/high rpm's. How do I fix it, buy a new prop?

Link to comment
Share on other sites

The splines on shaft and prop have nothing to do with a spun hub.

Propellers have a rubber "bushing" to absorbe any small impact. Easiest way to find out is to put a small paint mark on outside prop hub and inside of the hub (when you look from rear) , if hub is spun the won't match anymore.

Other causes can be motor hanging to high or tilted too much, chunks missing from prop.

If you have a stripped gear, it will be very noisy, you'll notice right away a loud grinding noise.

Link to comment
Share on other sites

I store my boat in the garage and it is winterized. How long can I run it without earmuffs to check and see if it is spinning? Should I wait until the real spring shows up? And also if thats the problem do I need new bushings or a new prop?

Link to comment
Share on other sites

Valv is dead on. That sounds like a classic explanation of spun prop sounds to me. Time for a rebuild or a new one.

I wouldn't waste time revving it out in the garage though. You might shouldn't overrev it when cold and if you run it long enough to bring it up to good operating temps without water that's no good. Besides, there is no pressure on the prop to make it slip in the garage on the trailer...

Link to comment
Share on other sites

I have always been told that you NEVER want to run the motor with no water. Have been told that is very hard on the water impeller. I don't know but that is what I have been told. Put the motor in gear and see if you can spin the prob would be one quick ckeck, depending on how loose it actually is. Have a good one and N Joy the Hunt././Jimbo

Link to comment
Share on other sites

No, no, no, don't run the motor with no water, otherwise you'll end up with more problems that you have now.

You have to test in in a body of water, you need the pressure from water when prop spins.

Link to comment
Share on other sites

You should be able to put the motor in gear and turn the prop to see if its slipping, if this fails you may be able to have a friend hold the flywheel so the motor cant turn over when your trying to force the prop. This definately sounds like you spun the hub at some time.

This is not an older motor with a shear pin is it? A broken shear pin will sometimes do the same thing. It will bind and turn the prop until the prop reaches X amount of load and then spin.

Dont run your motor out of the water. Valv stated the ideal way to test. If you live near the river maybe you can back your trailer into the water and run the motor for a minute to see if it slips.

Reving the motor out of the water is not going to help because there is no load on the prop. Dog ears(cant remember proper name) connecting the water hose to your lower unit would likely be a waste of time.

Link to comment
Share on other sites

Thanks for all the advice. Sorry I haven't responded I went up north last week. Sounds like you guys are on to it. Its seems correct that could not duplicate the situation unless i'm on a lake because it only happens at full throttle. I just want to clarify that if I buy a new prop it should solve the problem, assuming its a spun hub? Geez I wish the prop guy could have told me that before I rebuilt it blush.gif

Link to comment
Share on other sites

We are not 100% sure, it's tough to be certain without having motor.

Trying a different prop it's a start, you don't have to buy one, maybe find one you can borrow temporarily, it might narrow the search for the problem.

Link to comment
Share on other sites

If you had the prop rebuilt like it says in your last post it probley isn;t your prop hub sliping, rebuilder normally replace the rubber shock absorber in the hub, but you never know, still a good place to start. crazy.gif

Link to comment
Share on other sites

My Bass boat does the exact same thing. Ill be on plane at half throttle or so, then push it up to full throttle fast, and it'll slip. The reason for my slppage is my motor being trimmed to high. If i trim it down a little it stops, or engage the throttle slower. I would try a different angle on your motor if you think this could be the problem.

Otherwise it has to be your prop. If it is your prop you'll feel the slip, then if you back off just a bit it'll catch and your in business. or it will feel like your boat just shifted gears.

It's hard to tell if your rubber is bad in the prop just by looking at it. I would also recomend putting the boat in gear and have someone hold the wheel on the motor and see if it moves as you try to turn it. Or if you can put it in the water, mark it as noted in the other post.

I've worked on alot of boats and one thing I can tell you for shure, it's not a serious problem from the way you described it. Follow the advice you recieved from this forum and you you'll have the problem licked in no time.

Good Luck....

Link to comment
Share on other sites

I went to Formula Prop on Monday. The guy at the desk said it was probably spinning based on some metal and or rubber shavings. One of my fins is slightly nicked but the guy recommended replacing the whole unit($112 after tax) which was only $30 more than fixing everything. Seems like a good idea to have 2 props anyways, plus I can put the crappie smirk.gif one on if decide to ever float a river. I'm only slightly nervous until I get it in open water... I hope its fixed blush.gif

Link to comment
Share on other sites

Guest
This topic is now closed to further replies.


×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use and Privacy Policy. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.