1987 Merc V150 Revves Up Wont Go

[Outrage 19]

Hi fellows,<br /><br />I was out fishing this weekend and on the way back the engine, 1987 Merc V150, revved up and we started to slow down. I put it in neutral and back in forward slow and she moved. When I started to slowly increase throttle she revved up again. I put it back in neutral then reverse, that seemed to work ok. When I went back to forward I got the same results any thing above 2000 RPM and something is slipping. What do you think spun prop hub or clutch dog? I’m hopping prop because I can’t afford lower unit work right now and fall rockfish season is just around the corner. Thanks in advance for any help or suggestions any one may have.<br /><br />Outrage 19

 

[KCLOST]

Re: 1987 Merc V150 Revves Up Wont Go

Most likely a prop hub problem...

 

[Outrage 19]

Re: 1987 Merc V150 Revves Up Wont Go

Hi KC, thanks for the reply. Does anyone have a way to do the alignment mark test with out taking the boat out on the water, or is there another test to check for hub slippage that can be done with out taking the boat out?

 

[KCLOST]

Re: 1987 Merc V150 Revves Up Wont Go

Just mark the inner hub, (the part with the washer pressing against it) and also the metal casing around it (not the outer tube, but the inner one that holds the hub)... Run the engine for a while and check to see if it slipped....<br /><br />You'll just have to wade out in shallow water to mark and view it when the engine is raised up.

 

[Outrage 19]

Re: 1987 Merc V150 Revves Up Wont Go

Does any one know a way to test with out putting the boat in the water?

 

[mellowyellow]

Re: 1987 Merc V150 Revves Up Wont Go

150hp is a lil big to run in a barrel or test tank<br />I would back it in on the trailer and test it.

 

[Outrage 19]

Re: 1987 Merc V150 Revves Up Wont Go

Didn't think of that. Thanks mellowyellow

 

[KCLOST]

Re: 1987 Merc V150 Revves Up Wont Go

Sorry Outrage, I misread your post...<br /><br />Try this, take your prop nut wrench or socket and breakover bar, (what ever you use) and turn the wrench so the prop moves in the forward direction. Use a board against the cavitation plate and blade of prop to prevent it from spinning. <br /><br />See if the hub turns/slips..

 

[Outrage 19]

Re: 1987 Merc V150 Revves Up Wont Go

I take it I want to do this with the shift leaver in neutral.

 

[KCLOST]

Re: 1987 Merc V150 Revves Up Wont Go

Yep

 

[Outrage 19]

Re: 1987 Merc V150 Revves Up Wont Go

Hay KC I took your suggestion and last night pulled the prop, marked it, put it back on, blocked it with a 2X4, pulled out the old 1 1/8 socket and breaker bar. Gave it a good pull in the direction forward gear would turn the prop and the only thing that happened was the tab washer rounded the corners on the prop washer. I’m still thinking prop hub though for two reasons. First a 150 HP engine produces a lot of torque and it only slips above 2K RPM, so I’m thinken the tab washer and prop washer might not be designed to handle torque coming from the hut instead of the shaft. Second if it were the clutch dog wouldn’t I hear a clicking or ratcheting from the dog’s teeth trying to engage?

 

[KCLOST]

Re: 1987 Merc V150 Revves Up Wont Go

Well, it was worth a try...<br /><br />The Lake test will surely let us know...

 

[Outrage 19]

Re: 1987 Merc V150 Revves Up Wont Go

OK I'll try to get it in this weekend.

 

[Outrage 19]

Re: 1987 Merc V150 Revves Up Wont Go

Hay KC the lake test is the best. It's a spun prop.

 

[KCLOST]

Re: 1987 Merc V150 Revves Up Wont Go

Good to hear!!!!

 

[Outrage 19]

Re: 1987 Merc V150 Revves Up Wont Go

Thanks for all the help KC. If you ever find yourself on the lower Potomac river look me up I’d be glad to buy you a beer or 2 or 3. Once again my faith in human nature is restored by the good people here on the Iboats forum.

 

[kipper]

Re: 1987 Merc V150 Revves Up Wont Go

to ask a dumb question what did you replace to fix the prob. prop or other stuff. sorry new to boat stuff i think i may have the same prob.

 

[Outrage 19]

Re: 1987 Merc V150 Revves Up Wont Go

Hi Kipper, first we need to know year and size of your motor so we know what to do next.