120/140 outdrive and coupler questions

[gdburch]

Hello, I'm looking at a mid 70's boat with a mercruiser 120. The boat needs a little work. The owner says it won't move under its own power. When I put the outdrive in either gear and rotate the prop I get the standard ratcheting in one direction and it rotates in the other. The prop shaft is turning with the prop so I don't think its the hub. When it rotates I can feel some drag but I can move it one handed without a lot of effort. I was told that it basically started slowing down and reving up. Would I be able to rotate the outdrive if just the couple was bad and everything else was good? Any ideas? I haven't looked at th oil yet.

 

[Haut Medoc]

Re: 120/140 outdrive and coupler questions

What part of Wa? So, you are saying that with the drive installed on the boat that.....<br />You can turn the prop either way with it in gear?<br />That does not sound good....<br />There is no way you should be able to turn it by hand in gear(FWD or Rev)<br />If it overheats I would say maybe coupler.....<br />I don't think thats it though.....<br />You need to pull the drive & look at the input shaft for signs of wear...<br />More importantly, is to see if it will engage in fwd or rev off of the boat....<br />If it will, you have worn gears somewhere & need a rebuild .....<br />If the boat is cheap enough, you can get an after market drive for about &1200 new....JK

 

[gdburch]

Re: 120/140 outdrive and coupler questions

I doubt the current owner would let me pull the drive. I might be able to look at the oil. Actually, I'm not interested unless he will let me look at the oil. <br /><br />Yes the drive is installed on the boat. I shifted it in and out of gear with the shifter. That worked fine. When spining the prop the lower bearings on the prop shaft feel good. The prop shaft has a slight amount of play in and out. No worse than any other boat I've felt. I was wondering if the drag I felt was just the water pump and it had a broken gear/ shaft or if maybe the drag was also a failed coupler. When spinning everything I couldn't hear any rattling or feel any binding. Everything felt smooth.<br /><br /><br />At first I thought it might be a problem in the upper gearcase. After talking to the owner I began to wonder about the coupler but I've never dealt with a slipping coupler. He said he was running down the lake and the boat started losing speed and the engine started to rev higher. He stopped the boat to take a look and couldn't get it going again. He said he never heard any noises.<br /><br />I know the best way to determine the problem is to tear into it. I'm wondering if anyone has any more ideas about how to check it out.

 

[Bondo]

Re: 120/140 outdrive and coupler questions

Is it Possible to reach around the back of the motor,+ Feel the input shaft turn, while someone is turning the Prop,.???<br /><br />If the shaft Turns,... it's Probably the Coupler.......<br /><br />If it's Not turning,.... The Vertical shaft in those likes to Break,.. right at the Top oring groove......

 

[fireship1]

Re: 120/140 outdrive and coupler questions

Unless this boat is in really good shape. And it's going really cheap. And....Your a good wrench. I would just look for another boat. Now's the time to find one. In the winter when they are cheaper. Good luck.

 

[whywhyzed]

Re: 120/140 outdrive and coupler questions

sounds like the coupler went- just remember the coupler also turns the waterpump in the drive...many boats with a failed coupler also have an engine that was overheated- look at the hose connecting the exh. riser to the transom pipe and see if it looks cooked...paint burns at 300 degrees....

 

[Bt Doctur]

Re: 120/140 outdrive and coupler questions

Do what Bondo says. look inside at the shaft, shift into gear, have someone turn the prop. shaft moves = bad coupler<br />shaft does not move = drive shaft,gears, or other damage in the drive.

 

[gdburch]

Re: 120/140 outdrive and coupler questions

Thanks everyone! I decided to pass on this boat. There are some things I like about it but overall its not what I want. It needs new seats and with the age it may need more repairs than its worth. I'll keep an eye on it and if the price comes down I might pursue it. But right now it looks good where its at.

 

[whywhyzed]

Re: 120/140 outdrive and coupler questions

good call...<br />It's worth nothing more than the trailer... hopefully more potential purchasers will do the research you did...<br />I tried to sell my 75 boat with a 3.0 and it runs...new coupler even.. I put in the paper and got no calls at $200.. So I parted it- got $1000 so far in parts sales and I still have the outdrive... so there...blaaaa (sticking tongue out at the world...)<br />

 

[gatorred]

Re: 120/140 outdrive and coupler questions

yes hystat you buy it they want big $ when you sell it they want you to give it to them or you pay them ok what part do you want i got more then that in prop,if it's a SS prop, that why i left i paying 1500 in tax's for a 10,000.00 $ boat and they want to know the price? well i give away a 2500 trailer and leave, ok