3Squids '79 Center Console thread

[Destroyer]

When I bought a lower for my 200hp Mercury 2.5L to convert it from a 20" to a 25" I think the total cost for shipping was less than $50... and that included the lower and the mid extension unit. Shipping shouldn't be that much.

[3 Squids]

Originally Posted by Destroyer

When I bought a lower for my 200hp Mercury 2.5L to convert it from a 20" to a 25" I think the total cost for shipping was less than $50... and that included the lower and the mid extension unit. Shipping shouldn't be that much.

Nice. Did you go with SEI? If so how has it performed?

[3 Squids]

So I got the boat back today with a running motor!! Motor sounds great. I was talking to the motor guy and he believed the lower unit will be fine. He said it appears someone used the wrong type of nut on the prop shaft and the threads have minor damage to them. He told me to bolt the prop on if it torqued down properly and didn't strip any thread I'd most likely be fine. He also suggested using a cotter nut and drilling a small hole through the shaft for a cotter pin. But mechanically all seems well the the lower unit.

So for now the motor will probably rest for the winter until I figure out what I'm going to do about the transom. Even the motor guy agreed it was done completely shoddy. Everyone I talked to said the guy was slow but incredible at glass work. I'm not sure what happened but now I'm now sure what I'm going to do with it. I feel no matter what the structural integrity has been compromised due to him cutting the whole back of the boat out and apparently I'm not the only one as everyone that's seen it can't believe it was done that way.

Part of me just wants to rip it all back out and start over with an empty shell but
1- it still bothers me the back had been cut out and it will always be a weak link
2- getting out what he did is probably going to be a nightmare.

Any inspiration would be greatly appreciated. This boat definitely has me down in the dumps about it.

[Destroyer]

Originally Posted by 3 Squids

So I got the boat back today with a running motor!! Motor sounds great. I was talking to the motor guy and he believed the lower unit will be fine. He said it appears someone used the wrong type of nut on the prop shaft and the threads have minor damage to them. He told me to bolt the prop on if it torqued down properly and didn't strip any thread I'd most likely be fine. He also suggested using a cotter nut and drilling a small hole through the shaft for a cotter pin. But mechanically all seems well the the lower unit.

Before you go and start drilling holes do like a professional machinist would do. Get yourself a couple of thread files. They come two different ways.. one is just a single "V" shape that you place in the grove of the good threads and work backwards towards the damaged threads (useful for a quick touch-up where one thread goes over the next). The other is a long square bar about 9" in length. Each end has 4 different thread sizes ground into it, one ground into each side, for a total of 8 different thread sizes per bar. Buy the bar that has the threads you need on it, lay the correct side of the bar in the good groves like the previous file and work your way from good threads to the bad threads, filing away the damaged parts of the thread as you go. The advantage of this type of file is that since you always have a few teeth ( VVVVVVV) in the good threads your chances of success with restoring your shaft are greatly increased. Most places that sell industrial and machine shop tools will carry them. Harbor Freight even has some, that, although not the best quality, should do the trick as long as the threads marked on the bar match the ones on your shaft. Be aware that they come in both SAE and Metric, so choose carefully. You'll need to know the diameter and how many threads per inch (TPI) your shaft has.

[3 Squids]

Originally Posted by Destroyer

Before you go and start drilling holes do like a professional machinist would do. Get yourself a couple of thread files. They come two different ways.. one is just a single "V" shape that you place in the grove of the good threads and work backwards towards the damaged threads (useful for a quick touch-up where one thread goes over the next). The other is a long square bar about 9" in length. Each end has 4 different thread sizes ground into it, one ground into each side, for a total of 8 different thread sizes per bar. Buy the bar that has the threads you need on it, lay the correct side of the bar in the good groves like the previous file and work your way from good threads to the bad threads, filing away the damaged parts of the thread as you go. The advantage of this type of file is that since you always have a few teeth ( VVVVVVV) in the good threads your chances of success with restoring your shaft are greatly increased. Most places that sell industrial and machine shop tools will carry them. Harbor Freight even has some, that, although not the best quality, should do the trick as long as the threads marked on the bar match the ones on your shaft. Be aware that they come in both SAE and Metric, so choose carefully. You'll need to know the diameter and how many threads per inch (TPI) your shaft has.

Definitely going to look into that first. Thanks a bunch. I never knew such a tool existed.

[Destroyer]

Originally Posted by 3 Squids

Definitely going to look into that first. Thanks a bunch. I never knew such a tool existed.

One picture is worth a thousand words, etc. I'm not endorsing this particular brand or dealer, but this is what a thread file looks like, as shown in the picture. They (the files) come in several different types, to cover all the different thread sizes that are on the market.

http://www.ebay.com/itm/8-IN-1-THREA...656516&vxp=mtr

[Destroyer]

Originally Posted by 3 Squids

Nice. Did you go with SEI? If so how has it performed?

No, I bought the lower from a rebuild shop in Fla that is on eBay a lot. It was a few years ago so I'm sorry but I don't have the company's name .