It's dead, Mammy! It's dead!

[SkeeterStew]

Well, I fired up the old 1997 175hp ProV this weekend and flew the kids out to their favorite swimmin hole here in Oklahoma City metro. Then we made two trips around the lake before settling at our fishing spot. As we settled off WOT the motor made a rattley noise like marbles in a coffee can then died abruptly. Tried to re-start but it wouldn't even turn over.
After cooling down we did get it started for a second, but it sounded horrible like someone beating on a piece of metal with a hammer so I gave up and trolling motored part way. Called the lake patrol for a tow the rest of the way, and paddled onto the trailer. Not so fun with three kids under 10 in the boat. :(

------UPDATE------

As many of my friends here know, this was a long journey of rebuilding a very dead motor. This entire process has now been made into a BOOK that you can get at Amazon and hold in your hands, complete with full color pictures, all part numbers and tools, behind-the-scenes commentary, and a very happy ending. This was a great learning project and I hope you guys enjoy it as much as I did.

https://www.amazon.com/rebuilt-Yamah...words=outboard

Though this was a Yamaha Pro-V engine, the same process could be used for any 2 stroke outboard motor with similar results.

[Charlie206]

1. Pull the spark plugs and look for aluminum on the business end of any of them.
2. Only Yamaha will use the same controls. You can put any brand on it by changing the controls.

[SkeeterStew]

Thanks Charlie! Do controls usually come with the motors when you buy them?

[Nova Kaw 650]

Thanks Charlie! Do controls usually come with the motors when you buy them?

Controls are not part of the price of a motor, unless you're buying one installed, fully rigged, and priced accordingly.

[Late Bite]

Ouch.....

[Wild Heethen]

Well guys I did one better and pulled the head. Here's what I found.







What do I do now?



Edit: Ok, after beating two cats together and kicking a tree I calmed down enough to apply simply logic to my problem. It's just parts, right? So I can see here I need a new piston> I found one for $25.00 so that's not that bad. If I grab that, get a set of rings and wrist pin, I should be back on the water right? Sounds too simple for such a horrible problem.

If I were you I'd give Hydro-Tec a call. They might can rebuild it. They are the best with Yamaha.

[Charlie206]

At a minimum, you will need an oversized piston of sufficient size to fill the hole a machinist is going to have to bore. With rings and wrist pin bearings and take a good look at the rod bearing. Also will need a powerhead gasket set. Then you have to determine what caused it, or it will happen again right after you do all the work. That looks like detonation, carb could be lean.
what is all that crap on the wall below the piston?

[SkeeterStew]

When I inherited this motor it had the carb idle screws ran out 5 turns on the top, 1 1/2 turns on all the others. I fixed that straightaway after cleaning the carbs. I'd imagine that was what killed it. The crap on the wall there is chewed up aluminum from somewhere. Looks like bird seed. :(

It might be the chunks of piston that are missing or the rings? I don't know yet. Anyone know how I get to the other side of the motor to disconnect the piston to pull it out?

[Charlie206]

Pulling it out will not help. To repair, even an inadvisable bare minimum repair, the engine will have to be completely disassembled, and requires significant mechanical skill to reassemble.

[SkeeterStew]

Pulling it out will not help. To repair, even an inadvisable bare minimum repair, the engine will have to be completely disassembled, and requires significant mechanical skill to reassemble.

Guess I'm about to learn some skills haha. I'll do a writeup and we'll see how it goes. I've done basic mechanic work off and on for a while now because I'm not a rich fella. Gotta keep the cars on the road cheapest way possible. If I tear into it, will you guys keep watch on my thread here and let me know if I'm doing something obviously wrong?

[Charlie206]

Sure. Start by buying a repair manual or go to the library and see if they will get one for you, a good library will get it if they don't have it, and its free. Take a lot of pictures as you disassemble. A LOT. This will help route hoses and wiring and such when it's time to go back together. Make notes as you take it apart, use the notes in reverse order to put it back together. Read the repair manual powerhead removal section before getting started. That will make life much easier. Get some zip lock bags and bag all fasteners for each device as you disassemble, and write on the bag what they are for. You will thank me for that later.

[berudd]

Before I went to far into this I'd have a machinist or Yamaha mechanic, someone with the appropriate knowledge, examine it to see if it can be rebuilt. If the damage to the cylinder is so bad it can't be machined rebuilding won't be an option.

[gotboostedvr6]

Just based on how it looks your gonna need a sleeve.

That's a long and costly repair

[Skeeter9948]

You have a few options here, but if I were you I would give Chris Carson a call at (305) 852-2725 http://www.chriscarsonmarine.com/. I've worked with Chris on a problem with my lower unit on my 1997 Yamaha and he was able to provide me with a great and cost effective solution. You very well might be pleasantly surprised at the cost of rebuilding the power head. If you are determined to perform the repair yourself Chris can also be a great resource for information. Hope this helps!

[SkeeterStew]

Thanks guys. I bought a manual when I got the motor. Best thing I ever did. Today was very productive. I'll post the results and how-to instructions this evening.

[Charlie206]

It might need to be sleeved. No way to tell from that one pic.

[cwilt]

Man you jumped right in...Can't keep the children waiting! Good luck!

[ert188]

Wow, great pics! (and notes
I'm sure that will help reassembly.

[TOXIC]

Motor porn. Subscribed!!

[Late Bite]

I will be watching!!!!