Refurbishing Yamaha Outboards

[Horg]

I have 20+ year old twin Yamaha 2 strokes. Can they be overhauled to extend their life? If so, is it worth it?

Thanks
Horg

 

[Fishtales]

You can have them disassembled, inspected and proactive work done. Comes down to cost and experience of the mechanic. Even then, you have not eliminated risk, only mitigated it at best.
I'd be inclined to do proper maintenance and ask the mechanic what he recommends.

 

[Horg]

Thanks for your prompt response. I'll check it out with a Yamaha certified mechanic.

 

[seasick]

If you know how the motors were treated for the 20 years, that will help make a decision. If treated badly, abused, not maintained or not run very much, the damage is already done.
Why do you think they need refurbishing? Do they run? That's the first step I would take and if you don't know the history and the motors run, then do what would be routine maintenance. I wouldn't put a lot of money in 'overhauling'. I have a 22 year old 2 stroke Yami and it runs very well. Some day it will probably die

 

[Horg]

If you know how the motors were treated for the 20 years, that will help make a decision. If treated badly, abused, not maintained or not run very much, the damage is already done.
Why do you think they need refurbishing? Do they run? That's the first step I would take and if you don't know the history and the motors run, then do what would be routine maintenance. I wouldn't put a lot of money in 'overhauling'. I have a 22 year old 2 stroke Yami and it runs very well. Some day it will probably die

Seasick:

Thanks for replying. I bought the boat with motors 5 years ago. According to the broker the prior owner was a serious fisherman who put a good many hours on the engines but also maintained them. I have maintained them during my ownership. The engines run fine with the exception of one which will occasionally quit when trolling at low speed. I just don't want them to croak in
mid-season leaving me with a $30,000 problem if it can be avoided for a reasonable expense.

 

[SkunkBoat]

How much do you use the boat?
Where do you use it? Lake, Bay, Coastal/inlet, Far offshore?
That is a mitigating factor. If a motor dies in the bay, you putter home on the other one and get it fixed....
How long are you going to try to keep them running?


Salt water boat? It could need engine anodes... that are stuck.
Eventually, over time, it will need;
trim/tilt rams that are pitted, trim motors that are rusted
Lower unit seals
swivel shaft binding on dry grease
LP fuel pumps
HP fuel pump
*VST filter...
*cleaned or new injectors..unless its carbuerated (uuhg!)
* do the * things now
Stator assy
regulator
Coils

Then there are the catastrophic things that could happen at any moment that make doing those things a gamble.



Labor is the killer. If you can do things yourself as they happen, it could be more feasible than buying new motors...unless you are running offshore

 

[greauxpete]

---

What is the compression in the motors? Compression needs to be checked with: warmed up motor, all spark plugs removed, throttle open to WOT, and a fully charged battery. If compression is 115-120 psi the motor has very little wear. If less than 90 psi there is damage (such as scoring in the cylinders) or it is significantly worn.

This is the best measure of wear in a motor. Your stalling issue could be a carb that needs cleaning, dirty injectors, or spark plugs that are fouled. (You don't mention if it's a carbed, fuel injected, or DFI engine (hpdi).

Frankly, I would check compression, document the pressures in my log, address the stalling issue and keep running it.

 

[seasick]

Seasick:

Thanks for replying. I bought the boat with motors 5 years ago. According to the broker the prior owner was a serious fisherman who put a good many hours on the engines but also maintained them. I have maintained them during my ownership. The engines run fine with the exception of one which will occasionally quit when trolling at low speed. I just don't want them to croak in
mid-season leaving me with a $30,000 problem if it can be avoided for a reasonable expense.

What are the motor models?
When the motor stalls while trolling, what revs are you running. Also, does the motor just die or does it shudder first. The first case is often due to low fuel delivery rate/pressure and can be a filter, low pressure fuel pump, or a out of spec idle rev ( not likely when trolling).
Diagnostics steps depend on the model of motor. A fuel pressure test would be on my list of diagnostics.
If you tell a shop to do whatever is needed, you could be in for an unpleasant surprise with the costs and more so, may still have the same issue. You need to find the cause first and have it fixed.

 

[Fishtales]

For the cost involved, I'd roll the dice and run them until you have to replace. Yes, you may loose some time on the water if/when they die and you will likely have to wait to get new motors. That all being said, it's a big proactive nut and I'd take my chances. You may see motor leadtimes continue to drop so impact might not be as bad as you think.

 

[seasick]

For the cost involved, I'd roll the dice and run them until you have to replace. Yes, you may loose some time on the water if/when they die and you will likely have to wait to get new motors. That all being said, it's a big proactive nut and I'd take my chances. You may see motor leadtimes continue to drop so impact might not be as bad as you think.

I also agree. You may want to fix things as they pop up but it's an older motor and some components just wear out and are either not easily replicable or worth the cost to replace

 

[Mustang65fbk]

I think the two biggest considerations will be the cost of repairing vs buying new, as well as the availability of parts for outboards that have since been discontinued for quite sometime. Does the one motor that quits while trolling ever quit when going at faster speeds or is that literally the only issue that happens with it? If that's the only issue that it currently has, you might want to look at other causes first, like fuel starvation and so forth. I know my uncle's old boat had twin 2 strokes on it and one motor would quit randomly as well, especially when trolling, and we finally figured out that it was the fuel line/bulb had pinholes in it that was allowing air inside. After a new fuel line, we didn't have the issue again.

 

[Horg]

Thank you all for your thoughtful comments. I will review them and determine my next steps.
Horg

 

[Horg]

I appreciate all of you who replied on my "Aging Yamaha 2-strokes" question. There certainly a lot of knowledgeable people with sensible advice on this site.
Thanks again.
Horg

 

[luckydude]

I appreciate all of you who replied on my "Aging Yamaha 2-strokes" question. There certainly a lot of knowledgeable people with sensible advice on this site.
Thanks again.
Horg

Horg,

On my first boat I had a Yamaha 150hp 2 stroke with carbs. I hated that engine even though I was told it was a work horse. It turned out my problem was my fuel lines, they were rotting from the inside out. If that were my boat, I'd be pulling the line off the water separator and trying to stick my pinky in the hose and moving it around. Black flecks? Yeah, replace all the fuel lines.

The guy I sold the boat to eventually repowered with a 4 stroke honda.

Good luck.