Maintenance of motor that has hardly been used! Yamaha 70cv

[LauraFrance]

Hello!
Yamaha newbie here.. already a big fan!

Just bought a new boat with a 70cv Yamaha 4 stroke: 2012.

Previous 2 owners have navigated just 2h with the boat... YES!! just 2 hours in 7 years!

So, after the first hour, the boat was not rinsed or used.. the second owner purchased the boat and did an hour.. rinsed the motor and then didnt use the boat again.. he has not done much maintenance and boat has been stocked in a dry lot :

2 years ago :

- Fuel filter
- Water pump changed
- Bottom joints changed

I have turned over the boat in the bucket, starts and turns over nicely, but, i dont want to navigate until the motor has had all of the necessary servicing/pieces changed..

I am just looking for advice to what exactly I need to get done, i have planned on asking for :

- Oil and filter changed
- Cam belt : usually ever 4 years?
- Thermostat checked and replaced if needed?
- Water pump changed? It has been sitting in same position for 2 years but never used
- Spark plugs?

Anything else to check/change ?

Thanks for any advice.. much appreciated!

[TownsendsFJR1300]

The water pump probably has some "set" in it. Wouldn't hurt to change it out. R&R the LU oil while at it.

Oil and filter, cam belt should be fine.

Inspect the thermostat, especially if it sat / used in salt water, un-flushed...

Then follow break in procedures!

[pstephens46]

What type of fuel tank do you have in this boat? Internal or external/portable? I would be more concerned with good clean fuel delivery than anything else.

[FabricGATOR]

What type of fuel tank do you have in this boat? Internal or external/portable? I would be more concerned with good clean fuel delivery than anything else.

yes!

Welcome to the forum and congrats on your new old boat.

Assess the old fuel and if you have a fuel filter, replace the fuel filter/separator spin on cartridge.
Is the fuel tank full? It is best to store a vessel, especially for long term, with a full tank.

Let me ask, how familiar are you with boat ownership / custodial care? Detailed answers depend on how much you already know.

Example: Pump gas (car gas) has ethanol in it (in USA). Ethanol fuel, not so great in a moist marine environment, especially long term storage. Ethanol free gasoline is sometimes available as REC90 in most parts of the country. www.puregas.org
It is generally agreed that running ethanol free gasoline in a boat is better if it is available where you reside. If not, there are fuel additives that 'claim' to adjust the E-10 to minimize the potential draw backs of E-10.
YamaLube makes two (or more) recommended fuel additives and there are other brands too.

I am not trying to open a fuel additive debate.

What waters do you intend to navigate? (where do you live)

[99yam40]

if that boat sat for years with old fuel in it, I would be getting it all pumped out and clean the whole fuel system

[LauraFrance]

Hi all!
Thank you for the replies.

I had a yamaha 40cv on my last boat, it went through a complete overhaul in the 2 years i had it.. major lack of maintenance from the previous owners!!!! Everything got replaced or fixed..!! I have become paranoid and I like to tick all boxes with the maintenance schedule. I dont think people should mess around with the sea and maintaining a motor is the least we can do!

So, how much do i know about maintaining? Novice, but eager to learn after the nightmare experience with the other motor i had (it worked perfectly when i sold it on after the complete overhaul!)

I have the Yamaha maintenance schedule..

For the fuel : there is an internal fuel tank : I will empty completely and refill.

Boat will navigate in salt water, motor rinsed after each trip and stocked in dry lot.

I was thinking the following :

Rubber componants :
Cambelt for peace of mind
Turbine

Fuel :
Filter was changed maxi 2 years ago so i think this is ok no?
Fuel will be emptied and refilled with new fuel : at the dock we have a pump

Oil :
Checked colour and it is transparent so maybe will break in motor and get oil changed at 20h?
Filter : will change at 20h.

Thermostat :
Get it checked and change if necessary

Spark plugs etc, will get motor going and then change as per the schedule

Does this sound reasonable?

Thank you!

[pstephens46]

More than likely you have a boat mounted fuel filter. Looks like a can. Also called a water separator by some people. Also an engine mounted smaller fuel filter. At a minimum, change the boat side fuel filter after having main tank drained. Those filters are cheap. Seriously doubt you need to change the cam belt. Inspect it? Yes.

[TownsendsFJR1300]

Definitly get rid of that fuel. Ethanol fuel goes bad in as quick as a month. Two years, un-treated, bad

You can pump most of it with the fuel line / primer bulb into a portable tank.

Probably have to pull the tank to get the rest un-less you can see enough inside to wipe out with a stick and rag(and lots of flushing).


I'd at least drain the carbs(should be a drain plug in the bowl) and pump fresh fuel thru it (once the fuel tank is done) to flush any crap out..




Ethanol at it's worst:

[rodbolt17]

dog it till it is dead, whine.
do not ASSUME anything.
Oscar and felix explained that in court.
simply do the maint.
act as if it is a neglected POS and go.
face it, it was neglected.
I may even remove the cam cover and inspect for rust.
lots of shiney parts on a 4 stroke.
clear the fuel system,comepleatly.
do the FULL maint on the cooling system.
drain,pressure test,refill the gearcase.
assume nothing just because it got neglected and has only 2 hours.
if you actually care to read the Yamaha maint schedule you MAY see it has hours OR calander intravels.

[FabricGATOR]

dog it till it is dead, whine.
do not ASSUME anything.
Oscar and felix explained that in court.
simply do the maint.
act as if it is a neglected POS and go.
face it, it was neglected.

I may even remove the cam cover and inspect for rust.

lots of shiney parts on a 4 stroke.
clear the fuel system,comepleatly.

do the FULL maint on the cooling system.

drain,pressure test,refill the gearcase.

assume nothing just because it got neglected and has only 2 hours.

if you actually care to read the Yamaha maint schedule you MAY see it has hours OR calander intravels.

Seeing that you are new here, rodbolt17 is the resident Yamaha Master Technician. Sometimes short on words but usually drenched in wisdom and experience.
Actually, all these members responding to you are a great source of guidance.

Are you trailer storing in a dry lot or forklift storage in/out service?

I gather that you are a relatively experienced boat owner / custodian but not necessarily a DIY mechanic. Highest choice would be to employ a Yamaha trained technician with a good local reputation.

Myself, i would follow rodbolt's word, that is also in keeping with what the others have been advising.
Drain, clean the fuel tank. Inspect, replace as needed the fuel filters.
Remove the lower unit and replace the water pump kit.
Drain the lower unit oil, pressure test for seal integrity, repair as required, refill with quality gear oil. Lubricate the shaft splnes and bolts.
Perform any additional cooling system maintenance due at time interval
Perform any additional maintenance items due over time interval.
Consider the cam inspection for rust and address as required.
Remove, inspect, and lubricate the propeller shaft spline.
Fill cooler with beer, bait, and ice.
Refill fuel tank with non ethanol fuel and perhaps the recommended snake oil additives, if available.

Depending on where it is that you are boating and what the marina has for fuel on tap, I believe I read advertising for ValTect brand marine fuel, that claims to be alcohol free and already have the equivalent of "YamaLube Ring Free Plus" fuel additive. (or something along those lines) I'm curious about the community consensus about this bold statement.

Cheers!

[LauraFrance]

Thanks again for your input and big thanks to Redbolt! From reading all of your replies, i think I am pretty clear on what we need to do to get the boat on the water...

Just to paint the picture, i am actually in France and having spoken to 3 mechanics about this motor and i have varying opinions, hence, why i have come searching here for your wisdom!!!

Boat is in a forklift storage in/out yard.. its an awesome service!

Our experience is limited to oil changes/ filter changes/ etc but we like to know what needs doing and when.. if i ask 3 mechanics near the yard they are all saying conflicting information!!!

So far today.. its been interesting..

Drained fuel, cleaned the fuel tank and the plastic casings of the filters, replaced two of the filters : boat mounted fuel filter and second filter
**problem has come up with refuelling and fuel supply to motor.. lots of air in the system and fuel not getting to the engine.... **

Cooling system : replaced thermostat as it was in a bad shape!!!
Cam : inspected : looks brand new.. no rust/debris but mechanic will change next week
Anodes : changed the 4 externals and checked the one next to the oil filter
Oil checked : will be changed after an outing or 2 as mechanic said motor needs breaking in first ?? slight doubt about this ?

Jobs for the mechanic next week that we leave to the expert :
- Lower unit work : pump and gear oil change with lubrication shaft spine etc.
- Propeller inspection etc.
- Will ask him to check anodes in the block
- Pressure tests etc..

Anything else i have missed ?

I will be doing the 20 hours service earlier than suggested and then slip into the usual recommended maintenance schedule with all of the necessary TLC!!

Thanks again all!!

[FabricGATOR]

De rien...
bon chance!

[LauraFrance]

Ah merci beaucoup !!