how long do blackmax engines live?

[jigmister]

1986 175hp compression is perfect. just rebuilt carbs and new glass reeds.
Thing runs perfectly.

how long can this old beast last?

Do the piston rings and cylinders wear out or do they just keep going until somthing causes them to blow or burn up like running with trashed impeller or lean condition?

 

[oldman570]

Re: how long do blackmax engines live?

As long as the motor is maintained and given TLC they can last for a very long time. I have motors from the 1960's that still get the job done just fine. Yes the rings will need to be replacedand the cylenders honed when the compression gets to low. Others here on the fourm have motors older than that. It depends on the actions of the owner.
Oldman570

 

[Chris1956]

Re: how long do blackmax engines live?

Check the compression and keep it as a reference. Wear will be minimal and the motor can outlast you, as long as you keep up on maintenance (water pump, gear oil, carb cleaning) and don't break any NLA parts....

 

[CharlieB]

Re: how long do blackmax engines live?

With PROPER maintenance the motor can last more than your lifetime, without, you could kill it next weekend.

You must be absolutely religious about quality oil, especially fogging the motor for any off-season lay-ups.

Clean carbs, fuel filter/separator, R&R fuel pump, hoses, water pump, and poppet valve on a regular schedule, at least every third year, all contribute to a lasting motor.

 

[jigmister]

Re: how long do blackmax engines live?

What oil should I run? I make sure its tcw3.

Also when I am at or near WOT and come of the throtle fast I get a chattering sound.

I have been told that this is reed vavles clacking. Now I have glass reed before they were stock. The sound was present then as well.
Is this detonation or reeds? anything I can do to prevent this other than coming off plane slower?

 

[Faztbullet]

Re: how long do blackmax engines live?

Also when I am at or near WOT and come of the throtle fast I get a chattering sound.

Thats the clutch dog in lower unit racheting... All the V-6 2.0 liters engine will last a long time but the cylinders do wear at a taper due to the side thrust of pistons, I have see engines with decent compression have cylinders worn enough you could insert a .
010 piston!!!!

 

[jigmister]

Re: how long do blackmax engines live?

when these guys wear the cylinders what do we do being the its chrome bore?

Is the ratcheting clutch dog I hear in the lower unit a normal thing?

 

[Faztbullet]

Re: how long do blackmax engines live?

when these guys wear the cylinders what do we do being the its chrome bore?

The chrome bore blocks do wear out as the chrome will get thinner and distort/shift and still have good chrome finish. When this happens to a chrome bore it is now cheaper to toss it and replace it with a 2.5 block as you can only Nikasil or sleeve these blocks,US chrome does not rechrome them anymore. Its cheaper to find a block than sleeving or Nikasil plating.

Is the ratcheting clutch dog I hear in the lower unit a normal thing?

On any V-6 before 1995 ....yes

 

[CoffeeHound]

Re: how long do blackmax engines live?

What oil should I run? I make sure its tcw3.

Also when I am at or near WOT and come of the throtle fast I get a chattering sound.

I have been told that this is reed vavles clacking. Now I have glass reed before they were stock. The sound was present then as well.
Is this detonation or reeds? anything I can do to prevent this other than coming off plane slower?

As with all 2-cycle motors, no matter if they are brand new or 70 years old ,, it is best to come off WOT slowly so you don't lean out the fuel mixture to the crankcase. It is also easier on the LU and your passangers !!