I need a merc 40 flywheel lightened

[BRzuki]

Can anyone point me in the right direction? I've got a spare that I would like to have lightened.

Thanks

[fs5]

hi mate ,any engineering shop can do it.i got mine done over here in aus it cost me about $300 ,but they had to make a dummy shaft to balance it.if you got an old crank they could balance it on it would be a lot cheaper.
they spin up a bit quicker mate ,with the smaller props.i counldn't realy notice any top end gain
heres a couple pics

[BRzuki]

Thanks fs5,

How much weight did that take off? Do you feel the gain is worth the cost?

[fs5]

i can't remember exactly ,but it was a lot .i think it was around 500 grams with the ring gear removed .
i got mine done in the hope for a bit more topend ,but i couldn't realy notice it.
if you were drag racing or circut racing it would be worth while.
i've got a little 15p trophy sport with some extra cupping,it excellarates real hard with that on anywhere in the rev range..but with a 12x20p merc cleaver i couldn't realy notice much...

[zul8tr]

Most likely any gains would be in boat acceleration due to less rotating mass.

[DuckLn]

Anybody else care to weigh in on the performance gains releted to reduced weight flywheel?

[Fastjeff57]

Worked great on dirt bikes! The 'button mag' MXers would rip your fuel tank decals off in a drag race. Stalled really easy, however, especially on hard braking if you didn't pull the clutch in fast enough. (God, those were fun days!)

My buddy Bob went whacko with his lathe on a Merc 25 looper flywheel. Told him that I wouldn't want to be anywhere near that at 8 grand!

Jeff

[Mark75H]

Anybody else care to weigh in on the performance gains releted to reduced weight flywheel?

Minimal. The biggest advantage is less strain on the top bearing and seal.

The physics is even the heaviest flywheel will still easily accelerate to speed faster than your boat will.

[seapro]

Minimal. The biggest advantage is less strain on the top bearing and seal.

The physics is even the heaviest flywheel will still easily accelerate to speed faster than your boat will.

What he said I've done a lot of them mostly on motors that are going to turn up the 59 has a bad habit of breaking crank shafts if you don't

[phillnjack]

unless you are going to spend a lot of money on every other mod possible on the engine the lightened flywheel is a waste of money.

The weight is there for a reason, and in standard form gives the engine a decent tickover and more torque at lower speeds.

Unless you are racing its a no no, for average boating you wouldnt want it lightened.

the flywheel on outboards is not like a car where its realy heavy, and again only for race purpose where youl be flat out all the time.

top end will not get any gain at all.

better of spending your money on a bettter prop or other mods.


phill