Four Stroke Mercury's how long before rebuilding?

**Brad Zastrow** · 01-23-2022, 08:00 PM

The one with the wing plate and side ram steering.

**engineermike** · 01-23-2022, 09:05 PM

In case anyone was wondering, a brand new set of 32 valvesprings for a new 4.6 v8 is $105, MSRP. A head gasket is $60. Rings for one piston is $66, which is a little steep but I pulled up some OEM automotive ring sets and found a range of $30-$84 so it's right there with them.

Something else worth noting is that the Mercury marketing materials actually say 40% more torque at 2000 rpm, not across the board. I attached the snip. And yes, it is quite possible that one engine has 40% more torque than another at 2000 rpm, but the same power at 6000 rpm. So, there is no evidence Mercury is lying about this.

**Z06man** · 01-23-2022, 09:15 PM

The AMS is the heavy mid he is getting Wingplate CMS they list low 500 weight.

**JPEROG** · 01-23-2022, 09:49 PM

Originally Posted by RiverRat71

Reading another thread about V8 motors way too heavy for any boat I will own. I appreciate their application & don't doubt their performance but what about yesteryears smaller hi-perf boats? Merc where are you? Anyone? RR

I had a 300xs on my Allison, a 300X on my STV, and have new motors on my LCBs (they are very close in weight). If you are running anything with less mass then an STV or Allison XB2003 then I agree the new V-8 motors are not the answer but its almost impossible to run anything smaller then that on todays water ways where wake boats, cruisers, and 25' tri-toons are the norm. For guys that still want to run the sub 20' hulls, all we can do is hope the V-6 progress continues to make its way to the market.

Joe

**Chaz** · 01-23-2022, 11:39 PM

Originally Posted by John S

No. And in all your condescending blabbering, you haven't answered the OP's.

Asking how long between rebuilds , is like asking me what color shirt your wearing.

Does the owner take advantage of the phenomenal torque at 2000 rpm to impress his friends or is it one (or more) of those "demo" motors that have been whooped on for 200 hrs .. never been registered and brought back for service .. OooHHH Oohhhooooo
Dealers tend to register motors the day they leave their possession .. boat builder types .. not so much .

Did you find that condescending as well .. ???

Sorry bout feelings , but its true .. just like everything else I have said ...

If you really need a baseline to go by ..

I know guys who hang a motor together, put two dyno pulls on it. Pull it apart, messuage the high spots, put it back together , three qualifying shots , four round race .. home and the process starts again.

Will it troll its life in the Gulf stream ???

Weekend warrior .. ???

Drive it like ya stole it .. demo boat .. ???

1000 hours was mentioned .. gotta be as crisp as a wet noodle

But if it still runs .. then OK

Goes for about any motor .. average 60 mph for 1000 hrs = 60,000 miles.
Your maffus skiiLz and results may vary ..

Well Mike .. four stroke , cam and compression for 87 octane , 35% bigger .. and all they can claim is 40% more torque @ 2000 rpm than the 7 cylinder ...

Post a link to the part numbers , prices , I can check Mercnet for availability ...

Joe , like the guy in the hot sauce commercial says .. I (they) put that **** on everything .. or does it have to be a Skater or a DW for it to count ..

Some people still consider a 300x as being king .. go to the boat drags, look around, 2.5's are still King. Everybody is entitled to their opinion. Unless you flopped to the other side, where freedom of speech no longer counts ..

Speakin of LOTO .. I noticed that for the last couple years .. the numbers called out from the bluff don't seem to match the sales pitch .. just an observation ..

**engineermike** · 01-24-2022, 09:20 AM

Originally Posted by Chaz

Well Mike .. four stroke , cam and compression for 87 octane , 35% bigger .. and all they can claim is 40% more torque @ 2000 rpm than the 7 cylinder ...

300R vs 300XS, by the numbers:

1% more engine weight
44% larger swept volume per revolution
40% more torque at 2000 rpm
5% more peak torque
7% more peak power
93% higher BMEP at 2000 rpm
46% higher BMEP at peak torque
49% higher BMEP at peak power
50% longer factory warranty
4 numbers lower minimum octane required (17% lower fuel cost)
and so on...

Originally Posted by Chaz

Post a link to the part numbers , prices , I can check Mercnet for availability ...

Mercury has made finding part numbers extraordinarily easy. I'm certain you can figure out it.

**Chaz** · 01-24-2022, 09:51 AM

You forgot the most important spec. $37,000.00+ msrp + scalper fee's ...

$3.28 cent valve spring .. no wonder you didn't provide a link ..

Chaz = predicting, toaster mike will start an argument and with-in a half a dozen post's .. whine to Greg .. he's picking on me ..

**engineermike** · 01-24-2022, 10:18 AM

Originally Posted by Chaz

You forgot the most important spec. $37,000.00+ msrp + scalper fee's ...

MSRP is up 13%, no doubt. Like it or not, it's in line with inflation. The end result is a higher quality product for an equivalent inflation-adjusted price. As far as scalper's fee's, we live in a free market economy. No one is forcing anyone to pay those prices. If you want pricing controls, move somewhere Socialist.

Originally Posted by Chaz

$3.28 cent valve spring .. no wonder you didn't provide a link ..

Are you saying that price is incorrect? Looks like the going rate is actually $2.34, or about $75/set.

Originally Posted by Chaz

Chaz = predicting, toaster mike will start an argument and with-in a half a dozen post's .. whine to Greg .. he's picking on me ..

Can we keep the thread technical? Just PM me the personal attacks so all these other folks who want to talk engines don't have to read the "condescending blabbering". Seriously.

**Double Rigged** · 01-24-2022, 10:41 AM

Originally Posted by Brad Zastrow

The one with the wing plate and side ram steering.

Yes those are much lighter.

**John S** · 01-24-2022, 02:24 PM

Originally Posted by river rocket

They nailed the 300R, it is an absolute power house. The only thing I miss about a 300x and my 2.5's is the sound, but the 300R sure sounds good on a cold start. Maybe not the 300X crackle, but still good. What is even better about the sound is it just makes noise when the key is turned and then it is quiet after a few minutes. Which is so awesome to be able to idle around and not have to talk over my motor. Man I'm getting old..... I went back to a premix 2.4 BP this last season while I waited for my boat to be built and my new motor to show up and man I couldn't wait to get rid of that old stuff. I just want to turn the key and go fast.

The 300R was such a fun motor to own. Reliable, low maintenance, turn key power. I absolutely punished mine. I had just short of 300 hours on it and virtually every morning I was out doing hard acceleration runs on it right up to the limiter. Pass after pass after pass. We did tons of testing with it for Fastbass Marine and Allison. Something that I was super impressed with was how consistent it was. When prop testing with a data logger it would log pass after pass with no changes. Unlike the 300XS, I could only make 1-2 passes before it would fall off and start slowing down. I could test 5 to 6 props making 3-4 passes each and make real comparisons without having to worry about the motor being the change.

I never had an issue with the motor in the couple of years I had it. I can't wait to hang my 450. Spring can't come soon enough.

Have you guys ran the 300R on an xb 2003, or just the xb21? Sounds like your having a helluva good time testing. Hard to catch fish at triple digits.

**river rocket** · 01-24-2022, 03:54 PM

John, the 300R was on a 2003 in Texas for a bit and some others exist. Fastbass has one that is suppose to get one here sometime this spring or summer when the motor comes in. Like the XB21 and 450R, you have to take the time to see what the boat wants and how it reacts. Several 2003's have run with that weight or similar weight so its more of a gear case learning curve I would imagine.

**Chaz** · 01-24-2022, 05:39 PM

Originally Posted by engineermike

MSRP is up 13%, no doubt. Like it or not, it's in line with inflation. The end result is a higher quality product for an equivalent inflation-adjusted price. As far as scalper's fee's, we live in a free market economy. No one is forcing anyone to pay those prices. If you want pricing controls, move somewhere Socialist.

All I did was mention the msrp price. And as per JP's post .. people that have them are asking scalpers prices for them. No need going into how it got to those prices or of business practices of those who hold a hot commodity.
I mentioned .. bring the vig when you go to get it .. How you made the jump to move to a blue state is beyond me ..

However, there is an economics lesson i can learn from you. Since I doubt you own your own company , posting on company time is stealing .. only scumbags do that kind of thing ..

Are you saying that price is incorrect? Looks like the going rate is actually $2.34, or about $75/set.

Try to stick with me, 4 valve head , 8 cyl motor = 32 springs. You said $105 for a set 105 / 32 = $ 3.28125 each Pretty simple really

More importantly is that Mercury finally let their parts dept know that they were building new model engines. Well, according to you anyway. I'd looked maybe a year ago .. no parts breakdown then .. and where I look for jobber prices, no breakdown now either ..

I asked for a simple link .. bless your heart .. your still lookin for a bird on the ground ...

Can we keep the thread technical? Just PM me the personal attacks so all these other folks who want to talk engines don't have to read the "condescending blabbering". Seriously.

Do you know who Eddie Haskil was, he was a little weasel that tried to look good in front of Mrs. Cleaver . Yet all the while was a low life conniving dog in reality.

You poor thing .. what personal attacks .. Pppfffttttt

A socialist .. LMAO

I can figure it out , it's not too hard ..
I gave you a specific parts list, you failed miserably

condescending blabbering .. I thought engineers were sposta have an imagination .. come up with your own diatribe .. copy cat

PM you, is gonna save the membership .. (become a supporting member then .. cheap azz)
If you need a pen pal, try the prison system .

Don't know about where you come from, but from here, that stupid stuff don't sound technical , (btw this is the general section) it's stuff that only a little weasel would say. ..

**Stoker boy** · 01-24-2022, 06:58 PM

It seems today’s trend is everybody likes big tuna boats. To each his own. I still prefer my little light Mirage with a 2.5 drag. They have to be the easiest motor in the world to rebuild. A little bit pricey but so is everything else.

**JPEROG** · 01-24-2022, 10:49 PM

"Speakin of LOTO .. I noticed that for the last couple years .. the numbers called out from the bluff don't seem to match the sales pitch .. just an observation .."

Charlie,

I think you better attend the LOTO in person so you don't miss it. There is hundreds of miles of running side by side that takes place all week. Come show everyone how fast they aren't....you can stay at my place or park your motorhome at our barn, either way bring your weapon of choice to the shootout and play for the week. Last year there were several people in our group that ran 1500 miles or more in a 10 day period.

https://lakeoftheozarksshootout.com/2021-results/

Rusty Williams ran 126 in a 36 Doug Wright with porkchops, Taylor Scism ran 122 with porkchops in a 34 MTI, Tony Chiarimonte went 118 with porkchops on a 37 DCB--These passes are now 3/4 of a mile. I ran my boat this morning to 133 with a pair of 5 blade cnc 37s (really impressive to me on 87 octane fuel that I can get anywhere and with a full warranty as well--watched testing of a new playcraft 31' tritoon with twin porkchops run 84 mph this afternoon-- (NEVER before was this possible until the new motors were released).

Joe

**OnPad** · 01-24-2022, 11:01 PM

I know I should mind my own buisness, but i can't help myself. Chaz makes a valid point in longevity being related to the way these things are operated. Our local marine patrol uses twin honda 225's, they get thousands of hours idling around. My buddy put one on a bass boat, and it smokes more than my 2 strokes, after only 150hrs. Another neighbor mounted a 150 four stroke Yamaha on his bass boat. It got a replacement powerhead at 50hrs, timing gears failed. I don't wish these scenarios on anyone. But my poor ass is going to hang on to my old junk 2 strokes, for my little boats.
How about that Dodge Neon that's fast!