Confused on the various 300x weights listed

[CarpCommander]

Hopefully someone can clear up this confusion for me regarding the 300x motors. I’ve been doing a LOT of reading/research, and I have yet to find a clear, definitive answer.(Please-correct me if I’m wrong on any of this)

From what I’ve learned, the 300x was made from 2001-2005(?), and I’ve seen weights listed from 465lbs up to 505lbs. I’ve also seen one listed at 435lbs, and another listed for sale with the owner claiming his weighs 515lbs. All but the 515lbs were confirmed with actual pics of the factory motor tags.

But most seem to be either 465lbs or 505lbs.

I also understand they were available with either a HD single ram offshore midsection (with the pump remotely mounted inside the boat), and the standard 3 ram ‘bass’ mid section. I’ve read the offshore midsection weighs more than the 3 ram, BUT I’ve seen 3 ram motors listed at 505lbs as well. And most of the motors I’ve researched were 20”.

So….what gives??? Is it the midsection? The lower? Combo of both?

**I’d like to find a 300x with the bass mid that weighs 465lbs complete. Does such an animal exist??**

(Not particularly interested in the predecessor to the 300x-the ProMax)

(I’ve tried calling Mercury and Mercury Racing direct-haven’t found anyone at Mercury who knows, and Mercury Racing won’t speak to you unless you’re a dealer)

[CarpCommander]

And…..I’ve also got a follow up question, to my question…lol.

I’ve screenshot a pile of motor labels from motors I’ve seen online, and I’ve noticed A LOT of variation in the way they’re printed. I’ll type out a few of the labels, and would love if someone could fill me in on what the various letters mean. For example, some of the labels will read ‘PMAX 300x’, even though the ProMax wasn’t made past 2001 (I think??). Some simply say 300x, some say PM300x. Are they ProMax? 300x? ProMax 300?

I’m looking for the 300x made from 2001-2005, and all the motor labels below are from motors described simply as ‘300x’.

It’s just adding to the confusion…

Here’s some examples:

OT235227
2001
PM300X CL
Max RPM 6800
HP 300
LB 465

OT999528
2005
300X CL
Max RPM 6800
HP 300
LB 504

OT999522
2005
300X L
Max RPM 6800
HP 300
LB 504

OT652795
2003
300X OS
Max RPM 6800
HP 300
LB 504

OT652790
2003
300X OS
Max RPM 6800
HP 300
LB 504

OT998148
2005
300X L
Max RPM 6800
HP 300
LB 480

OT235227
2001
PM300X CL
Max RPM 6800
HP 300
LB 456

OT430846
2002
PMAX 300X
Max RPM 6800
HP 300
LB 500

OT818434
2004
300 XL
Max RPM 6800
HP
LB 470

OT818532
2004
300 XL
Max RPM 6800
HP 300
LB 470

OT818806
2004
300 CL
Max RPM 6800
HP 300
LB 504

OT999098
2005
300X L
Max RPM 6800
HP 300
LB 435

OT430223
2002
PMAX 300X
Max RPM 6800
HP 300
LB 456

OT430307
2002
PMAX 300X
Max RPM 6800
HP 300
LB 456lbs

OT819065
2004
300X
Max RPM 6800
HP 300
LB 435

OT818552
2004
300X
Max RPM 6800
HP 300
LB 504

OT999545
2005
300X L
Max RPM 6800
HP 300
LB 504


These are actual serial numbers and weights from motors I’ve seen online. Someone make it all make sense….pleeeeease

[EuropeanAM]

I'm not looking up every one of those numbers, but I can give you some help to understand.

Several of those are Promax models, NOT 300x models. The 300 ProMax was lighter.

The midsection weight is one difference (the HD-Offshore was actually heavier). Additionally, the GEARCASE is another contributor, as is the shaft length of the engine L vs. XL vs. CCL.

And of course, a CR engine has more/heavier gearcase internal components, so it's heavier.

And finally: Cowling configuration.

[CarpCommander]

I'm not looking up every one of those numbers, but I can give you some help to understand.

Several of those are Promax models, NOT 300x models. The 300 ProMax was lighter.

The midsection weight is one difference (the HD-Offshore was actually heavier). Additionally, the GEARCASE is another contributor, as is the shaft length of the engine L vs. XL vs. CCL.

And of course, a CR engine has more/heavier gearcase internal components, so it's heavier.

And finally: Cowling configuration.

Thanks for the insight. I wouldn’t expect anyone to look up every motor I posted, I just typed out the tag info to show the weight variance and maybe get some understanding on what they mean.

So they made the ProMax at the same time as the 300x? I was under the impression they ‘redid’ the ProMax and the improved version was the 300x. Like I said I’m still learning….

Let me ask you this-did they make a 300x (not the ProMax) with the bass midsection in 20” that weighs 465lbs? As far as u know? Like I said, I tried going to the source but they’re not very good historians on their own motors from what I gather….

[smoken86]

May I ask why you are so dead set on having one at 465 lbs? I really don't think the extra 40lbs will make much difference on the back of the boat. If it was the nose of the boat maybe.

[CarpCommander]

May I ask why you are so dead set on having one at 465 lbs? I really don't think the extra 40lbs will make much difference on the back of the boat. If it was the nose of the boat maybe.

I’m trying to keep the weight down as much as I can in the transom-I’ll have a kicker setup alongside the big motor, and that’ll add another 120lbs or so. Plus I’ll need to build a bigger fuel tank-30 gallon VS 20 gallon.

I suppose the extra 40lbs wouldn’t make or break me, but I’d like to find a lighter weight motor if they’re out there.

[Savage]

If 300HP is a absolute requirement, then I would just get the 300XS.

[JOE54]

^^^^^^+ 1 and save a ton of fuel

[Gamblerman65]

I recently went from a 300x to a 250 4 stroke mainly due to lack of parts for the 300x and that is the only reason. As stated above fuel can get expensive as I ran avgas. 300x motors are a beast. Good luck.

[EuropeanAM]

They did make quite a few of the 465 lbs models. Keep in mind some of the 300X engines shipped with no (zero) gearcase at all.

If it were me... I would not even consider one of those for long-term use. Parts are RAPIDLY becoming obsolete, and I suspect in 2 years will be extremely hard to come by in some cases.