300r vs 300xs on same boat

**Capt.Insane-o** · 02-23-2020, 08:29 PM

The x wasn't that great of a motor. A lot was left on the table with that one.

**Dave Strong** · 02-23-2020, 08:43 PM

Originally Posted by Capt.Insane-o

The x wasn't that great of a motor. A lot was left on the table with that one.

But it had great potential.

Dave

**Chaz** · 02-24-2020, 12:16 AM

Originally Posted by Capt.Insane-o

The x wasn't that great of a motor. A lot was left on the table with that one.

So I took a set of 14* Dart/Olds/GM part numbered heads to a friend of mines Cylinder head / manifold porting shop in Ft.Lauderdale to put fresh eyes them. He put a light spring on a pair of stems and took 5 or 6 readings on each side up to an inch of lift.
When he was done, he said grab one of those hemi heads (a pallet load of BAE heads)
and put in on this table .. he said, tell me what I should do to these to make them better. I said dude, your my teacher .. I don't really see anything that doesn't "look just right" .. He said exactly, I can't do anything to yours to make them any better either .. which made me feel a little better about the time I spend pouring rubber port molds , moving a wall or roofline up or over, bench testing it , pouring more rubber, changing the throat percentages ... etc etc etc ... and by then, I was finding and losing crumbs, no more big gains ..

My point .. It's hard for even the best to find improvement in highly developed pieces. But if you start out with a POS that was machined on 50 year old tooling by people who could give a **** about anything other than getting a paycheck. You could just about trip and fall into big gains in power and reliability ...

**Double Rigged** · 02-24-2020, 01:55 PM

Originally Posted by Capt.Insane-o

The x wasn't that great of a motor. A lot was left on the table with that one.

I agree but EPA pretty much killed any further hp gains from Mercury. Motor was going to be their 400hp two stroke.

**johnmiffco** · 02-27-2020, 11:43 AM

speed on water just released an article
new 2019 28 skater flat deck rigged with the new 300r 4 strokes
grant racing (which is 1 of the best out there setting up offshore race hulls) and with the mercury racing team
took boat to lake x couple weeks ago,,,,
and did full testing with many props and gear case changes,,,,1.6 and 1.7 ratios
the best it did was 114mph with 1 person and lighter on fuel
111 with 3 people and 1.6 gear,,,,,108 3 people and 1.7
in article shows all specs of props and gearing to mph and time to get there
so,,,,,now that's a new 28,,,,not old 90s model,,,,,new motors and the best people and props and cases
an old 90s 28 skater ((( little moisture in the core,,,mabe repaired a few times,,,painted a time or 2,,,ect,,,so prob a bit heavier
with 3.2 300xs common dialed in hull is 112-114,,,,some faster with bolt on parts and tune
with 3.0 300x common is 114-116,,,,and of course some faster 118-120
with the 2.5 280 common is 113-115,,,,,lighter motors and more rpm,,,
so now in 25 yrs of these 280/300 merc motors on same hull through the yrs
don't see much true difference of the new 4.6 4 stroke for the money
vrsing the (old junk) 2 strokes of yester yr,,,,,
280 being the simplest and lightest motor 380lbs to the 300 4 stroke ,,merc list at 515 but randy weighed with cowl @ 550lbs
now the 4 stroke is all we have new so gotta deal with it when want new
but ,,,,,,,,the old junk 2 stroke is simpler and can make big power very easily over stock trim for very little extra
for now ill stick with my 98 28 im restoring with 300x design motors,,,but are being bumped up with standalone, porting and comp,,,3.2 crank and 40 bore to 3.3 to pull larger prop and have less money spent on buying and building both motors than cost of 1 new 4 stroke
just my 2 cents

**mikesufka** · 02-27-2020, 12:06 PM

^^^

Very interesting !!! Thank you.

MDS

**Z06man** · 02-27-2020, 12:19 PM

Are the new Skaters slower or whats up . 28 Nordic went 113 with 300R . Every DW 28 Fat Cat has gone over 120 with 300s Heck with 4 of us Skater Dave , Brad Z. Myself and 1 more passenger we went 114 and was still climbing with Dave driving the boat the very 1st time. And we only had the Hill 5 Blades if only Mercury would loan me some of their 5 blades .

**johnmiffco** · 02-27-2020, 12:32 PM

don't have that answer on slower being new,,,,is flat deck with full wrap windshield vrsing older out of mold hulls
i just relayed the articles results of a lake x test session
of the new 28 with 300r and the common speeds of 25 yrs of same hull and 280 and 300x,xs
this thread is comparison of the 300r and 300xs on same hull and the 28 been around since the 90s through mercs yrs of motor designs

**Z06man** · 02-27-2020, 01:17 PM

I did not know it had a windshield just looked at the article That does slow them down always wanted to try the DW 28 without 1 but it is no fun installing and once it is on there you don't want to do it again .

**Davidlake** · 02-27-2020, 01:30 PM

The 28 Skater flat deck that was tested a Lake X was stated to weigh 5000#. That is approximately 1050# heavier than my 2013 28 Skater std. deck w/ Aero Marine windshield. I think the weight is the factor.

**Double Rigged** · 02-27-2020, 02:22 PM

I agree that at 5000lbs it is very heavy. Also need to note it is not a stock 28 configuration but a widened tunnel. The additional weight in a boat like that equates to about 2mph per 200lbs. Not to mention the downforce of the windshield. Lastly this is a real verified test done at Lake X with real information. Not a bunch of numbers being thrown around about what someone else's boat runs LOL. The DW 28 is not a fair comparison to the Skater as it is lighter and the sponsons are much more shallow on the angle of attach. I do not think the DW would run with the 28' in rough water. JMO

**johnmiffco** · 02-27-2020, 03:03 PM

agree ^^^^^^

**Trimmed Out15** · 02-27-2020, 05:11 PM

Total different boat then the classic 28 Skater. Not a fair test. Same boat different motors is the only fair test

**Z06man** · 02-27-2020, 06:55 PM

Randy has had 300xs and 300R on the same boat 21 and 25 . Steve's Bullet changed out on same boat Allison Bass boat posted his results with fuel load acceleration etc same boat .24 Skater changed over they all have posted there results . All had gains some way more than others. Dont know of people changing from 300X to the R. I probably will this year on my Twister . I have a 40 hour from new 04/05 300x with a brand new 1.62 from swapping out a 1.75 with carbon pan and cowl going up for sale this summer .

**Double Rigged** · 02-27-2020, 07:17 PM

Keep your 300x. There are advantages of the new motors in fuel mileage, being dock friendly etc. However if you prop your 300x for 7000 max rpm IMO the 300r will not keep up in acceleration. Problem is in order to get the top speed like the test showed you need the 1.60 gear and a large prop as the limit is 6400rpm. The guys at Lake X told me the sweet spot for the 300r is 6250 for max power. 33sec from 40-100 mph is pretty sad considering my boat will do it in around 20 seconds. I have no argument the the 300r is better than a 300xs. All day.