Performance Improvements possible with newer 4 stroke outboards
Up here the new generation of racers are not interested it the old school 2 stroke motors. They would like to use their lap top and reprogram their motor same as they do with their cars. They don't mine throwing lots on money into their modifications. There is a very good supply of rebuildable 4 stroke outboards on the market for them to work with. The problem is there is limited information on what can be done to improve the performance or any OEM or aftermarket parts. Maybe there is not enough market for companies to spend the R&D money necessary to develop the products. Years ago the same could be said about the small Honda cars.
To-day that is a BIG business.
We need find ways to get these new people racing. Are you seeing the same thing in your area?
Any suggestions?
Hounddog, You And I Are A Lot A Like
I spent Saturday going over spec sheets "PAWING OVER" A Mercury four stroke head. Simon Motor Sports in San Diego has figured out how to, I think the word is "Flash" the computer, so they can disconnect the revlimiter.
But the motors will still only turn 6,500 RPM's.
My "PROJECT" is "Top Secret" right now, but I will tell you there are many areas that the Mercury 40-60 four stroke can be improved.
I will be "Up Front" with you. The head looks like the flow may well be restricted on purpose. (Need to sell better running motors in the future, you know built in obsolescence).
The value springs may be too weak, and allow the values to "FLOAT".
The exhaust area of the exhaust ports appears to be "Squeezed" down, this me be for pollution reasons, or just planned horse power control.
"My People" are going to run the numbers, and figure out what the cam is and what they think the cam should be.
At this time, I have no plans to market anything for these motors. I am working as a "MIDDLE MAN" with some people than want improved performance and they have the financial backing needed for some development work.
I just wish for you guys in Canada, would look at Texas, Tri Hull's roll cages. Or go to 660 drags. Todd Bucknell's accident, last summer, was not got for boat racing!
I have no "FACTS" other than hear say, but It appears the NEW Tohatsu four stroke has some real power. I have 18 pitch props running on 30 HP Tohatsu four strokes and hitting the rev limiter.
Simon Motorsports of San Diego, California
I have heard, that Simon Motor Sports can "FLASH" the ECU on Mercury 40-60 HP. http://www.simonmotorsports.com/ I'll admit, I don't know what an ECU is. I do know what a rev limiter is.
I've talked to them on the phone, super polite and helpful, though I didn't have very clear questions.
Schneider Race Cams in San Diego Knows Cams
Quote:
Originally Posted by
Tiller guy
I'm sure someone knows how to work those heads. It would be a fun project to play with.
I think his name is Jerry. Been grinding cams since the Kenny Harmon days. Kenny welded cam's lobs on 250 Honda Motorcycles and then re ground them. Lit those 250's up. Jerry regrinds the cams and sells valve springs. We gained 10% with this cam on a 40 HP.
Flashing the computer helps ZERO UNLESS THE VALVE SPRING ALLOW HIGH RPM'S.
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Ron Hill is A Two Stroke Man, and Always Has Been and Always Will Be!
The problem with 2 strokes, right now, there are no new one in America. And they haven't made any for 15 years or so.
The people I deal with race hard in drag racing with their two strokes, but they do blow engines up and parts are getting harder to find.
Guy buy new four strokes, put them on a boat that went 50 MPH and the new Four Strokes go 42 MPH. With the help of the Signature Propellers we have been making, we have the speed up 12 MPH.
Looking the heads over, figuring compression ratios, porting the heads, grinding the cams, changing the valve springs, we will gain power!
For how long? That is the question!
Prop looks somewhat like this, but this is not the "HOT PROP" for 50 HP 4 strokes.
"IF EVINRUDE" Since 1966 I've Been Saying That...
Go with a winner and Mercury and Yamaha are the winners....well Tohatsu has some "hot" 40-50 HP four strokes with that 2.23 gear ratio...But with Evinrude, let's just say "If Evinrude"....
Look on Facebook for Kent Foreman, Foreman Marine. He seems to win all the races.
But We Have Propellers...
Quote:
Originally Posted by
Powerabout
but you had gears....
When my dad worked my props, my best props were "Shifters". They crowd in Seattle have figured this out in kneel down racing.
Honda 50 HP! Made maybe 100 hours since the cam is in there
One of my customers claims a re ground cam helped his Honda, noticeably. He has a 100 hours on the cam.
From second hand information via Mercury Marine, all their smaller 4 Stokes are tamed way down, so they can sell you newer, more powerful ones later.
I do know the early Yamaha 4 Stokes were "Weak Sucks". BUT THE NEWER ONES SEEM TO HAVE SOME LOW AND AND TOP IN GRUNT.
My Customers Have Said, "No improvement" by Flashing the Computer
Quote:
Originally Posted by
twzted
If there was a package I'd buy it but once you start messing with Cam duration and what not a special tune would need to be made I would think, Simon performance does have a tune for the Merc 60, boosts up low mid range power pretty good, and supposedly adds about 5-7 hp where it supposedly makes around ,68 at 6300 rpm, that puts it over 70.i have been trying to find someone who has used their tune to get a real world answer. It's 650$ and for it to do nothing would be a waste and could buy more props. I have a merry 12x22 cleaver Which I believe will be a bit big for my boat but if it's tuned it may work perfectly.
I have been told that them motors still won't rev, and the valve spring are too weak. With a re ground cam and heavy duty spring, "FLASHING" the computer helped a lot.