# Restrictor plate removal



## State fish rob

Has anybody removed the restrictor plate from an EFI engine for more horsepower. Is this something doable or is this just a crapshoot. Speaking Particularly about a Yamaha F 50 take the plate out and supposedly it’s a F 60. Seems too simple


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## State fish rob

Come on guys , why the crikets ? Just asking ,not judging


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## Smackdaddy53

I bet boatbrains knows. Of not maybe call Chris Carson’s shop.


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## eightwt

I don't know, but some modifications can void warranties I believe.


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## Elusive Porpi

I have done it. Purchased a new F50 yamaha in 2013ish. It was super simple to remove. Gained 500 RPM's from original setup. Didnt affect the outboard for as long as I owned it. (2 more years)


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## Guest

Go for it! This motor has a map sensor! Fuel injectors are the same, sensors are the same, all specs are the same. The map sensor, tps, control fueling and timing. Timing is 1degree less in the 60 which is probably to make up for the extra air! Just running 89-93 octane should clear up any pre-ignition issues. Run it for 20hrs with a new set of plugs and pull and inspect them.


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## State fish rob

Elusive Porpi said:


> I have done it. Purchased a new F50 yamaha in 2013ish. It was super simple to remove. Gained 500 RPM's from original setup. Didnt affect the outboard for as long as I owned it. (2 more years)


Thats the year ive got Thx for input.


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## State fish rob

Boatbrains has given me the go ahead as well. Specs line up w a 1° difference in timing. Quick 20% in hp. Thx to all 
Im sure this isnt the only efi that has a restrictor plate. Bet all those 90 hp s are really 115 s in disguise! Maybe my 150 ‘ rude is really a 225 !!


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## Guest

State fish rob said:


> Boatbrains has given me the go ahead as well. Specs line up w a 1° difference in timing. Quick 20% in hp. Thx to all
> Im sure this isnt the only efi that has a restrictor plate. Bet all those 90 hp s are really 115 s in disguise! Maybe my 150 ‘ rude is really a 225 !!


Not so fast lol! Big difference between 150-225! Some 90’s are quite capable of 115 but not all. Just don’t wanna confuse anyone lol!


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## Mike C

Since we're on that subject...
I've got a 2008 TLR 60 Yamaha 4s.
Does it have any restrictor type plate on it?


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## Guest

Mike C said:


> Since we're on that subject...
> I've got a 2008 TLR 60 Yamaha 4s.
> Does it have any restrictor type plate on it?


The f70 has a different intake part number, I am guessing a larger throttle body is the only difference so if one were to swap an intake assembly from a bad f70 powerhead then it should work. I’ll compare the other data in a bit. They are the same displacement!


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## Guest

Same injectors!


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## Guest

Ok, my books stop at 06’ but the f75 timing is at 17* the f60 [email protected]* and the f50 @25*. Not sure how you would overcome that much timing difference without an emm/ecm swap also. But if one were to buy a bad motor for parts it would probably have the emm/ ecm.


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## State fish rob

Boatbrains said:


> Not so fast lol! Big difference between 150-225! Some 90’s are quite capable of 115 but not all. Just don’t wanna confuse anyone lol!


My bad , stirring the pot


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## Guest

And for legal purposes...
Boatbrains or his real life alterego will not be responsible for any injury, engine failure, or loss of property whatsoever for offering presumptual insight on any high performance upgrades to any engine, vessel, or any other mechanized/non mechanized tranportation devise such as but not limited to... boats/ watercraft automobiles, trailers, tractors and other equipment, aircraft, etc... any and all shenanigans is solely the responsibility of the person/persons performing such shenanigans no exceptions/ no excuses!


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## Guest

State fish rob said:


> My bad , stirring the pot


Stir away! That’s how we make things faster! Well that and turbos, superchargers, and nos!


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## jimsmicro

I've always wondered what the difference was between the F60 and F70 so I'm going to follow this thread and hope for more info. I feel like you'd need more than just more air, you'd have to have more fuel too, but maybe the computer can compensate automatically?


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## Guest

jimsmicro said:


> I've always wondered what the difference was between the F60 and F70 so I'm going to follow this thread and hope for more info. I feel like you'd need more than just more air, you'd have to have more fuel too, but maybe the computer can compensate automatically?


The emm compensates via the map sensor and holds injectors open longer which equals more fuel.


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## Smackdaddy53

Boatbrains said:


> The emm compensates via the map sensor and holds injectors open longer which equals more fuel.


ECM eh?


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## FSUDrew99

Anyone know of any aftermarket tuning for mid sized motors aka zuke 60 that are worth a damn or being such a small and naturally aspirated motor the juice wouldn't be worth the squeeze?

Id love to see the equivalent of a Nizpro supercharger for a 60/70 hp on up not just a Yamaha 250 sho...


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## Guest

FSUDrew99 said:


> Anyone know of any aftermarket tuning for mid sized motors aka zuke 60 that are worth a damn or being such a small and naturally aspirated motor the juice wouldn't be worth the squeeze?
> 
> Id love to see the equivalent of a Nizpro supercharger for a 60/70 hp on up not just a Yamaha 250 sho...


I wish there were more r and d for these <115 hp engines. The problem is this...
The cost of the parts would be extreme compaired to the cost of the outboard and the public wouldn’t want to spend >$3k on a supercharger for their f70. It would also add weight and as you know, that’s baaad on a microskiff. How about an integral turbo charger built into the exhaust tuner???


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## yobata

Boatbrains said:


> And for legal purposes...
> Boatbrains or his real life alterego will not be responsible for any injury, engine failure, or loss of property whatsoever for offering presumptual insight on any high performance upgrades to any engine, vessel, or any other mechanized/non mechanized tranportation devise such as but not limited to... boats/ watercraft automobiles, trailers, tractors and other equipment, aircraft, etc... any and all shenanigans is solely the responsibility of the person/persons performing such shenanigans no exceptions/ no excuses!


What about a jetskies?


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## Guest

yobata said:


> What about a jetskies?


Covered under the watercraft provision already in place, no ammendment needed lol!


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## yobata

Boatbrains said:


> Covered under the watercraft provision already in place, no ammendment needed lol!


I was hoping for something more along the lines of: "Those guys get what they deserve"


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## Guest

yobata said:


> I was hoping for something more along the lines of: "Those guys get what they deserve"


That would probably void my disclaimer and move any charges to pre meditated and the I’d be farked!


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## LowHydrogen

Have you guys ever looked at any of the Aussie outboard motor modification sites. They mod the hell out of small outboards down there and race em. I think they have the outlook that's like, everything else down here will kill you, let's get small tiller motors in that category as well lol.

Look up bass machines tohatsu


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## Smackdaddy53

LowHydrogen said:


> Have you guys ever looked at any of the Aussie outboard motor modification sites. They mod the hell out of small outboards down there and race em. I think they have the outlook that's like, everything else down here will kill you, let's get small tiller motors in that category as well lol.
> 
> Look up bass machines tohatsu


Hell yeah those tin skiff races are crazy! Dude in front leaning into turns...


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## FSUDrew99

My buddy's uncle has a 20' Lake and Bay with the 20 sho and a 200 hp nizpro supercharger.....

Race lower unit and a 32 pitch prop was getting 101.4 mph in the river.....

Since then they have beefed it up even more....


Forced induction is always the way to go for serious power gains as always.

I agree the supercharger kits for smaller motors would be half the cost of the motor plus add another 40-50 lbs to the overall motor id guess.. they are too crazy (pulleys, new manifold, etc) get some cowling spacers and plug and play....


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## Guest

Now waiting patiently for this to turn into an environmental thread with all the engine mods mentioned!


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## jonrconner

Boatbrains said:


> I wish there were more r and d for these <115 hp engines. The problem is this...
> The cost of the parts would be extreme compaired to the cost of the outboard and the public wouldn’t want to spend >$3k on a supercharger for their f70. It would also add weight and as you know, that’s baaad on a microskiff. How about an integral turbo charger built into the exhaust tuner???[/QUOTE
> 
> I fail to understand why turbochargers aren’t ubiquitous on the new four strokes, the hp/displacement ratio is so good and the weight penalty is so low and spin up time would not be a problem. They’ve had them on chainsaws for a long time.
> JC


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## Guest

I wish they would myself! Their engineers are brilliant and the r and d budget is pretty liberal! I don’t know that the juice would be worth yhe squeeze as they would still have to have beefy lower units and such. You could easily turn a 30 into a 50 with about 5-7 psi and proper fuel map! But not sure the weight savings in the power head alone would provide signifigant gains all around? It’s still fun to ponder! I know what can be had with a two stroke with some fuel/air, porting, and exhaust mods!


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## Guest

I have a 40/50 omc from 98, I am estimating around 70 hp output when complete! Mods are pretty basic including big carbs and jetting, custom carb spacers, fiber reeds, serious tuner work, port tuning, solid wrist pin, milled 50 cyl head, custom designed power head exhaust expansion chamber, idle relief ports plug welded from back side to increase compression, and a few more tweaks lol! This is gonna be for an outboard jet so after powerhead is complete I get to play with a pump lol! Outboard jets said no don’t do it because the medium pump won’t hold it, but I will have the stainless impellor modded to flow the water properly “jet ski crap” and should be good! She’s gonna be an av gas queen for sure, but will be a screamer “which, me likey a screamer”!


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## Smackdaddy53

Boatbrains said:


> I have a 40/50 omc from 98, I am estimating around 70 hp output when complete! Mods are pretty basic including big carbs and jetting, custom carb spacers, fiber reeds, serious tuner work, port tuning, solid wrist pin, milled 50 cyl head, custom designed power head exhaust expansion chamber, idle relief ports plug welded from back side to increase compression, and a few more tweaks lol! This is gonna be for an outboard jet so after powerhead is complete I get to play with a pump lol! Outboard jets said no don’t do it because the medium pump won’t hold it, but I will have the stainless impellor modded to flow the water properly “jet ski crap” and should be good! She’s gonna be an av gas queen for sure, but will be a screamer “which, me likey a screamer”!


You’re sick like me!


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## Guest

Smackdaddy53 said:


> You’re sick like me!


It’s a disease really! I wonder if I would qualify for disability lol?


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## Guest

Do ya think Jack Foreman would play with an impeller


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## Smackdaddy53

Boatbrains said:


> Do ya think Jack Foreman would plat with an impellor?


Possibly but he may also give you an ear ful. He’s a trip.


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## Guest

Smackdaddy53 said:


> Possibly but he may also give you an ear ful. He’s a trip.


I’m used to getting an ear full lol! Hell, I tell people I’m gonna build skiffs and all they say is get ready to go broke! Oh well, that’s another thread! Back to horsepower talk and killin dinasaurs!


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## Guest

Did ya’ll know when the Verado came out the 200-275 platform was capable of over 400 hp but the gearcases wouldn’t hold it?


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## FSUDrew99

A simple program with changes in timing, air/fuel ratio on the EFI motors alone will push some ok power but that supercharger though..... 

I can hear the whine from here!


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## Guest

FSUDrew99 said:


> A simple program with changes in timing, air/fuel ratio on the EFI motors alone will push some ok power but that supercharger though.....
> 
> I can hear the whine from here!


Whine/whistle, who cares? They both sound SEXY!


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## Guest

Well shat! I have a small turbo off a little 4cyl car and now ya’ll got me thinken, why not? I will have to plumb an electric oil pump and cooler to lubricate it. But a turbo scavanged two stroke two cylinder? Well that just sounds leathal!


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## jonrconner

Boatbrains said:


> Well shat! I have a small turbo off a little 4cyl car and now ya’ll got me thinken, why not? I will have to plumb an electric oil pump and cooler to lubricate it. But a turbo scavanged two stroke two cylinder? Well that just sounds leathal!


It might actually be feasible with a turbo from a motorcycle of about the same displacement or maybe smaller, bike’s redline tends to be way up there compared to outboards. The great thing about a turbo motor is the huge torque produced at low rpms, out of the hole power would be amazing once you figure out how to get the timing of the turbo spin up.
JC


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## State fish rob

I saw a site where they were pushing exhaust mods. Exhaust gas exits before i reaches the prop. Could go either way , like muffler cut offs on a truck. 
All this voodoo with motors reminds me of when i ported and polished my little brothers moped (For you young guys think scooter with pedals) that thing would hit 65mph on flat ground Those were good times


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## Mike C

Well, sheeeyit. I was hoping for some nearly free horse power. 

How much fun it would be to have the time and funds to play with a 60 and try to get 90+ hp out of it. 
My Tailfisher would probably hit 40mph instead of 31.
That hull would be scary as hell running the creeks and sliding all over the place.


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## FSUDrew99

Boatbrains said:


> Well shat! I have a small turbo off a little 4cyl car and now ya’ll got me thinken, why not? I will have to plumb an electric oil pump and cooler to lubricate it. But a turbo scavanged two stroke two cylinder? Well that just sounds leathal!


Sounds badass...... maybe have a cowling cutout with some turbo showing like a drag car hood haha.

I bet if it is small enough that small outboard motor will produce enough exhaust to get her rolling.. not like you have to shift gears or anything and restart the power band!


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## FSUDrew99

Or go full retard and run this same turbo desiel air cooled long tail setup, but with a true lower unit!.....
Rolling coal!!!!


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## No Bait / Lures Only

jimsmicro said:


> I've always wondered what the difference was between the F60 and F70 so I'm going to follow this thread and hope for more info. I feel like you'd need more than just more air, you'd have to have more fuel too, but maybe the computer can compensate automatically?





jimsmicro said:


> I've always wondered what the difference was between the F60 and F70 so I'm going to follow this thread and hope for more info. I feel like you'd need more than just more air, you'd have to have more fuel too, but maybe the computer can compensate automatically?


F70la has sohc 4 valves per cylinder n 6300 max rpm, 9.4:1 comp ratio, 2.33 monster lower unit. N yes it is same cubic inches as 50, 60, Yamaha's.


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## Jason

What about a 2005 Yamaha 60tlr two stroke? Any chance of an easy bump to 70?


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## Guest

A 60 can be made to make 70hp. It’s all about air/fuel in and exhaust out! It would require carbs, reed stops, cyl head shaving, and exhaust tuner.


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## Jason

We’ll just wait and hang the right power on next skiff! Lol


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## Guest

Jason said:


> We’ll just wait and hang the right power on next skiff! Lol


Or, if all part numbers are the same you could find a donor motor with a blown PH or LU and scab parts from it!


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## PeterTrudie

Hi I know this is an old thread but I have been reading through it with interest. I recently purchased a DF15 efi Merc and it has a restricter and the 10hp has a smaller restriction, can anyone tell me if removing the restrictor will cause any harm?
Regards


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