[This TOPIC broke out in another thread in which an upgrade of a 30-HP engine to become a 40-HP engine was mentioned as part of a boat restoration project. This new topic has been separated from the original discussion—Moderator.]
How did you "upgrade " the 30 HP engine to 40 HP?
Upgrade 30-HP to 40-HP
Upgrade 30-HP to 40-HP
Butch
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jamesnovak
- Posts: 15
- Joined: Sun Aug 30, 2020 3:23 pm
Re: Upgrade 30-HP to 40-HP
The previous owner [upgraded the engine]. The marina tells me [the upgrade to 40-HP from 30-HP is] simply a restrictor plate change[.]
Re: Upgrade 30-HP to 40-HP
Please find out and provide the restrictor plate part number and source. I'm sure I'm not alone in wanting to upgrade my engine HP by 33% by such a simple upgrade.
Butch
Re: Upgrade 30-HP to 40-HP
The 30 and 40 are not even the same engine. I have never seen a restrictor plate on an outboard before either. Somebody made that up.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).
Re: Upgrade 30-HP to 40-HP
The older 2 stroke power cycle engines could often be upped in HP. Johnson and Evinrude back in the 1970s and 1980s made a block that could be bought in a 20, 25, 30 and 35 hp. The difference was the intake and reed as well as some carburator changes. I owned a 20 hp version but started to gather the parts needed to up the hp from eBay. I sold the boat with the parts before I had the time to do the swap of parts.
Re: Upgrade 30-HP to 40-HP
This topic--how to get a very easy improvement in engine horsepower output from a simple mechanical change--has been around for decades. But I still cannot recall any first-hand account of it actually being done and some actual data provided that demonstrated improved horsepower. In this thread we have a second-hand account that someone else performed the upgrade, no evidence that there was an improvement in horsepower, and another second-hand account of removal of a restrictor plate.
Older outboard engines without any sort of sophisticated control by microprocessors and stored algorithms tended to always have some sort of mechanical difference between engines of similar displacement, similar engine block, and similar carburetors. These are engines made 20-years ago or older. I don't think there is an intense interest in learning how to improve the power output of these old carburetor engines.
The whole topic arose from an offhand mention of such an upgrade in a thread that was really not focused on that topic. Perhaps we should let this thread end as all others on the topic have, quietly and with no proof of any actual improvement in power output.
Older outboard engines without any sort of sophisticated control by microprocessors and stored algorithms tended to always have some sort of mechanical difference between engines of similar displacement, similar engine block, and similar carburetors. These are engines made 20-years ago or older. I don't think there is an intense interest in learning how to improve the power output of these old carburetor engines.
The whole topic arose from an offhand mention of such an upgrade in a thread that was really not focused on that topic. Perhaps we should let this thread end as all others on the topic have, quietly and with no proof of any actual improvement in power output.
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jamesnovak
- Posts: 15
- Joined: Sun Aug 30, 2020 3:23 pm
Re: Upgrade 30-HP to 40-HP
On a different forum and about a Mercury three-carburetor FOURSTROKE.
[Bad url removed. Please do not post links that do not work—Moderator.]
This is a very easy upgrade and costs about $15. All you have to due [sic]is pull the carbs and spacer and replace the isolator with the 40 one(#834784T) as the 30 has smaller holes (restricter plate)
[Bad url removed. Please do not post links that do not work—Moderator.]
Re: Upgrade 30-HP to 40-HP
A non working link is the perfect ending to this thread.