Throttle checked for full travel... see how it goes tomorow when I go get it wet
I just bought a small inflatable boat... came with a 2004 9.9hp engine. Its a 250cc 2 cyl 2 stroke....
There is a sticker on the engine block that says something along the lines of "this engine has been officially de-restricted"
This appears to be common practice to meet emissions in some countries... the engine is identical to the 15hp version they sell....
User manual says that 9.9hp occurs at 5500RPM on the 9.9hp engine.... and 15hp occurs at 6000rpm on the 15hp engine...
Now I can see a shiny tin plate between the carb and the engine block... so I assume this is the restrictor... but could there be anything else done
to restrict it that might need to be removed? If I remove the restrictor will I need to re-tune the engine etc?
If it's been officially de-restricted doesn't that mean it has had the restriction removed? Is it the reed plates you can see? If you remove them it will not work as there will be no crank case pressure.
As above reed valves, don't even touch them, very fragile and required for the combustion process.
quote:
Originally posted by tegwin
I just bought a small inflatable boat... came with a 2004 9.9hp engine. Its a 250cc 2 cyl 2 stroke....
There is a sticker on the engine block that says something along the lines of "this engine has been officially de-restricted"
The restrictor usually takes the form of a device to prevent the carb slide fully opening, or a reducer in the exhaust port.
Sorry... typo... the engine plackard says it has been "restricted"... I want to de-restrict it...
Whatever mods they did to drop the 15hp to a 9.9hp can not have been too complicated. Adding a restriction on the exhaust would be very tricky... but
putting one on the intake, very easy....
I did a Mercury engine that was restricted to under 10hp for those countries where you need a license to use a craft with anything more powerfull. The restriction consisted of an orifice plate between the carbotooter and the reed valve housing and there was a little plastic clip on the throttle stop. These were rehomed in the hedge and it went like stink!
Well I went over the engine with my detective hat on and the only thing I could find was the restrictor plate on the inlet.... Teeny tiny hole in the
middle of a massive opening... so that has now been slung in the bin...
Throttle checked for full travel... see how it goes tomorow when I go get it wet
Lol. Go for it! 
cool ! locost styleeee 
Christ almighty... 15hp on a tiny little inflatable boat... damn scary... 
Had much fun at the weekend.. although I ache :p
quote:
Originally posted by tegwin
Christ almighty... 15hp on a tiny little inflatable boat... damn scary...
We have a small inflateable (about 9ft long) with a 7.5hp on it and it FLIES once it gets on the plane.