S-25 and F4.1 engines

[OfnaHyper]

Hey guys.

Is there any difference between the S-25 engine and the F4.1 engine? Do they produce the same power and what is the RPM range of each? I have both and are debating which one to use. From what I can tell the only major difference is the F4.1 is alot heavier. I prosume the F4.1 replaced the S-25 when the original SS kit was discontinued.

Any feedback as always much appreciated.

 

[Racer 1966]

According to HPI,the F4.1 is an upgrade from the S.25. Supposedly has more power and torque. I haven't had one myself,that's from HPI literature.

 

[OfnaHyper]

Yeah. After posting this I checked on the HPI website. They claim the S-25 to have 2.5HP and the F4.1 to have 2.75HP. Can't see that making a massive difference though, could be wrong.

 

[Newb86]

for the power to weight ratio i think there will be a noticeable difference alittle more torque and maybe acouple mph gain if your running same gearing with both

 

[NCNitro]

I can't speak personally about the 4.1 as I have never had one, but the S-25 in my original SS is still running strong and still runs like a raped ape.

 

[MudSlinger33]

Runs like a raped ape? Interesting...

 

[NCNitro]

LOL, yep. My S-25 owes me nothing, It can sit for months, I'll fuel it up, prime it, and she will always start within two to three pulls.

 

[Racer 1966]

My original 25 is still going strong too. I got tired of waiting for it to die so I just swapped it out for the fun of a bigger engine. I have new home in the works for it,just not sure when I'll get to it.

 

[NCNitro]

I actually had taken mine out a while back, putting in what I thought would be a better mill, an Ofna/Picco 26, but I liked the way my S-25 ran much better, so I ended up putting the S-25 back in and selling the Ofna, and never looked back.