WilliamM Posted May 29, 2014 Share Posted May 29, 2014 Hi,I've got an Aprilia RS 125 (year 2000) model which I've got as a bit of a project. It's my first bike and although I'm going to do the full test this year I won't be able to afford to get a bigger bike for a another year or two so I just got a cheap bike that I could do up and have a bit of fun with.Even though the RS I have is derestricted it is still massively under powered, as i'm sure you can imagine. My question is this - would an RS 250 engine of the same or similar year fit on the bike I have? When I say fit - I mean just literally drop in without any modification to the frame or what have you. This would take the horse power from 34(ish) to 64(ish) which would make a significant difference on a bike that size.I guess I could just sell mine and get 250 which would be a similar price but I like the idea of doing the work myself - all part of the fun.ThanksWilliam Quote Link to comment Share on other sites More sharing options...
Joeman Posted May 29, 2014 Share Posted May 29, 2014 Nope!The rs-250 is basically the Suzuki RGV250 motor.It won't be a direct swap.I've seen 650 single cylinder motors put into 125aprilia frames. Takes a bit of work, but end result is good.Trouble you will have is insuring it. No company will touch a new rider on such a heavily modified machine. Quote Link to comment Share on other sites More sharing options...
WilliamM Posted May 29, 2014 Author Share Posted May 29, 2014 That's a shame - the extra power would come in handy but you make a valid point about insurance as well. Quote Link to comment Share on other sites More sharing options...
Fozzie Posted May 29, 2014 Share Posted May 29, 2014 The RS250 was a great bike, they actually just bought the rights to the engine from Suzuki then meddled with it. So it does have different mountings but it still won't fit in the RS125 frame properly without some major work. The top ends of the engines do fit on each other however the Aprilia top end is more powerful as it was one of the main parts they messed with.The Rotax 257 engine is a direct fit into an RS125. It's a single cylinder and it will make more oomph but you obviously have to source the electrics and carb and then make it all work on your bike. It was originally designed for a go kart. Quote Link to comment Share on other sites More sharing options...
l.t racing Posted June 1, 2014 Share Posted June 1, 2014 Already did this few years ago. Did it with the rotax 257 engine it dose not drop str8 in. You have to bush and space engine on back top mount, make front engine mounts i got some lazer cut and also made some in carbon fiber. Then you have to make bottom engine mounts. If you use a stock 125 rad the pipes are on the wrong side. Your best of getting a one off rad and exhaust pipe like i did. Im on with building my self a rs125 for road but now going to stick a rotax 257 engine in again. Want weight around 90kg and power 60 to 65bhp.lee Quote Link to comment Share on other sites More sharing options...
WilliamM Posted June 3, 2014 Author Share Posted June 3, 2014 Thanks chaps - I guess it's a no goer for me at the moment - I have limited space to be able to do any work and given the effort it's probably just worth trading in for a different bike at some point. Have to try and get the most out of the 125 with a little bit of tuning here and there Quote Link to comment Share on other sites More sharing options...
Classickid21 Posted June 19, 2014 Share Posted June 19, 2014 Nope!The rs-250 is basically the Suzuki RGV250 motor.It won't be a direct swap.I've seen 650 single cylinder motors put into 125aprilia frames. Takes a bit of work, but end result is good.Trouble you will have is insuring it. No company will touch a new rider on such a heavily modified machine. ive seen Rd 350 ypvs engines in Cagiva mitos online and Kx500 in a mito 125 frame so anything is possible with the right tools and right cash i did consider putting my 300cc rotax single in a Rs 125 then i had my doubts etc Quote Link to comment Share on other sites More sharing options...
Classickid21 Posted June 19, 2014 Share Posted June 19, 2014 Hi,I've got an Aprilia RS 125 (year 2000) model which I've got as a bit of a project. It's my first bike and although I'm going to do the full test this year I won't be able to afford to get a bigger bike for a another year or two so I just got a cheap bike that I could do up and have a bit of fun with.Even though the RS I have is derestricted it is still massively under powered, as i'm sure you can imagine. My question is this - would an RS 250 engine of the same or similar year fit on the bike I have? When I say fit - I mean just literally drop in without any modification to the frame or what have you. This would take the horse power from 34(ish) to 64(ish) which would make a significant difference on a bike that size.I guess I could just sell mine and get 250 which would be a similar price but I like the idea of doing the work myself - all part of the fun.ThanksWilliam Hello William Sounds like a great plan i have a rotax 295/300cc Fully running gears loom etc if you'd be interested in that single barrel engine same size engine as the Rs 125 if you was interested in doing that idear i could possible get you may photos of the mountings Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.