l3ddy Posted December 4, 2013 Report Share Posted December 4, 2013 Im pondering wether to stick a big thumping single into my aprilia rs125 race bike this winter. Have read lots of build threads and done plenty of searching on which engine to use but I thought I'd ask on here to get a few opinions. The Ktm lc4 engine looks the best bet but i reckon I'm looking at around a grand for the motor on its own, which is expensive for a winter project of hacking and grinding things up to me. Cheaper option is aprilia pegaso 650 but I don't think I've seen one of these fitted only read about them been done. My main problem is the engine has to have a right hand side sprocket otherwise I'd be looking into the modern mx engines. Any advice or ideas would be greatly appreciated! Link to comment Share on other sites More sharing options...
porter_jamie Posted December 4, 2013 Report Share Posted December 4, 2013 you racing? imo there is only one choice, 690 ktm. if not then whatever you can get your hands on. i think the pegaso has wierd ass conical cams or somethign which is why it is never used for racing. it is the same as a bimmer under the head gasket they tell me. bimmer is a fine choice. something to think about - chain on a bimmer and a rotax is on the right hand side. (and presumably the priller) Link to comment Share on other sites More sharing options...
Majik Posted December 4, 2013 Report Share Posted December 4, 2013 CCM 644 (Suzuki Freewind/DR650) motor goes in my Goose in the next few weeks. I reckon it's as compact as it gets, plus 50ish BHP as stock. Cheap as chips to pick up too. Link to comment Share on other sites More sharing options...
Superdunc Posted December 4, 2013 Report Share Posted December 4, 2013 The 640lc4 can be had for @£500 with careful shopping around. I sold an early640 with ancillaries for £250 a few years back . Try and get the grey Hi flow motor. The 690 lc4 s the daddy, but pricey. Wouldn't entertain anything else except the BMW 650 at a push. Link to comment Share on other sites More sharing options...
wazrs257 Posted December 4, 2013 Report Share Posted December 4, 2013 CCM 644 (Suzuki Freewind/DR650) motor goes in my Goose in the next few weeks. I reckon it's as compact as it gets, plus 50ish BHP as stock. Cheap as chips to pick up too. The chain's on the left though, isn't it? My stock answer in cases like this is, fuck the four stroke idea off and get a Rotax 257! Link to comment Share on other sites More sharing options...
l3ddy Posted December 4, 2013 Author Report Share Posted December 4, 2013 Sorry should of mentioned, it will be used for track days but the main reason is to keep me busy over the winter months! Looks like I may have to stump up for a Ktm motor then. Fancy something different to the 2 strokes I have had for the past few years waz. Thanks for all the replies too Link to comment Share on other sites More sharing options...
porter_jamie Posted December 4, 2013 Report Share Posted December 4, 2013 690 chain on left, 640 chain on right. 690=6 speed 640=5 speed Link to comment Share on other sites More sharing options...
l3ddy Posted December 4, 2013 Author Report Share Posted December 4, 2013 Where else should I look apart from eBay? Never really hunted for an engine before and there isn't much choice on the bay that will leave me with change from 1k. Thanks for all the help Link to comment Share on other sites More sharing options...
Superdunc Posted December 4, 2013 Report Share Posted December 4, 2013 Buy something like this for £1100 ish, or maybe something a little scruffier http://www.ebay.co.uk/itm/ktm-duke-/161163705331?pt=UK_Motorcycles&hash=item25861afbf3 Everything you need, you can check the motors sound and ebay the rest for £400-500. Link to comment Share on other sites More sharing options...
porter_jamie Posted December 4, 2013 Report Share Posted December 4, 2013 i think ducan has the best idea - buy a whole bike you have everything then even a battery Link to comment Share on other sites More sharing options...
wazrs257 Posted December 4, 2013 Report Share Posted December 4, 2013 That sounds like a plan. You may even be able to fit the standard pipe inside the frame and have twin pipes exiting under the seat! Link to comment Share on other sites More sharing options...
Alex_H Posted December 4, 2013 Report Share Posted December 4, 2013 ccm 604e rotax lump has the chain on the right hand side, good simple motor, should be plenty about. Link to comment Share on other sites More sharing options...
porter_jamie Posted December 4, 2013 Report Share Posted December 4, 2013 i can sell you a 72rwbhp rotax engine with billet cases and 40mm inlet valves for eighten gasquillion pounds if you like. and i'll throw in the black keys for free etc. Link to comment Share on other sites More sharing options...
spacemonkey Posted December 4, 2013 Report Share Posted December 4, 2013 That sounds like a plan. You may even be able to fit the standard pipe inside the frame and have twin pipes exiting under the seat! You can with a Pegaso engine on the AF1 so you may well be able to on the RS125. Link to comment Share on other sites More sharing options...
l3ddy Posted December 5, 2013 Author Report Share Posted December 5, 2013 Been offered a pegaso engine, loom, cdi, carbs etc all for 240 posted to my door. I know it wasnt the first choice mentioned but I am tempted, or should I wait out for a Ktm one? Link to comment Share on other sites More sharing options...
porter_jamie Posted December 5, 2013 Report Share Posted December 5, 2013 sounds like a bargain. try and get the headers as well Link to comment Share on other sites More sharing options...
l3ddy Posted December 5, 2013 Author Report Share Posted December 5, 2013 Yep exhaust headers included aswell basically the whole lot but I said I didn't want the airbox or the rad and he knocked a little bit off the price. Only thing I'm concerned about is these are twin carb as appose to the lc4 which is a single carb. Just going to be abit more room taken up, and the ones on YouTube seem to be running a custom fuel tank under the seat unit. All part of the fun I guess, do appreciate all the helpful replies! Hopefully get it snapped up and a build thread up soon Link to comment Share on other sites More sharing options...
Superdunc Posted December 5, 2013 Report Share Posted December 5, 2013 Make sure you get the CDI and all the wiring. I seem to recall there is a silly factory immobilizer on these that can be a faf if you mix bits from different bikes. Otherwise you can't loose at that price. Link to comment Share on other sites More sharing options...
wazrs257 Posted December 5, 2013 Report Share Posted December 5, 2013 Only thing I'm concerned about is these are twin carb as appose to the lc4 which is a single carb. Just going to be abit more room taken up, and the ones on YouTube seem to be running a custom fuel tank under the seat unit. With a 4-stroke you will struggle with room under the standard tank. There should be enough space to fit a small custom made ally tank under standard tank cover though. This is my plan when I fit a nice big airbox to my 257. Link to comment Share on other sites More sharing options...
l3ddy Posted December 5, 2013 Author Report Share Posted December 5, 2013 Spent another day reading into the pegaso conversions because I'd only seen the Ktm ones to begin with. The carbs hitting the tank seem to be the major hurdle as you say, some people have modified the plastic tank, others altered the inlet so the carbs sit lower. Guess I'll have to work it out once it's fitted in the frame Link to comment Share on other sites More sharing options...
porter_jamie Posted December 11, 2013 Report Share Posted December 11, 2013 http://www.ebay.co.uk/itm/Aprilia-Pegaso-650-1997-Engine-Package-Carbs-Exhaust-Loom-CDI-Supermono-Go-Kart-/301028145941?pt=UK_Motorcycle_Parts_13&hash=item4616acfb15 Link to comment Share on other sites More sharing options...
l3ddy Posted December 11, 2013 Author Report Share Posted December 11, 2013 That's the one I was offered at a cheaper price than advertised. The more digging I did though I just came to the conclusion that using the Pegaso tank meant I had to make a custom fuel tank as the twin carbs stick so high up in the frame and also its a dry sump engine so an oil tank would need to be fabricated and crammed in somewhere! The Ktm engine seems such a better option once I did more research. Link to comment Share on other sites More sharing options...
kaighn80 Posted December 11, 2013 Report Share Posted December 11, 2013 Ktm is the better option by far, that's what I'm doing and not just because I have one.Ktm is the better option by far, that's what I'm doing and not just because I have one. Link to comment Share on other sites More sharing options...
CRMotard Posted December 13, 2013 Report Share Posted December 13, 2013 If you want to add 40kgs to your bike just get a pillion! If you want to make it unreliable, just put some swarf down your plug hole. Both of the above suggestions cost nothing or alternatively you can spend a heap of money putting a junker 4 stroke motor into a perfectly good bike. same result either way Just sell it and buy an szr660 or swap your motor out for a Rotax 128. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.