So im basically a n00b on here, so sorry if this is repetitive or redundant!
Ok so i bought a 93 Suzuki gs500(e im guessing) about a year and a half ago for $100 with title and all. It was a complete bike and looked decent but....the engine was completely destroyed, top to bottom. I knew it was blown but i thought i could at least salvage the bottom end, but thats not the case sadly, it threw a rod and the piston itself into the gears.
Soooo i got discouraged, partly because i bought a kawasaki H1, partly cause i felt it was a hopeless project... but the other day i got hit with the bug and wanted to start it up again.
Soo my main questions are:
1. Really want to put a motocross motor in it (preferably cr250 and two stroke, for weight and ease) Has this been done that anybody knows of (again, noob, didnt scavenge through the wasteland of threads just yet)
2. Forks/Seals are trashed, ive seen on here a GSXR front end swap, would like a straight up no bs answer about the easiest/best year to use
3. Reallllly really want a motocross engine in this!!! Spare me the "dont do it cause youll have to carry premix everywhere" or "get used to pickin up your top end pieces every 200 miles" or some bs like that cause ive heard it all haha ive compared some stats off a 96 cr250 (if i remember the year correctly) and it has about 6 more horsepower than the stock 93 gs500, plus the weight difference of engines. *does anyone think this would over power the chassis** Its not that big of a difference and i cant see the 250 2t having substantially more torque (if any more) than the stock engine. And if anybody is wondering 250's have enough stator power to run a few electronics on it, but i would likely need to upgrade
Motocross engines are a dime a dozen around me and spending 150 on a blown top end 250 motor and fixing it is a lot cheaper than ebaying the stock engine.
Pics SOON!! If anyone can give me some constructive advice, id really appreciate it!!!
projects are only limited by the depth of your wallet. if it fits, go for it
wow thats a little spooky ..
i dont wish to do same transplant .. but i do have a cr250 (89) sitting in the shed.. waiting till i have a bit of time to replace some bits... thinking of buying a rolling frame from a guy not far away from me... and have my complete and running gs500 too...
i'll have to sit the cr and complete gs next to each other and see if i can 'mental image' one engine into other frame...
i would think .. as Yama said.. go for it... but be prepared to 'backyard engineer' on the fly for any problems that the actual transplant and attachment may bring up..
and i reckon you know... but a cr250 engine .. or any 2 stroker of that calibre... can be highly strung little beasts .. no big drama really if you familiar with them.. but they really like ON ... or OFF... putt putting around is not good for their temperament!! :thumb:
Yeah this will probably drain me financially, but i can write it off as a school project (mech. engineering major) so i can probably use the shop and some high dollar machines :thumb:
Thank Janx, i have a 00 cr125 and i was trying to picture and get some dimensions cause ,correct me if im wrong, the two engines are similar in size but the 250 might have a bigger bottom end (def bigger top lol) , i just dont know. and i have no clue about the CR's generation changes to the engine. But from what i can tell from my 125, the gs500 mounts and cr125 mounts are actually damn near close. ill know for sure in a few days (hopefully) cause i need to pull the 125 to rebuild the top end anyways so ill see how close.
Ive been talking to a guy who wants to sell me a 93 ktm sx250 for 250 and claims it runs.....not sure what to do. Either wait for a cr250 or try this??
As for other concerns, Im not sure how/what/difficult it is to align the countershaft sprocket to the stock swingarm
ok... having sat both bike nearly side by side .. 2006 GS500f and 1989 CR250r .. here is what i see ..
the overall size of the gs engine is MUCH bigger ..wider/longer/taller .. as far as the block/heads/gearbox goes...
but ... the expansion pipe of the cr motor sticks further forward and wider then the front end and exhaust of the gs motor .. with a 'pretty close' measurement i think it would be hard to fit the pipe within the GS frame .. but if it was out thru the middle of the frame and around the side like modern CR's then the overall engine would be quite a way forward .. meaning the chain length and spacing suitability is gonna be tricky...
my old 89 CR also has a top central spine with framework hanging down to mount engine in... the pictures of a 95 or similar CR show me different setup .. and more like the style of the GS frame... top Y 'spine' and framework hanging down and back to the mounts of the swingarm area... so theoretically easier as far as bolt holes.. or at least being able to fabricate mounting plates to match everything up ...
the airbox/filter system is also a fair bit further back on any CR motor but with some neat and careful adjustments would be 'do-able' ..
overall i think you have to even get hold of a mates motor 'for the weekend' ... blown/wrecked or just spare .. and with the motor out of your GS and the tank off obviously .. just sit the CR motor... or KTM .. Suzuki.. whatever but i'll stick to the CR idea for simplicity in this post.... anyway.. sit it in the GS framework , wiggle it around a little and see whats needed for initial mounting.... THEN .. look at where your drive sprocket needs to be for the GS frame... adjust the motor and see if it can be still mounted in somewhow... (the gearbox width of my CR is around 4 inches NARROWER than the GS box and would be a bastard to shift the motor that far left!!) .. it depends on the relative dimensions of the donor motor.. the newer ones may be much fatter and closer for alignment..
with most of the modern 2 stroke engines... and yes even on my old 89 .. they also have water cooling and radiators/hoses/shrouds etc .. which you will also need to figure a suitable location for and allow enough airflow into!!...
everything COULD be do-able .. and once complete and tested/running would be somewhat of a attention grabber!! .. its a good thing you have access to a workshop and are doing engineering.. you gonna need it bro!!... ;) ... with the right tools and equipment and knowledge base its a fairly straighforward PROCESS .. but determining the REQUIREMENTS and MODIFICATIONS for the process to complete is the tricksy bit!!
personally .. with the tools and mates and space "I" have available... i wouldnt touch it!.. noooooooooooo!!!... but with the backup YOU have... well hell!!!... go hard young fella!! .. :thumb:
also... hoping its electric start 2 stroke you get... the overall width of frame of the GS .. would possibly make it quite tricky to work out a kickstart arrangement where you DIDNT smash your ankle to bloody junk on the way through!!
so... from my completely amateur perspective... but i do have a little 'bush mechanic' .. you might call it redneck engineering .. experience ... i'd say .. overall.... in the end waaaay cheaper to just save up for another GS motor.... but if you are truly keen and dedicated to do the transplant... then its possible... its just the HOW!! :D
extended edit & addendum: the weight of the GS frame/body/bits is also going to be significantly higher than a 250 2 stroker bike (about double for standard motors etc... but you are changing the motor so that changes the overall as well) .. so the extra 'pizzaz' of 2 stroke acceleration will be muted a little... and gears/rpm... most dirtbikes are 5 speed .. you can adjust your sprockets to suit your desired top speed... however the specs i am looking at for a 95 CR .. 8500 rpm max... whereas the GS has a indicated 11k rpm .. although a lot of the riders on here reason that little is gained from going much over the 8500 mark anyway - considering torque/rpm levels .. i can see torque figures for the 2stroke .. but a quickish check for GS doesnt show any .. i assume they are out there somewhere? ..
anyway .. max torque is delivered in the CR motor at 8000rpm .. i've ridden one at that and thru that till it just about strangled... and that little single cylinder sounds very very busy!! .. no big drama if you enjoy the sound though!! ;) .. so the sprocket size is going to have to suit the riding style/location pretty much .. AND (yes it just keeps on going!!) .. i think i said in a previous post .. most of the 250 2 strokes .. 'almost NEED' to be 'thrashed' .. or at least given their head throttle wise .. otherwise they do tend to oil up plugs and get all gunky and grumpy overall.. they need more frequent oil changes and minor maintenance too...
i'll probably think of other things later...
all this being said ... i am still not an expert... complete amateur really... so i say what i see from the amateur viewpoint... not a mechanics/engineers experience... and while you are doing mech eng .. i see this as a start from a amateur experience level (no offense intended) .. as you have not done an engine swap in a bike before?.. and neither have i !! .. i'm not trying to talk you out of it... just stating issues that i see as probably having an impact on the project!! .. :thumb: :thumb:
Greattt!! Thank you janx, soo informative!!
I dont think i mentioned it before, but i wanted to make this a streetfighter. Not just rip the fairings off either, i want to make a different subframe and everything.
Im sort of leaning towards piecing together a gs motor instead, i just hateee paying for shipping haha.
But i had my cr125 motor out and in the gs for a little while, and it really looks do-able and fairly straigt forward. BUTTT it is a newer gen CR so the exhaust comes around the right side......which i do not have the GS right side removable frame piece which hindered my ability to judge how the exhaust fitment would be. But the shape of the frame is the reason i got the idea in the first place!! haha. And most likely if i do stick with the MX motor, it will be kickstart only, probably for ease of wiring (which i kind of just realized it probably would just be easier to wire an ignition instead of fabbing a usable kicker)
But that is still with a 125, NOT a 250! Ughh its buggin me out, nobody i know rides 2t anymore, only 250f or 450's!!!
So it basically comes down to how much i want to spend (which is not a lot haha) so ill keep my eye out for Gs500 motors and 250 motors and whatever comes first ill buy.
As for the airbox, id probably just go with a pod filter and adjust as needed. Thatd keep it simple an would give me more room for the battery box (which i have no idea where/how to mount yet).
ANYBODY work with Baltimore Cycle Salvage??? Heard mixed reviews and dont wanna pay $600 for a rusted out piece of junk.