PlanetMinis Forums banner

klx 125 build

7676 Views 29 Replies 6 Participants Last post by  huntmod
well its on ,pulled engine and split cases tonight also picked up an old 230 cyl,head and cover (withcomp release). head is basically the same with seats cut for 28/ 32 valves instead of 26/30. ports appear to be close. cylinder is roughly around 5.5mm taller and cover has built in mech compression release lever ( cable operated I suppose).Old engines use stud and klx uses bolts on cyl and head. there are about 6 or so engines that share similarities with the klx 125, so possibilities are plenty.main bearings are the same up to the 230 and poss even some of the 250s. I found a guy who has alot of this old stuff and was diggin and comparing all night(except for dr 200). rod has plenty of clerance inside lower end for plenty of additional stroke,crank throws are the only concern with only about .080'' clearance to 5th gear and about .200'' to 4th. plans were to look into a dr 200 crank yielding about 10mm more stroke and larger wrist pin, but dont know if the throws are larger and if so by how much. stock 125 throws are 4.325'' if anyone knows throw diameters on a 200,230 or whatever else may fit in to these cases or have any other ideas I would appreciate the help. plans are to build something at least 250cc with lots of head work,custom exhaust,cam,carb and whatever it takes to make it an all out performer. my son plans to ride it with the 250 class just to be different and have a father son project as well.
1 - 20 of 30 Posts
is the 230 head "bathtub" combustion chamber like the klx125?
no it is more of an open chamber, I will be ccing it in the near future as well as the 125 head to see how much diff there is but it is very obvious.
you can use the 230head we have been using it sense 2005,you will loose some compression with the franks piston because of the chamber.we have our own pistons for the 230head at 14.1 compression and 198cc.also you can use the 200 crank if you turn it down hits gears.also you cant use the 230 crank because of oiling system
thanks good info. is this 198 piston something you had custom built or is it available to others. also are you using the stock stroke. thanks
For a lazier guy, how much difference is there in motor mounts between 125 and 200?
200 is a tad taller, you have to do some fab work.
we had them built and we are running stock stroke,if any one is interested in the pistons let me know.there is a bit of work to get this set up to work because the cases have to be opened up and we have a different sleeve.also we have a dr200 motor in one of our frames and all you have to do is oblong the upper mount holes.
if the cases are the same on the 200 as the 125, and the 200 cylinder is the same height as lt 230 ,which is about 5.5mm taller than the 125 cyl. then installing a whole 200 eng prob wouldnt require anything other than a little work on the upper engine mount as norcal mentioned. the only problem is locating a dr 200 engine. I have found a sp 200 but dont want the 6 speed for dirt. I prob will mod the throws on a 200 crank but would like to know for sure if it will use the same stator,flywheel,and primary gear. also what is rod length on 200 anybody?
with the cylinder being taller installing the carb is bonna be a problem, you not gonna get the huge tm28 pumper i there for sure.
I know, I know, that this is a long post butt, I've been trying to follow along with you DRZ/KLX 125 motor heads for some time now.. (reading all of your builds) I have an disfunction called C.R.S. (Can't Remember $hit) Help me try to get this right.

So? All the descendents from the 125 engine are as follows, pretty much every small vertical single cyclinder 4T engine Suzuki has produced. DR 100/200, SP 125,200, ATC LT 125,185,200,230 pull starts with auto clutch and the 230 Quad sport. Did I miss any? Wasn't there a 250?

All the kick start models (except the atc LT) will interchange most-to all crank case parts except the 200 and 230 quad sport because of the crank interference, primary gear drive, ingition, and oiling systems? They also have a longer stroke, longer rods, larger wrist pin size, and tall deck height to match.

So, All models will interchange top ends (cyclinders and heads). Even with the exemption of the crankshaft stroke and matching componets above for the 200+ models. For example and NOT FEASIBLE by any means but, the 230 qs head will bolt on a DR 100 engine? How, Does the LT 185 atc come it play

Other than the top ends the atc/LT crank case parts are renderd usless becuse of the auto clutch and pull start, etc.

OK. All performance camshafts (web, megacycle) can be installed on any of the cylinder heads mentioned above. The decompression heads (pull start models and the kicker qs) were not camshaft operated, It was mechanical.

Besides the limiting wrist pin size, A custom + 70 mm piston and +74mm o.d. sleve, w/stock stroke and cyclinder is possable such as your's Norcalklx.

Ive read blips of a Honda rod swap for larger wrist pin size and piston, but no detials.

I'll stop rattling and lock up the brakes right there. I could keep go'n.

Do I kinda, got it straight?

See less See more
still trying to find out if a klx 125 flywheel and primary gear will fit the dr 200 crank. if so which year models. were the old (86) dr 200's off road only or were they dual purpose like the current models?
you dont want to run the klx125 ignition, flywheel weights 3.5 lbs and the ignition is horrible.
yeah I probably will end up running something else as far as ignition goes later on but was going to start with stock ign. was going to buy new 200 crank (for the additional stroke)but wanted to verify interchangability on the flywheel and primary gear before purchasing.may be better off stroking stock crank. dont know yet havnt had any 200 stuff to look at and compare. have been following hacks build and hope ours turns out as nice. thanks everyone for info can use all I can get.
just mod up the stock crank for the added stroke, while your at it lighten the hell out of it, the crank webs are huge, looks like a lt230 crank with a smaller rod. make sure you go with the #213 grind from webcams or even the other one with more duration. the pvl ignition makes a huge difference for sure. i just wish i could find a lt185 cover so this bitc$ is easier to kickstart.
I know aguy who has alot of the old atv parts.i picked up a head and cover with comp release but thought that it wa off a 230. will begoing by there again over the next couple weeks. not certain but I think I saw another cover with comp release. was going to save the stock crank is the reason I was asking about the 200 crank. thanks
sweet let me know how much for the cover. i need it bad, allready broke 3 sets of kicker gears this year.
damnit, i just missed one (lt185 valve cover)on ebay for $40, was on the damn phone please try and find me a valve cover with decomp mech.
pvl will fit on the 200 crank but the primary is different you might be able to use the 200 primary and clutch basket but not sure.I know that the primary ratios are different.
smrmx14 said:
pvl will fit on the 200 crank but the primary is different you might be able to use the 200 primary and clutch basket but not sure.I know that the primary ratios are different.

so if the pvl will fit I guess that means the 125 flywheel will? is the primary fit on the crank diff or is it the ratio diff or both. thanks.
1 - 20 of 30 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.