185 bottom and XR200 top?

[ATC185R]

I need a topend in my 185 and was am thinking about making an auto x and have heard the XR has the most potential. Can I simply bore my jug out, slap in an XR piston, put an XR head and carb on it and fire it up? Or should I use 200x parts? Please fill me up with info. I'm hungry!

[The Goat]

i really doubt your jug could simply be bored out to a 200....but I could be wrong on that. why don't you just try to find a whole top end? they shouldn't be too much on ebay these days.

[ATC185R]

I'll check on the jug, but I think the 185 and 200 are the same core. The only reason I would use my own jug is because I could get a fresh bore out of it and it would be like stock demensions. Wouldn't have to worry about buying something off ebay that has been bored and honed 5 times. That way I would know what I have and it could match any piston I wanted it to.

[SWIGIN]

yes you can bore a 185 to a 200....thats what oldskool83 did to his

[ATC185R]

Thnx swigin I thought that was correct. I might have to talk to oldskool. I forgot about that build.

[The Goat]

the walls are really that thick on the 185? damn. that's actually good to know. sorry for misleading you man.

[84honda200s]

i have a cyl. thats bored to 67mm. i forgot if its a 185 or 200. what ever it is though it is a bored cyl. the walls are thin but they claim you can bore a 185 3.5mm over and a 200 3mm over. i wouldnt do it though. it would be a time bomb waiting to blow.



wouldnt it be cheaper to just by a xr200 cyl. and use your head ? i mean you would have to pay to get it bored and then piston cost. if you were to buy a xr or even a 200x cyl. there would be no need to pay to have it bored all you would need to buy is a piston. even then i have a oem piston and rings (used) for a 85 200x. you can have it 10 bux shipped. hell i may even have a spare 200 cyl. im pretty sure i do. i have like 3 cyl. laying around.

[oldskool83]

yeah xr stuff matches up...stock xr200 bore is 65.50mm. i would just use what you have, xr stuff is not as plentyfull as 185/200 motors or parts yet on ebay.

[ATC185R]

Ya I'm finding out that a lot of the XR200's built in the 80s are still running. No parts on ebay. Maybe I was mislead. Doesn't the XR have a hotter cam and a higher comp piston? Is the power curve that much different than a 200x. How does the 200s fit in power wise? Is it left way behind by the sport engines?

[84honda200s]

the only thing that hurts the 200s engine is its tranny, compression and cam. i put a 200x cam and 10.25:1 wisco piston and rings in and it made a world of difference. im still using the tranny but the motor part of it has bin modded as much as a possibly can.


if i were you id get a 200x or 200s cylinder put a xr cam in the head and get your self a 10.25:1 or so piston and rings. you will be set. ive done it a few times ( i used a 200x cam in the 200s top end) and it works pretty good. ive built 2 of them and going on my 3rd. they arnt hard to build and are kinda under estimated in my opinion.

about the only thing that is different between a 200x cyl and a 200s cyl is the cooling fins. the fins on a x cyl are deeper and shaped a little different.


what ever you decide i wish ya good luck. if ya need any parts let me know. ill see what i got.

[SWIGIN]

the only thing that hurts the 200s engine is its tranny, compression and cam. i put a 200x cam and 10.25:1 wisco piston and rings in and it made a world of difference. im still using the tranny but the motor part of it has bin modded as much as a possibly can.


if i were you id get a 200x or 200s cylinder put a xr cam in the head and get your self a 10.25:1 or so piston and rings. you will be set. ive done it a few times ( i used a 200x cam in the 200s top end) and it works pretty good. ive built 2 of them and going on my 3rd. they arnt hard to build and are kinda under estimated in my opinion.

about the only thing that is different between a 200x cyl and a 200s cyl is the cooling fins. the fins on a x cyl are deeper and shaped a little different.


what ever you decide i wish ya good luck. if ya need any parts let me know. ill see what i got.

the thing is, all that ends up being is a stock 200x with a 10.25 thats silver instead of being black and no kicker.

your idea of built and mine are 2 diferent things

the 200x cam is a hair larger then a 200s or 185 cam (i dont have specs)

and they say a xr200 cam is a hair larger then a 200x cam but do not spend a lot on a stock honda cam since you can get a new aftermarket cam for just over $100

p.s. a guy on here sold oldskool83 a old worn out 200x cam for $45 and it was junk.....i dont see the point of spending close to 1/2 the price of a new cam on a old stock cam

[84honda200s]

the thing is, all that ends up being is a stock 200x with a 10.25 thats silver instead of being black and no kicker.

your idea of built and mine are 2 diferent things

the 200x cam is a hair larger then a 200s or 185 cam (i dont have specs)

and they say a xr200 cam is a hair larger then a 200x cam but do not spend a lot on a stock honda cam since you can get a new aftermarket cam for just over $100

p.s. a guy on here sold oldskool83 a old worn out 200x cam for $45 and it was junk.....i dont see the point of spending close to 1/2 the price of a new cam on a old stock cam

i hear ya. but i got the 200x cam for 10 bux on e-gay a while back so i decided to roll with it. i can get a brand new xr200 cam for 60.00 and from what i hear ...they are about the same as a aftermarket cam. (thats just what ive bin told though) im thinking about buying one for the motor im building now. im taking my time on this one. its got a new crank, bearings, rod, clutch plates and spring. thats a ok start.


yes your "building" and mine are probably like day and night. but if your thinking im just putting a piston in a 200x cylinder and calling all good you have me all wrong. i put allot of time and work into my motor. it took me more than 2 days to port it out, then i had a flywheel lighten by ronnie a while back, 30mm carb, bassanie exhaust, and some other stuff.


if i somehow stepped on your or someone else's toes .....i didnt mean to. SWIGIN ive herd nothing but good things about your work from aaron. you sound like you know your crap allot more than i do. ive only bin in this game a little more than 2 years so im still learning. again man if you got the impression i was being a know it all i wasnt meaning to. i was just posting my experiences and what knew. im just thowing some options out there thats all.

[ATC185R]

Thanks guys this really helps! So right now I'm looking at locating a 200s cylinder, 10.25:1 wiseco, XR cam, 200x or XR carb (or bigger jets for my 185 carb), new clutch and pressure plates and stiffer clutch springs. THis should build me a strong 200x engine with an auto clutch hence the infamous "auto-x". QUESTION: Should I use my stock 185 cylinder and bore it out or find a 200 cylinder? also Are Barnett clutch kits over-rated? There is surely an equal alternative for less money. Should I just make heavy duty clutch springs and use OEM plates and discs?

[SWIGIN]

i hear ya. but i got the 200x cam for 10 bux on e-gay a while back so i decided to roll with it. i can get a brand new xr200 cam for 60.00 and from what i hear ...they are about the same as a aftermarket cam. (thats just what ive bin told though) im thinking about buying one for the motor im building now. im taking my time on this one. its got a new crank, bearings, rod, clutch plates and spring. thats a ok start.


yes your "building" and mine are probably like day and night. but if your thinking im just putting a piston in a 200x cylinder and calling all good you have me all wrong. i put allot of time and work into my motor. it took me more than 2 days to port it out, then i had a flywheel lighten by ronnie a while back, 30mm carb, bassanie exhaust, and some other stuff.


if i somehow stepped on your or someone else's toes .....i didnt mean to. SWIGIN ive herd nothing but good things about your work from aaron. you sound like you know your crap allot more than i do. ive only bin in this game a little more than 2 years so im still learning. again man if you got the impression i was being a know it all i wasnt meaning to. i was just posting my experiences and what knew. im just thowing some options out there thats all.

its cool man.....but to say a xr cam is the same as a aftermarket cam is funny since aftermarket cams go from mild to wild.

it might be close to a mild aftermarket cam

but yeah that was kinda me point.... if i had a 200x or xr cam thats good just laying around id throw it in too.....just dont pay alot for it

[SWIGIN]

Thanks guys this really helps! So right now I'm looking at locating a 200s cylinder, 10.25:1 wiseco, XR cam, 200x or XR carb (or bigger jets for my 185 carb), new clutch and pressure plates and stiffer clutch springs. THis should build me a strong 200x engine with an auto clutch hence the infamous "auto-x". QUESTION: Should I use my stock 185 cylinder and bore it out or find a 200 cylinder? also Are Barnett clutch kits over-rated? There is surely an equal alternative for less money. Should I just make heavy duty clutch springs and use OEM plates and discs?

the best clutch you can build IMO is stock fibers with barnett springs....the springs are cheap ( like $12)