Hot, Reliable 200s Engine?

[Thunder]

So I just finished my auto X. And still have a 200x frame left over and a bunch of motor bits that came with it. I have an 83 xr200r with a stripped out kicker. A 200x case with a cracked rod and a POS 200s with a split case. So, what I'd like to do is...
Find a decent 200s complete motor. Put the cam from the xr200 in there. Use a 10:1 compression piston.
I have the carb from the 83xr that I'd like to try using. Put in new clutches. New valves and a valve job. Throw on a nice filter and exhaust and goto town.
What you all think about that?
I know it may just be a waste of time building a 200s but I'm a rookie. I like the auto clutch and it's perfect for the trails we ride up in the mountains and the muskeg we find below.
I just want to go fast.

[flynfish]

Then I would build it. We all were rookies too at one point. Do.it to it bro.

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[ironchop]

Nothing wrong with that idea. The Honda 200 motor benefits TREMENDOUSLY from a pipe, cam change, compression ratio boost, and modify the air box cover. Keep the 200S valve cover for the decompression lever assembly especially using a higher compression piston and being pull start.

I'm not sure if auto clutches can handle too much HP but I do know from experience with X motors which I think are identical top end as the S model (with the exception the X has a hotter cam and the S has a decomp lever)

You will be seriously surprised how much those mods and a good cam wake up that motor.

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[Scootertrash]

I have an 84 200S with a 10.25:1 piston. XR200 cam and carb, Supertrapp exhaust, unmodded airbox. I cleaned up, blended, and port matched the intake port and manifold, cleaned up and polished the exhaust port. The two guys I know that ride a 185 and another 200 both tell me they feel like they need another gear to keep up. It's a spunky little set-up and I like it. Being a hard tail it has it's limitations tho ;). I have plans to do a similar build in an AutoX

Back when I was researching this build there was a guy who seemed to know his sh!t about the Honda 200 motors and the XR200 cam was the one to go with as well as the XR200 carb, 82/83 if I remember correctly, in84 they went to a dual carb set-up for 2 years. With the XR200 carb you'll want the intake manifold too. I'll see if I can dig up the threads, I believe one or two of the AutoX threads I have were from the now defunct 3Wheeler.org, but might still be available.

This spring I'm going to find the modded airbox lid I have for this and throw it on and see what difference it makes. I never reinstalled it after the build because we were doing a lot of deep water puddle jumping, like up to the bottom of the fuel tank, and I didn't want to be sucking mudwater. ;)

I'll try to hunt up those threads in the morning.

[Thunder]

Awesome. Thanks for the positive input guys. I tossed around the idea of doing a cr125 or crf230 swap. It even crossed my mind to convert a 300ex into a trike. I don't want to have to buy a whole bike just for the engine and harness and seems wasteful to chop a quad up. So this makes the most sense to me.
I'm going to go all out on this one. Powder coat new plastics pretty much the works. Hopefully by this time next year she'll be all wrapped up!

[Scootertrash]

Here's a link to my build thread here:

http://www.3wheelerworld.com/showthread.php/140489-Scootertrash-s-85-200S-build?highlight=build

Still searching for the other info

[Scootertrash]

Here's a link to the .org Honda 185/200 cam info:

http://www.3wheeler.org/xf/index.php?threads/xr-200-cam.11756/#post-126369


Make sure to get a new cam bearing and washer for new cam!
There have been alot of questions surrounding the camshafts used on these models lately.
I thought going over all 3 variants of these OEM camshafts in one post would be helpful to many and answer some of those questions.

Camshaft Part# 14101-965-000
Status: Still available from your Honda dealer as of 12/09/04
This camshaft is used in ALL of the ATC 185/200 series engines except for the '86-'87 200X engine.
And yes, the '83-'85 200X cam IS the same as all the other ATC 200 models.
1980 ATC185
1981-1983 ATC185S
1981-1983 ATC200
1982-1983 ATC200E
1984 ATC200ES
1984-1986 ATC200S
1984-1985 ATC200M
1983-1985 ATC200X
1984 TRX200

Camshaft Part# 14101-446-000
Status: Still available from your Honda dealer as of 12/09/04
This camshaft is used in ALL XR versions of the 185 and 200 dirtbikes up to the 2002 model year except the '84-'85XR200R.
1979 XR 185
1980-1984 XR 200
1981-1983 & 1985-2002 XR 200R


Camshaft Part# 14101-437-000
Status: Discontinued at one point but currently available in limited Qty as of 12/04
This camshaft is used exclusively in the dual sport bikes and has a higher lift and duration than the XR version camshafts.
1979-1984 XL 125S
1979-1983 XL 185S
1983-1984 XL 200R

I also read that the stock 200X cam is actually bigger than the bike cams but the bike cams are better for low and mid-range power.


And


The measured height of the XL bike cam IS lower than the ATC cams. The lift isn't that far off from the ATC version, but the lobe on the XL185S cams ramp is longer......thus more duration.

The XR cams are close to mild web cams but take a little bottom end away.

Neither Honda cams require heavy duty valve springs.


XR cam for mid-range to top end.

XL cam low to mid-range.