Big red 200 motor upgrades?

**MN250R** · 01-04-2019, 11:54 AM

Looking for some ideas to bump the performance a little on my 200. I know I won't be making power out of her like a 250 but was seeing if anyone has done anything to there's? I here an xr 200 cam??200x cam?? 200x carb?? I already did the 200m front end upgrade on mine.

Thanks!

**Gabriel** · 01-04-2019, 12:29 PM

Exhaust will help a lot. Not many options so you’ll have to find a used set up or start fabricating.
The exhaust is pretty small and restrictive.

Do a compression test. If it’s low, rebuild. The 200 doesn’t have overly thick cylinder walls so boring for displacement is a waste of time. Only bore to get a good piston fit.
If you’re inside a 10.5:1 compression piston will help a lot but I wouldn’t go higher.

If you’re handy enough, a little attention and love to the ports will help a lot. Don’t bother trying to get a real port and polish job, just clean things up and remove all the casting flash. It’s amazing how much casting flash some heads have in the exhaust port.
A good valve job after that.

PROPERLY jetted and tuned carburetor makes a world of difference. Can’t guide you there. I’m still in the infancy stages of learning that.

Also don’t forget the little things that may not do anything by themselves but compound together to make issues.
But a quality air filter. Don’t adjust the carb without it.
Clean the centrifugal oil filter.
Inspect the pulse rotor advance springs. PS2Fixer can sell you brand new ones. If they’re weak the advance will be off and performance will suffer.
Set the timing with a light and be sure the pulse rotor gap is in spec.

Good luck!!

**shortline10** · 01-04-2019, 12:34 PM

Motor needs to breathe more to make more power . The factory x and r cams are not noticeable upgrades but good as a factory replacement only IMO .

A minimum of a mid grind Web cam , high compression 10.25 wiseco piston , 26mm xr200 carburetor and a performance exhaust will wake that little motor up .

**MN250R** · 01-04-2019, 01:24 PM

Awesome! Thanks for all the advice. I will do a compression test on her and see where I'm at with that first, Then go from there about the other areas to check.
It runs good, but if I snap the throttle fast it bogs, especially in high gears. I'm assuming it's lean. It just cuts out. Air filter is new, everything cleaned and no air leaks around the cylinder and manifold. I also cleaned the carb. Its probably the cheap Ebay carb rebuild jets I got. Lol

**ps2fixer** · 01-04-2019, 02:59 PM

I haven't seen it done yet, but wouldn't a 200x cylinder/head be a direct swap to up the compression to 9.6:1 vs the 200ES having 7.8:1. Of course if you go with new piston etc I guess sticking with the stock cylinder etc would be best? Not super ontop of the 200ES/S/M head vs the 200X head flow wise etc, but stock to stock the 200x is the highest outputing of the 200 series that I'm aware of, atleast in the 3 wheeler models.

Based on the service manuals, the 200ES is 13hp while the 200X is 18hp.

**350for350** · 01-04-2019, 10:00 PM

The difference is mostly in the higher compression and bigger cam on the 200X.

**Gabriel** · 01-05-2019, 08:45 AM

Cooling fins are bigger too.

**MN250R** · 01-05-2019, 10:53 AM

Would something like these work?

https://rover.ebay.com/rover/0/0/0?m...2F381903701199

https://rover.ebay.com/rover/0/0/0?m...2F332776359979

10.25 compression? Or is that to much? The stock compression is 7.8?

That piston is for a 200. Would that be the best piston to go with? Or a 200x / xr 200? Thanks!

**350for350** · 01-05-2019, 10:35 PM

Originally Posted by Gabriel

Cooling fins are bigger too.

I was only talking about the difference in power. Of course you're right about the cooling fins.

**350for350** · 01-05-2019, 10:42 PM

Originally Posted by MN250R

Would something like these work?

https://rover.ebay.com/rover/0/0/0?m...2F381903701199

https://rover.ebay.com/rover/0/0/0?m...2F332776359979

10.25 compression? Or is that to much? The stock compression is 7.8?

That piston is for a 200. Would that be the best piston to go with? Or a 200x / xr 200? Thanks!

Either of those two listed pistons should work. A 200 top end is basically a 200 top end. The 200X just has a higher stock compression ratio than the other 200's do. I'm not up as much on the XR200, but I think it's the same. Now the differences would come with the 86/87 200X style of engines. They are completely different. As for the XR, as long as it's a two valve engine, I think it should be the same (I'm not sure if the XR200 ever went to four valve or not).

**ps2fixer** · 01-05-2019, 10:57 PM

Yes the XR200 had a 4 valve version, it was similar in design as the 350x head, I can't remember if each valve port for exhaust was separated or not, but it runs dual carbs. Might have been a 250cc XR engine, can't recall for sure, but I have one. It's a "progressive" dual carb setup, a primary, and after around 1/2 throttle the secondary starts opening, kind of like a 4 barrel carb on old car engines.

EDIT: Yea, the dual carb setup was the XR230 & XR250R according to wiki. It also says the XR200R engine was modeled after the XR250R engine (RFVC engine) in 84-85, I suspect those years the parts might not interchange over since they are similar/based on the 4 valve engine.

Source: https://en.wikipedia.org/wiki/Honda_XR_series#XR_200R

**MN250R** · 01-07-2019, 03:08 PM

Thanks for all the replies. I'm thinking I might go with the 10.25.1 piston. I'm sure its quite bit more noticeable over the 9.5 one. Does anyone know if the xr200 cam is a low end torque cam? Or should I just keep the factory one I have if its within specs.

**MN250R** · 01-11-2019, 09:18 PM

Originally Posted by Gabriel

Exhaust will help a lot. Not many options so you’ll have to find a used set up or start fabricating.
The exhaust is pretty small and restrictive.

Do a compression test. If it’s low, rebuild. The 200 doesn’t have overly thick cylinder walls so boring for displacement is a waste of time. Only bore to get a good piston fit.
If you’re inside a 10.5:1 compression piston will help a lot but I wouldn’t go higher.

If you’re handy enough, a little attention and love to the ports will help a lot. Don’t bother trying to get a real port and polish job, just clean things up and remove all the casting flash. It’s amazing how much casting flash some heads have in the exhaust port.
A good valve job after that.

PROPERLY jetted and tuned carburetor makes a world of difference. Can’t guide you there. I’m still in the infancy stages of learning that.

Also don’t forget the little things that may not do anything by themselves but compound together to make issues.
But a quality air filter. Don’t adjust the carb without it.
Clean the centrifugal oil filter.
Inspect the pulse rotor advance springs. PS2Fixer can sell you brand new ones. If they’re weak the advance will be off and performance will suffer.
Set the timing with a light and be sure the pulse rotor gap is in spec.

Good luck!!

Thanks for the advice. Wll i tested the compression tonight and had about 100 psi. It still runs fine and starts easy which is kind of wierd if the compression is that low. I know it lacks in the power department unless your in low range. I will do a little porting as you mentioned to clean up the ports some. And upgrade the carb and do some plug chops for jetting.

**Gabriel** · 01-11-2019, 09:51 PM

That’s not uncommon at all to run at that pressure.
I had one running at 70psi before I overhauled it.

**ps2fixer** · 01-11-2019, 10:16 PM

Yea 100psi is low, but not so low it won't run. I tried to find a spec, but I guess biggs engines don't have a PSI rating because it requires special equipment, so they say flywheel kick back is their compression test. Anyway here's a random thread of a guy at 60psi with a running engine and it seems like all the replies are like ignore the compression it's normal. Those briggs engines are only like 6.5:1 compression ratio lol.

https://www.smokstak.com/forum/showthread.php?t=151221

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Big red 200 motor upgrades?