I heard that the XR200/XR200R engines are the same as the 200X. If this is true does an XR200R camshaft in an 200X provide any more horse power when used with a 27mm carb. and an aftermarket pipe VS a 200X cam, 27mm carb. and an aftermarket pipe?

 

yes

 

lol

 

i'm not positive on the engines bolting up perfectly
but i know the pistons and sleeves are the same
one problem the cam chain are on different sides

 

Camchains are on the same side. You may be confusing this with the old mid eighties RFVC version of the XR200. It is built like a 400EX engine.

And the stock cylinder bore and piston size of the XR is different from the 200X and any of the other trike engines.
Doesnt matter if you are boring up though. Aftermarket pistons will swap.

Engines will swap, but you have to deal with a rearward kickstarter and you have to use the 200X intake....or since you going to a bigger carb, you will run an XR intake with a custom made airboot. Jeff (haywoodjalikme) on here did this just a year or two ago. He might have some pics handy of his intake and carb conversion.

XR cams are more aggressive than the 200X cam....which is more agressive than the 185/200 cam. But the most agressive cam is from the early XL200 dual purpose engines. When buying one new, you end up with an XR cam because Honda has now superceded many parts rather than continuing to make direct replacements. However, if you find one used, and can get the rockers and cam bushing from the same engine, it is a very good cam and has almost identical performance characteristics as the aftermarket cams from Web and Powroll.

I have used several 26 carbs over the years, but only a couple 27s. They seem to suck up too much bottom end generally. These engines have a fine line between just right and too much when it comes to the carb. I dont know what else you have done, but if a cam is your only internal mod, I believe I would skip on the 27 and go with a 26.

An old friend of mine is running a 27 on his 236 stroker converted to run straight alcohol. It is a very awesome ride. However, he is only a weekend trail rider who hardly ever gets out of 3rd gear....and thats generally just to get to where we plan to ride at!! LOL
Good luck on your project.