86 200x motor rebuild help

[BigReds Forever]

I finally got a kicker for the 200x, and surprise, surprise, after sitting for a few years the motors tight. I looked in the cylinder and it doesn't look that bad, but I think Ill use this as an opportunity to do a top end job and general checkup. Plan is a 10.25 wisco piston/rings/.5mm overbore, clean up the valves, new seals and gaskets, clean the oil screen/rotor, and check out the clutch. I just wanna know if theirs anything else I should be looking for.

Also, from what Ive heard, an aftermarket cam in these motors isn't such a hot idea as far as reliability goes. Does anyone have any experience to share with me on this issue? I want this to just be a nice torquey reliable trail rig. I figure with the increased compression, 28mm carb, K&N, and supertrapp exhaust, it should preform pretty well and still be reliable.

Ive done a few rebuilds but I know this motor is a bit different than most (especially the top end) and I'm just looking for anything to look out for or any previous experience that anyone may have to share.

Thanks in advance.

[HaggLE]

Use a carb like this one on ebay
http://cgi.ebay.com.au/NEW-KEIHIN-RE...QQcmdZViewItem
Easy to tune and work on, might need a 115 or 120 main i think.
Definately put a new set of valves in it, they are what wear out first, the next thing is the conrod.
Oh and only overbore it if you have to (damaged bore - rust, scoring etc) the extra .5mm isnt going to give you any performance increase.

[Dirtcrasher]

Both NINJA and myself ar planning on building a couple of 86 "SCREAMIN DEMONS". He had one before that proved to be pretty reliable.

I am going with an agressive cam, 11:1, porting and race gas. I've already got the Curtis Sparks head with the cam and porting.

Hopefully NINJA will chime in.....

[SWIGIN]

i dont see a problem with going with a cam as long as you also use HD springs and hardened rockers

[super90]

Where does everyone get these high compression pistons and cams for the 86?? Ive looked everywhere and cant find anything!

[Bryan Raffa]

Where does everyone get these high compression pistons and cams for the 86?? Ive looked everywhere and cant find anything!

http://www.webcamshafts.com/pages/honda-atv.html

[super90]

Thanks for the link, never found that site before. Now where do you find a high comp. piston for the 86?

I think adding all these hi performance parts would take it toll on the engine quite fast. The 200x engine wasnt exactly made to "scream" like todays 4 strokes are

[SWIGIN]

www.wiseco.com


a little home work goes a long way

[BigReds Forever]

Use a carb like this one on ebay.
....Oh and only overbore it if you have to (damaged bore - rust, scoring etc) the extra .5mm isnt going to give you any performance increase.

Man I would love a carb like that, or an actual PWK, but well have to see how funding goes. right now I have a knockoff round slide 28mm.

The only reason I said .5mm is because thats the first overbore that wisceo makes and I figure I will have to bore if the piston is tight. Im planing on sticking with their 10.25 so I can still run the good 92 non-oxigenated pump gas that I can get in my home town.

As far as valves, I will probably replace them, but has anyone done guides on one of these? http://www.denniskirk.com/jsp/produc...d=&mmyId=11866 Will those work? or should I get the oem ones?
Ill also do some mild port/polish work which will basically amount to cleaning up any casting flash or sharp edges and smoothing our the rest. Ive done that before but dont feel competent enough to start grinding in there.

If I did go with a cam, Id probably go with web's mid range one. This thing has to keep some real bottom end torque. It says you will need their HD spings, but nothing about the rockers. In fact, Ive never seen anything for aftermarket rockers. Can anyone clue me in?

Also, just so everyone has an idea, the exhaust will be a moded 450r headpipe linked to a supertrapp.

Keep the great info coming guys!

[SWIGIN]

if the valves are not worn id keep running them


megacycle cams does the hardened rockers....with out this done the stock ones will ware out in a year or 2 (with HD springs)....and tear up the cam

i dont like web cams fot the simple fact they dont seem to offer hardened rockers....and megacycle cams have always impressed me

edit.... web does offer hardened rockers but compare the cam specs to megacycle