Gas Gas 200 teardown

[sweeper]

Had this 99 ec 200 sittin on a stand in the shop for a couple years now.She was pretty clapped out and the engine was locked up.I was trying to make my life easy and buy another complete bike before opening before opening what I knew was gonna be pandoras box.After a year of browsing craigslist and running wanted ads the extra parts bike couldn't be had.So last night I decided it was tup ime to open her up.Couple things I noticed right off the bat when I took her off the stand and rolled her over to our gearshef to work on was what a tank this thing was.Im gettin older too but I'm not kidding Id hate yo have to push this thing outta the woods.Its my first Gasser tear down,one thing I noticed right off the bat was the bike really doesn't come apart that easy.I can tear my old 87 cr 250 down and have the engine out and sitting on the bench in about 15 minutes.Not the Gasser.Once I got all the plastics off,the subframe and pipe which took awhile,I went after the engine.The shifter is a pain.I went after the barrel and ran into another huge pain in the ass.Broke the bolt that holds the water pump actuater arm on the power valve.Snap.Cheesy easy fix to beef it up.The huge obstacle was the barrel nut in that corner was put on how?Ground started gr!inding down on one of my old favorite half inch wrenches until ultimately there was nothing left.Never got a wrench on it and went after it with a center punch.That worked,no clue yet how a new nut is goin back on yet.Slid the barrel off,its a tight fit but with the piston all the way down I got her.Barrel looked great,piston looked almost new lots of rust stain on the rod.Water had gotten in tbrough a crack in the carb connection and that that.Next step engine removal.Another huge pain.Swing arm bolt was a little stubborn I expected that.Got that out eventually and removed the other engine mounting bolts.Next F**kshow,the engine is a monster and is built with no room to spare.It literally is formed around the front mount and the swing arm.So can't tilt it up and out or lift it from the back and out.Just halfway out wedged and stuck sliding off the stand time of my life.Regrouped after my wtf now moment and pulled the upper shock bolt to get the upper shock out of the frame and get some play in the swing arm.Used a pry bar and worked it out.The engine is heavy,ridiculously heavy.Which I like.I woulda thrown this bike in the dumpster hours before if I hadn't been so impressed with how beefy the engine was built.Got the thing on the bench crank and rod frozen solid.Dumped the engine upside down in a bucket and even after 2 yrar in the shop gunk and water poured out.Heated a quart of marvel mystery oil up nice and hit almost boiling dumped her in there and let her sit awhile.After about half an hour dumped a can of coca cola in on top and went to work on her and got her freed up.But of course not good news.So where from here.The bike has some real funky features like the tack welded wire carriers and the like.But this engine is impressively built so I'm gonna see it through.

[sweeper]

1. What are the crank rebuild options.
2.Am I the only guy to snap the power valve actuater nut off.Ill be modifying this myself,too cheesy not my style.I was impressed with the simplicity of the powervalve and linkage,especially the wire arm,smart.All attached with the worlds smalles bolt.
3.What special tool is required to tighten this barrel nut that is tucked under the powervalve.
4.Where can I get a factory service manual for this baby before I split the cases?Splitting cases is something I can usually do in my sleep.But after several traps,half thoughts and no thought engineeriing Ill wait.

Any thoughts,criticisms hindsight revelations would be greatly appreciated.

[noobi]

Ha
You aren't the first person to snap that retaining bolt, and you wont be the last.

The rod, I think, is the same as the 250/300s, which is the same as a CR250. Someone with an older motor will have to confirm that though.

You just need a very skinny 13mm ring spanner for the PV side nut.

Can't help with a service manual that old though, there is one for an 05 250/300 motor floating around somewhere though. The engines are evolutionary instead of revolutionary, so the newer manual probably applies to the older motors somewhat.

The 99 would have the counter balancer cut out, but not the balancer itself?

[sweeper]

Ill take your word for it on the wrench.But I ground that baby down to nothin and still never got on it.Thought about hoggin out some of the barrel behind it,but haven't looked the barrel over close enough yet.I have some new con rod kits for Honda 250s still from back in the day, would be sweet if I could use one.Might even have a new old hot rod floaten around.
I don't know where the counterbalancer used to be but there is a casting void on the ignition case half that looks about right for it.Ha this engine with a coubterbalancer add another 10 pounds.What a monster.

[noobi]

Maybe use a slimmer nut. Its not that big of a deal on the newer cylinders, so they must have improved the clearance. So opening it up a bit is probably viable.

So yea, no counter balancer.

Is there any serial number on the con rod?

[Rick]

Ha!!!! Built like a Sherman tank! Badass motors! That's why there are so many older GG bikes still around! Resale sucks.....so just ride it!

I have a complete service manual...........

[sweeper]

Yeah their was something written on the rod,but I didn't catch it..I slapped the barrel and head back on so I could use the kickstarter to keep turnin the motor over once I got it freed up.


Rick ,you have a service manual for a 99-2000 ec 200?One you would sell?Not sure if its an ec actually now that I'm learning some things about them.Mostly that I got a lot to learn about them.I'm a TM guy and they are more straight forward as far as options and models go.

Yeah I'm not interested in selling it at all.Id rather dump $1200 and a crapload of time into it and still end up with a semi clapped out beater,then buy a near mint one for $2000 that I can ride today.

[sweeper]

As far as this 200 goes I've heard enough of you rave about these things so I'm goin for it.I've also been on a forum where the entire forum thought that a kdx 200 was a race bike more then a trail bike.Not one member on that forum agreed that the bike is a damn good trail bike as opposed to a legendary racing machine which has won numerous AMA national championships and FIM world championships and a multi time Six Days overall winner.I'm not even kidding,the whole forum,wasn't a kdx 200 forum either.So to make a long story short.I hope you guys are right.

[funmachines]

I just did a new piston, crank bearings, a few other bearings and the key seals on a 99 200 for my son. It's not too bad - hopefully you'll be happy once you ride it.

The one thing I changed was the axial clearance of the cranks bearings - I added a couple of shims from McMaster Carr to drop the clearance a bit. The rest was pretty easy.


Good luck with it.

[sweeper]

Originally Posted by funmachines

I just did a new piston, crank bearings, a few other bearings and the key seals on a 99 200 for my son. It's not too bad - hopefully you'll be happy once you ride it.

The one thing I changed was the axial clerance of the cranks bearings - I added a couple of shims from McMaster Carr to drop the clearance a bit. The rest was pretty easy.


Good luck with it.

ugh,you make that sound so easy.I rev the crap out of these small bores,how bad are these crank issuse?Is it everyone of them or a here and there thing.