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View Full Version : '83 ATC 200 rebuild.



Gabriel
07-13-2018, 10:12 AM
I have never rebuilt anything like this before. Briggs & Strattons galore. Several chain saws and a small block chevy or three but never a Honda. Fingers crossed I don't screw this up.


The engine ran but smoked like a freight train. Compression test showed 50 PSI. A spoon of oil in the cylinder jumped the compression test to 125 so rings bad, valves good. I got it down and most everything looks great. Cam mic's within spec. No galling or scoring on anything. Looks like rings and gasket set will get the rotating assembly back in order.

Two bumps in the road so far.

First is no biggie. The head is made for a cable actuated compression relief. The pull rope cover is not. I have the parts from a donor motor i was given to put a manually operated lever in it's place. I'm reasonably certain that'll work but would like a second opinion. Chances are, I'll never use it anyway, I just don't want the lever flopping around with no cable.

Second is a big deal. The pulse rotor assembly is screwed. I do NOT know how it ran. A testament to how well designed the motor is. The springs are in pieces. I found the chewed up remains. The rotor is mangled. The advance weights are bent beyond use. The donor motor isn't much better.
Does anyone have a rotor and the spring weighted advance assembly they would sell. I have several modules and all the housing parts, I just need a usable rotor and the advance assembly. I COULD use just the weights and springs but would just as soon buy the whole contraption if someone has it.

Thanks for the help. My parts should be in Tuesday and I'll start getting it back together.

125Mmadness
07-13-2018, 10:43 AM
I've got one you can have if you pay shipping and a rocker cover for manual comp. release I'd take $15 for it. Welcome to the site.

Gabriel
07-13-2018, 11:26 AM
Sweet! PM sent.

Gabriel
07-13-2018, 02:36 PM
Ok, I just got the rear brakes replaced and adjusted.
Decision time. I'm missing pretty much everything for the front brake assembly. Do I start tracking it down and put it back or just run it? I'm too old for wild riding so I bet just the back would be good enough. Either way, back burner project.


Poor old gal. At least she's where someone will try to care for her and enjoy her.

253549


Waiting on parts.............

253550

shortline10
07-13-2018, 03:50 PM
Make sure to hone the cylinder and check it for roundness , don’t want to see you have to do it twice :)

Gabriel
07-13-2018, 05:11 PM
Well, I don't know what kind of Frankenstein set up I have managed to cobble together here, BUT.....I have brakes.

I pieced this together from the mountain of spare parts I got with the bike. I had to machine a spacer to make it work but I had a set of brand new pads in my boxes of parts that fit.
All I need is a cable and lever to make it work. That's not a big deal.
BUT...Here's the rub. It carried a different bolt pattern than my front wheel. I have several spares but I have nothing with this pattern. It measures out to a little over 5 inches so I am guess it's a 130mmx4 pattern? Does that sound right?

Anyone have a 9 inch front wheel with that pattern they wanna sell? LOL!
Looks like a 125M or a 185S wheel might work. Anyone know for sure before i spend money?



253551

Gabriel
07-16-2018, 11:11 AM
The more i root around in this thing AND read the manual, it's readily apparent this is NOTHING like original. The ATC200 had a rigid fork system. This one does not so someone has changed the front end out at some point. No crime there but that explains why I don't have the parts to make the front wheel and brakes all jive together. Not a huge deal. I found an 8" wheel on Amazon for less than $40.

I took it as close to bare frame as I intend to over the weekend and there's been some mods (poorly) done. Pretty lousy welding done to some pretty lousy exhaust hangers. I re-welded them to suit me and spent some time grinding them smooth and smearing a little paint on them. There's not a properly routed anything. No tie straps. I don't really know the PROPER route for the cables and such so I'll just have to get the engine running and then route them the best I can to be out of the way and not bind. I hate zip ties as opposed to the proper aluminum straps but that looks like where I'm headed.

atc300r
07-16-2018, 12:20 PM
The 83 atc 200 has a factory front suspension. 82 atc 200 and older came with solid forks.

Gabriel
07-17-2018, 10:02 PM
Ok, change of plans for this. I was just given an 86 200S. Perfect frame, no mods or damage. The rear plastic not not cracked or or broke but BADLY sun faded. The seat is great, just needs a new cover. The motor is mostly gone.
There's SO much shoddy work done on the ATC200 that I have been trying to fix, I think I will give up and shift gears now. I plan to strip this 200S to bare frame, paint and slowly reassemble RIGHT.
I found some hidden welds this morning on the triple tree that scared the snot outta me.

I think despite the extra work, I will have a better, more reliable ride for the effort.

Gabriel
07-19-2018, 11:11 AM
Got the frame sandblasted yesterday and primed with etching primer. Got up this morning and used Rustoleum Professional grade spray bedliner to paint the whole thing black. Should be a good tough finish.
I'll let it dry for 48 hrs and then grind my grounds and tap all the holes clean. Then start pulling all the good off the bad frame.

This will still be a mix match but at least it'll be 'right' and something I understand....More importantly, something safe that I can trust.

I really tried to fix the ATC200 frame but there's been some work done on the steering that I simply DO NOT trust. Fortuitous to find this 200S. There's a few things I really like better. The bigger central mounted muffler for one. I'm going to tear it down, clean and repair anything inside. Give it a shot of BBQ grill paint and use that one.
This will also let me take my time and replace all the wheel bearings, need it or not.

Question? What are you guys thoughts on the enclosed chain guard? I hate it. It's a nuisance. I am considering deleting it. Billions of miles have been ridden on machines with open chains. Any detriment to my NOT putting this back on?

Thanks guys! I'll get some pics once its dry and I can move it into better light.

125Mmadness
07-19-2018, 05:11 PM
I'm sure everyone will disagree with me, but I see no reason to keep the gaurd. I took it off my 200s because it was very bent and I never had an issue and I did a LOT of trail riding. My 250x did not come with one from the factory and I've never had an issue with it either.

djm0242
07-19-2018, 05:54 PM
I like the chain guard. I’ve had with and without. I just think chains last longer and stay lubed longer. Good luck on your build btw.

Gabriel
07-23-2018, 04:55 PM
Waiting on my chain/sprocket set to get it back together.
I'm hoping I can tune it up and smooth it out. Motor sounds strong but has a nasty flat spot in the carb. It's a brand new Ebay carb. Starts up and idles great. Hit the gas, wuuuhhhh. I moved the needle to the second to last position and it does a little better but I will have to wait to get it off the jack stands to really get into it.

Found a great solution to the rear mud flaps! A 12" wide Hoosier drag slick. No pesky steel belts and plenty wide. Cut the side wall out and then make one cut to un roll the tire into a long strip. The natural curvature of the rubber makes them sit on the fender without bucking up. Need to do a little shaping and attach them & I'll get a picture up.

Getting closer!

Gabriel
08-04-2018, 08:58 PM
Got everything done but the seat cover. It should be here next week. It's a mix matched fugly thing but it runs like a champ! Starts first or second pull pretty much every time. Only when I run the carb dry (I have a big habit of doing that before putting stuff away) does it take 4 or 5 pulls. I'm ecstatic. Wadded up a beach towel and took it for a spin. Plenty of power (for me). New brakes. Nearly new tires. All new wheel bearings front and rear. Fresh top end. A little care and this should be going for years to come.

I'll get a pic up next week when I get the seat finished.