Header options on ATC 200/200x pre '86

[YTZ drew]

Will be using the block off plate in a different application.

If I was a betting man, I'd bet you're blocking off a cam chain tensioner hole in a 230 cylinder...

[Dave8338]

If I was a betting man, I'd bet you're blocking off a cam chain tensioner hole in a 230 cylinder...

Are you planning a trip to Atlantic City, any time soon ?

[Dave8338]

Someone has been sleeping in MY bed...



AND:






Now it gets interesting...

[Dave8338]

So... after tearing into the little beast last night, it is obvious that someone has been there before me. Not surprised on a 30+ year old machine. Expected, actually. What I didn't expect to find were the spring tops. I haven't put the compressor to them yet but they sure appear to be titanium. Couldn't even make a mark with the hardness file.
Will have to gauge the springs too. Valve guides are shiny silver and not the bronze that I expected.

Also, the piston is obviously domed and fly cut. Has HON DA written just like that, with the wrist pin in the middle. It's a 65mm piston and has a part number of 446 cast into one side. Any thoughts ? The other thing that surprised me is the cam profile. I'll have to dig into that a little further and see what gives...

I have a call into a respected machine shop that specializes in cranks and stroking on everything from marine use to modified garden tractor pulling engines, race bikes etc. Hope to hear back from them soon to see if they want any part of a ~8.4mm increase to the stock crank.

Now time to clean everything up and start mixing and matching parts to see what I can come up with.

[Dave8338]

OK... I have a solid quote from Crank Works out of AZ http://www.crankworks.com/ for $535.00 for the stroke, plus the shipping. I really want these guys to do the work BUT, I have one more shop in Northern MN, that I have to contact and see if they are interested. They are located 30 miles from where I grew up and if I know the boys from the "swamp", the'll crack the nut.

Question: Has anybody ever run a stroke where the piston clears the jug by ~1-1.5mm... just above the ring lands and 1/2 way into the head gasket? I know it sounds CRAZY, but I have a thought.

Also, as the crank work will take a month or more to get back, I may slap the original bottom end back together, along with a few new parts on the top that won't be used on the final project, and test out my new sprocket height. In final measure up, I'm still just shy of clearing the front swinger pivot and would like to throw a load at it and see how the new drive angle beats up on a relocated idler.

More to come...

[Dave8338]

Port matched the intake to the head last night. Contours worked out very nicely and just had to blend the bottom left side of the intake tube, to the head and do an #80 grit finish to the inside. Tonight, I hope to have the exterior of the new intake, polished to a mirror finish. Time will tell...

[Dave8338]

Received a few more parts in the mail.

The CRF 230 guides and tensioner arrived and I couldn't wait to see how things fit. The new tensioner "bands" will work. I will need to make a piece to secure the bottom end of the front band, from the looks of it.

Thought I would throw up a pic of the jug and freshly ported and exterior polished intake combo, sitting on its' new home.



MANY hours left on the test assembly and hand spun rotation BUT... at this point, I'm confidant that it will work.

Final compression will be in the 11.5:1 range with exception allowed for chosen gasket(s) material.

[oscarmayer]

nice web springs and retainers. I think that's a web cam as well. piston looks to be a wiseco of early design. a 10.25:1 comp model (if not wiseco a nice copy of one).

[Dave8338]

nice web springs and retainers. I think that's a web cam as well. piston looks to be a wiseco of early design. a 10.25:1 comp model (if not wiseco a nice copy of one).

I would agree. The "original" 185 cam, sure has the profile and fits the bill of a 375/375 - 280/280 Web cam as I have one of those from an Ebay score from a few years back. The piston looks like the current Wiseco 10.25:1 that I will be using in the final build. The tops are dished out, which adds more pre-load to the springs and should increase the close speed though that is speculation on my part. The springs are stiffer to compress, as well. Strange little bag of parts...

Now to tear the rest of the thing apart and send of my crank, piston, and rod. I'll pull the engine out of my 200 and run that in the project trike until the crank gets safely back home.

[oscarmayer]

Sounds sweet and like a fun build.


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[Jmoozy27]

Any update on this build?

[Jmoozy27]

Has anyone heard from him? I really liked the way this build was shaping up.

[DohcBikes]

Emailed him. Would like to know as well.