One Mans Junk.... '72 CS5E (RD200) Build.

[Jim]

Pressed in the right side crank bearing and seal, and the right countershaft bearing.

I trashed the 3 screws holding the "oil scoop" plate when I took it apart. Replaced them with 3 NAS 10-32 low profile screws, loctited in. Something to file away in the grey matter.... M5-.7 and 10-32 fasteners are interchangeable for all practical purposes.

Sometimes you have to get creative when you don't have a socket big enough for the bearing. End grain hardwood....

That's all the new bearings I've received so far. Back to waiting.

 

[Kevin Werner]

I have replaced a few tapered bearing sets in my time. When I remove the outer race of the old set, I take it to the sander/grinder and gently "face" the outside until it can be inserted into the seat without binding. Then I use that old outer race as the drift to seat the new bearing race after the hardwood has the bearing race flush and there is still 1/16ths to go to fully seat the race. A sander works well because you can keep even enough pressure on the whole outer face of the race as you roll it. I know this is not germane to rollers unless you have a tapered race of matching diameter.

 

[Jim]

All new bearings pressed in, except for the left output shaft bearing which felt like a new one. Hope I don't come to regret that decision.

All new seals pressed in except for the left crank seal. It needs to stay out until the crank is pulled out through the bearing

Can't reassemble the halves until the labrinth carrier o-rings show up from Sumo Rubber. Not their fault, I was late ordering 'em.

 

[Mailman]

Man! Those look like brand new cases!

 

[MrBultaco]

Yeah they do...looks like cases you would be working on Bob.

 

[Jim]

Still waitin' on seals from across the pond, so I thought I'd do a writeup on the tooling I made to pull the two crankcase halves together. Or more correctly, draw the crank out through the bearing inner races.

The right side of the crank is threaded for a 12 X 1mm nut. This side is the only expenditure I had to make.... a 5 pack of 12mm nuts for $5. Scrounged a piece of tubing, slotted it in 6 places and tapped the nut into it.... then TIG'd it in place. On the other end I threaded a long bolt (5/16" maybe... ) onto a washer and TIG'd that into place.

This threads onto the right side of the crank.

For something to pull against, I scrounged another piece of tubing about the same diameter as the bearing inner race. Welded a washer to the end and it will work for both sides of the crank.

The left side of the crank is an odd sized hole, threaded for a 7 X 1mm bolt. Finding an odd size like that was just blind luck... I found a few (allen heads) in a scrounge can of hardware. Welded one onto a larger (1/2") bolt.

This threads into the left side of the crank.

The larger tube works for both sides.

And here we all are....

I'll use washer stacks to "shim" the pullers as required. For a 5 buck investment, I'm plum tickled.
I suspect the reason the crank was bent to hell and back was because someone tried to assemble the two case halves without the proper tooling.
Problem solved. Ebay has some generic tooling for about 50 bucks... that might or might not have worked. My way was funner.

 

[jpdevol]

Awesome! With the washer stack between "outer" and crankcase, it should work like factory

 

[Mailman]

Very nice work there Jim!

 

[WideAWAKE]

Very nice!!!

 

[kshansen]

Just a idea about this RD200. I had one back in the day that had a bit of a strange noise, took it for a short ride to see if I could determine what was making the noise. About a mile from home I figured out it was something important. Had a bit of time to think about next step while pushing it back to the house!

After starting to disassemble the engine found that the gear on the Auto-lube pump had come off. Seems two-stroke engines don't like running on straight gas! Surprising that the "only real damage" was the big end rod bearings.

I checked with the local dealer and at that time con-rod kits were available for $25 each and they could replace them for $25 per cylinder. Then they said they could sell me a complete factory built crankshaft assembly for just over $100.00 which is what I got.

Forget what held that gear on, might be a nut that I might have used Loctite on to prevent it coming off again.

 

[Jim]

Checked on the seals this morning and the Post Office still said something to the affect of still stuck in customs. Imagine my surprise this evening when the mailman showed up with the seals.
Awesome!!

Cleaned up the crank and installed the seals. I think I forgot to mention that I kept working on the crank and finally got the runout down to where it was just barely discernable on the runout gauge. I'd say somewhere around 0.0002" (two - ten thousands). The book calls for less than 0.0012". I'll take it...

Set the crank in the left case half and screwed on my homemade tooling. Worked jus' like the factory stuff. Pulled the crank in easy peasy.

Made a (wood) platform for the left half to set on and installed the tranny.

Ran a bead of sealant around the left case half, set the right half in position and installed the tooling. It pulled the crank out through the bearing purty as you please.

And here we are. Crank spins nicely. Tranny spins nicely and all the gears work. If anything... it was all pretty anti-climatic.... everything went together just as it should.

It's almost midnight and I had to force myself to quit for the night. Buildin' engines is too much fun.

 

[Raymond]

And here we are. Crank spins nicely. Tranny spins nicely and all the gears work. If anything... it was all pretty anti-climatic.... everything went together just as it should.

'course it did. All your planning, making special tools, plus experience of and delight in building engines, none of us expected anything less. Great work!

 

[Adamc]

Checked on the seals this morning and the Post Office still said something to the affect of still stuck in customs. Imagine my surprise this evening when the mailman showed up with the seals.
Awesome!!

Cleaned up the crank and installed the seals. I think I forgot to mention that I kept working on the crank and finally got the runout down to where it was just barely discernable on the runout gauge. I'd say somewhere around 0.0002" (two - ten thousands). The book calls for less than 0.0012". I'll take it...



View attachment 227706



Set the crank in the left case half and screwed on my homemade tooling. Worked jus' like the factory stuff. Pulled the crank in easy peasy.



View attachment 227713




Made a (wood) platform for the left half to set on and installed the tranny.



View attachment 227708



Ran a bead of sealant around the left case half, set the right half in position and installed the tooling. It pulled the crank out through the bearing purty as you please.



View attachment 227709



And here we are. Crank spins nicely. Tranny spins nicely and all the gears work. If anything... it was all pretty anti-climatic.... everything went together just as it should.



View attachment 227712

View attachment 227711



It's almost midnight and I had to force myself to quit for the night. Buildin' engines is too much fun.

Fantastic work Jim; and very creative with the tooling!

 

[Downeaster]

Jim, first picture: What are those rubber-looking things with the "legs" in the center of the crank? Seals of some sort? Where do the "legs" go when assembling?

 

[kshansen]

Jim, first picture: What are those rubber-looking things with the "legs" in the center of the crank? Seals of some sort? Where do the "legs" go when assembling?

Not Jim here but if you look at the picture below there is a "chunk of aluminum" that separates the two crankcase halves that has grooves in it for those legs. Need to remember this is a two stroke so can't have the mixture from right getting into the left and vice a versa!

 

[Downeaster]

I figured it was something like that, but I couldn't see where the legs went.

Thanks!

 

[jpdevol]

Top-shelf stuff for sure! Ya threw me a bit on where you were placing a washer stack. For some reason, the original factory assembly tool had a large flange at the end of the outer sleeve - there was only one such tool for all vertical models IIRC - so they intended it to rest against the case, rather than the bearing. I never quite understood the "why" of that design; if you put a bearing on a shaft, you try to work the inner race, if you put a bearing in a case, you work the outer race. Your tool supported the main bearing directly

 

[Mailman]

Terrific work Jim, I can’t believe how true you were able to get that crank with nothing but that big caveman lead hammer! That motor is going to be a thing of beauty!

By the way , how could you doubt the Post Office? The Mailman always delivers!

 

[Jim]

Top-shelf stuff for sure! Ya threw me a bit on where you were placing a washer stack. For some reason, the original factory assembly tool had a large flange at the end of the outer sleeve - there was only one such tool for all vertical models IIRC - so they intended it to rest against the case, rather than the bearing. I never quite understood the "why" of that design; if you put a bearing on a shaft, you try to work the inner race, if you put a bearing in a case, you work the outer race. Your tool supported the main bearing directly
View attachment 227728

Yeah, one of the reasons I didn't spring for the Ebay generic stuff... other than bein' a cheap bastard... was because of exactly that. You're drawing the crank out through the inner race... which is a very tight fit by the way... and pulling against the case to do it. So the loading goes from the outer race, across the balls and to the inner race. It all feels counterintuitive and has the very real danger of damaging the bearing.
I reasoned that since we're trying to push the bearing onto the crank, why not push on the part we're trying to move... the inner race. Which is what I did.

 

[Jim]

Here ya go JP. Looks like you're correct... one size fits all tooling set for all the vertical split cases. If I'm lucky, the tooling I made will also fit my DT250 engine. Fingers crossed.

Here's outta the CS5 manual.