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Discussion Starter · #21 ·
I was able to locate another kick start shaft. I have two now, one bad one, and one very bad one. I will take the very bad one and do a cut and shut with the new shaft shown in the first picture. It is a new kick shaft from a C90 I think, and it's the same 14mm diameter and splines. If I keep the circumferential weld in the right area I won't even have to skim it down. I'll make a male/female location pin on the two parts in the lathe, put a heavy chamfer on the parts, and tig them together.
 

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Discussion Starter · #22 ·
Font Number Parallel Screenshot Document



Just a tally of costs so far. Not included are items to complete the 12V conversion, like lights, horn, starter solenoid, battery, etc.
 

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Hello there,
I'm going to do this exact conversion too but not started it yet, as you seem a lot more engineering/mechanically based than I am could i ask a couple of things? Is there any mechanical reason you didnt use the twin carb set up on the original CB200 engine and as I read it from above I'm going to need a set of CB200 top mounting brackets - do you know who might do these? and finally have you married up the engine in the frame yet re the alignment of the drive and back sprockets?
 

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Discussion Starter · #24 ·
Hello there,
I'm going to do this exact conversion too but not started it yet, as you seem a lot more engineering/mechanically based than I am could i ask a couple of things? Is there any mechanical reason you didnt use the twin carb set up on the original CB200 engine and as I read it from above I'm going to need a set of CB200 top mounting brackets - do you know who might do these? and finally have you married up the engine in the frame yet re the alignment of the drive and back sprockets?
Hello Micker!
I want to keep the CD175 head because the single carb is simpler, and I won't have to rework the air filter/sidecovers etc. The two engines seem to have the same HP ratings (17 hp at 9000 rpm) so it didn't seem necessary to use the CB200 head. Also, I just wanted a project, and dropping in a CB200 engine wasn't interesting enough.
The top mounting brackets I will do myself. They are stamped steel plates, but I could make flat steel plates with spacers to make up the offset, and because it's under the tank no one will see it anyway.
I have not married up the engine and frame, but the drive alignment is the same as the major crankcase dimensions are the same between the CB/CD.
I need to receive the vapour blasted parts, send out the cylinders for rebore, and receive all my gaskets, then I can start the engine build, which I will document. I should be done by springtime so keep checking back!
 

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Hello there,
I'm going to do this exact conversion too but not started it yet, as you seem a lot more engineering/mechanically based than I am could i ask a couple of things? Is there any mechanical reason you didnt use the twin carb set up on the original CB200 engine and as I read it from above I'm going to need a set of CB200 top mounting brackets - do you know who might do these? and finally have you married up the engine in the frame yet re the alignment of the drive and back sprockets?
These are the bits you need.

HONDA CB200 CB200T - ORIGINAL TOP ENGINE MOUNTING BRACKET AND BOLTS | eBay

Otherwise, a straight swap with a CB175 engine, into a CD175 you'd need the matching air fiters.
 

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don't worry you've been 'bookmarked' - and thanks for both replies, all seems to make perfect sense. Thanks for the link for the brackets I M, very much appreciated. Anyway good luck with it all and I will checking in regularly
 

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Discussion Starter · #30 ·
Quick question to all:
Should I prime/paint the engine crankcases? I have some VHT Engine Enamel (primer, base, clear) ready to go. It's the aluminium colour.
How did these bikes come originally? Were only the side covers painted, and the crankcases left natural? Was everything painted? Were the cylinders and head painted?
I thought I could clear coat the crankcases, cylinder, and head if they came natural from the factory.
What are your thoughts?
 

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Discussion Starter · #31 ·
Crankcase oil mods. The CD case has a 3.0mm hole on the clutch side, and a 1.5mm (ish) hole on the alternator side. The CB case seemed to have a 1.5mm hole on the clutch side only. I have modified the CB case now to have the same holes as the CD case.
 

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Discussion Starter · #32 ·
Also, I decided to paint the crankcases separately. I was considering building the bottom end and painting all the covers and cases at the same time, but that would get paint all over all the bolt heads and gaskets. I used Frog tape to mask the cylinder opening and the drain plug. I then put the engine in the oven to warm it up to about 60 degrees C. It is about 8 degrees in the garage, so no good for painting. With the warmed cases bolted together, I used cardboard to mask the clutch and alternator sides, and painted 3 coats of primer, and let it dry for 20 mins. They back into the oven for 100 degrees C for 20 mins. This is all per the instructions on the VHT documentation. Today I will repeat the process but with the base colour.
Last pic is the engine sleeping on the bathroom floor overnight. I didn't want to put it back in the cold garage, so it stayed in the spare bathroom.
 

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How did these bikes come originally? Were only the side covers painted, and the crankcases left natural? Was everything painted? Were the cylinders and head painted?
Originally, only the two side covers and the starter motor were painted, rest of the engine left bare aluminium, not even lacquered as the fork bottoms were.
 

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Discussion Starter · #35 ·
Originally, only the two side covers and the starter motor were painted, rest of the engine left bare aluminium, not even lacquered as the fork bottoms were.
Hello IM, thank you for that. I suspected that may be the case. I decided not to go with originality but with ease of maintenance. I wouldn't want the cases oxidising or degrading somehow.
 

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Discussion Starter · #37 ·
All tig welded up. It is now a little bent after welding, but can fix that with a brass hammer. All in all, very good.
Many thanks to my patient neighbour who donates his time and lathe for my motorbike projects!
 

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Discussion Starter · #40 ·
And by the way, anyone interested in this thread may also be interested in another forum blog I have going where I put a KTM 690 engine in a CB550 frame, see link below

 
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