CT70 H Engine Rebuild Done...

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Wheelyking

New Member
Well... After around two months my engine rebuild is finished. I hope to have the engine back on the bike Sunday and fire it up. Thanks to all who replied to the questions I had during the rebuild.

One last silly question... The two manuals I have both show the plain nut and sealing washer for the cylinder head cover on the lower left side (as sitting on the bike) . I saw no evidence of any oil passage on that side but definitely on the lower right hand side. Even the cylinder head cover has the surface machined for that location and not the other three. So that's where I decided to put the plain nut and copper washer.

Am I right or wrong on that one?
Thanks Jim H.

Engine Complete 1 Crop.jpg
Engine Complete 2 Crop.jpg
 
hrc200x

hrc200x

Active Member
Copper washer is correct but think the normal nut needs to go on the other lower stud. The carb drain hose factory location was on the center case bolt on left side of motor, but maybe your running a different carb that will need the holder where you installed it. That engine looks like it should be under glass used for a end table in the house, nice job.
 
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Wheelyking

New Member
Thanks for the pointer on the drain hose and the nice comment. I'd like to leave the engine sitting on the table for another week so I can ogle it some more...
 
dirtbkr188

dirtbkr188

Active Member
I'm pretty sure the normal nut goes on the lower left stud, as you look at the engine, the oil passage stud, just as you have in the picture.
 
ctbale

ctbale

Member
When I was doing more of these I remember the parts book was wrong on the nut, or it never made sense to me. The oil goes up the lower stud on the clutch side so copper washer should be there, but from my cob webs memory the parts illistration showed it on the lower flywheel side? I just used 4 done nuts and tried to be sure none bottomed out. Someone here might know more on that.

Beautiful Engine!!!
 
kirrbby

kirrbby

Well-Known Member
Copper washer goes on the oil passage/lower right side/passenger side...with a acorn nut on it. The regular nut belongs on the lower left/driver's side stud.
That is Honda's design.
 
ctbale

ctbale

Member
yup! kirrbby is correct, and thats what the parts books show. (rusty memory I have) I just never understood the solitary hex nut ... longer stud?
 
kirrbby

kirrbby

Well-Known Member
Hex nut is said to be there to use for a jamb nut when you need to remove a stud...hex nut, jambed up against a acorn nut...
 
6

69ST

Well-Known Member
The theory is that it facilitates removal of two studs, allowing the cases to be split without tearing down the top end. I say "in theory" because the odds of a cylinder base gasket surviving R&R are slim-to-none. The cylinder has to be removed to replace a base gasket, which always involves scraping away residue of the old one.

FYI...Honda eventually went to 4 acorn nuts. I guess they figured that any shop capable of opening-up an engine would also have at least one M6 hex nut lying around...somewhere.:whistle:
 
ctbale

ctbale

Member
Dang, been working on these little engines for about 10 years, maybe done 20 rebuilds, did not know the "why" to the odd ball hex nut. Learn something new everyday!
 
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