Honda-SOHC

General => New Member Introductions => Topic started by: wrighty on June 20, 2016, 08:51:25 PM

Title: new member with a cb125s
Post by: wrighty on June 20, 2016, 08:51:25 PM

Hi everyone I'm mark from a little village called edwinstowe in Nottinghamshire. I purchased a complete basket case up in April this year as I'm a big fan of hondas having had quite a few in the past. This bike was in a complete bad state but mainly just surface rust. The bike came with plenty of spares so I had lots of salvagable parts. The engine though was seized so it was completely striped and fully rebuilt with new crank and 190cc oversize kit.....


This is the bike when I collected it

(http://i1036.photobucket.com/albums/a442/marksambailey/Mobile%20Uploads/20160428_111142.jpg) (http://s1036.photobucket.com/user/marksambailey/media/Mobile%20Uploads/20160428_111142.jpg.html)

And then at home in my shed

(http://i1036.photobucket.com/albums/a442/marksambailey/Mobile%20Uploads/20160428_200458.jpg) (http://s1036.photobucket.com/user/marksambailey/media/Mobile%20Uploads/20160428_200458.jpg.html)

(http://i1036.photobucket.com/albums/a442/marksambailey/Mobile%20Uploads/20160428_200443.jpg) (http://s1036.photobucket.com/user/marksambailey/media/Mobile%20Uploads/20160428_200443.jpg.html)

Few spares


(http://i1036.photobucket.com/albums/a442/marksambailey/Mobile%20Uploads/20160428_200432.jpg) (http://s1036.photobucket.com/user/marksambailey/media/Mobile%20Uploads/20160428_200432.jpg.html)




Ok how it looks now...minus exhaust and drive chain

(http://i1036.photobucket.com/albums/a442/marksambailey/Mobile%20Uploads/20160620_151732.jpg) (http://s1036.photobucket.com/user/marksambailey/media/Mobile%20Uploads/20160620_151732.jpg.html)

(http://i1036.photobucket.com/albums/a442/marksambailey/Mobile%20Uploads/20160620_151753.jpg) (http://s1036.photobucket.com/user/marksambailey/media/Mobile%20Uploads/20160620_151753.jpg.html)

(http://i1036.photobucket.com/albums/a442/marksambailey/Mobile%20Uploads/20160620_151810.jpg) (http://s1036.photobucket.com/user/marksambailey/media/Mobile%20Uploads/20160620_151810.jpg.html)

(http://i1036.photobucket.com/albums/a442/marksambailey/Mobile%20Uploads/20160620_151810.jpg) (http://s1036.photobucket.com/user/marksambailey/media/Mobile%20Uploads/20160620_151810.jpg.html)

190cc cylinder left....125cc cylinder to right

(http://i1036.photobucket.com/albums/a442/marksambailey/Mobile%20Uploads/20160602_100942.jpg) (http://s1036.photobucket.com/user/marksambailey/media/Mobile%20Uploads/20160602_100942.jpg.html)


If anyone could give me advice about setting points and ignition timing I'd be most grateful...

Thanks

Title: Re: new member with a cb125s
Post by: Bryanj on June 21, 2016, 05:41:41 AM

All honda points are set at 0.35mm or 14 thou when on the top of the cam and should open as the "F" mark on the alternator lines up with the static mark on the case, if a battery ignition best way to tell this is with a bulb connected accross the points spring and ground so the bulb lights up as the points open, if not battery use a multimeter to measure resistance which goes infinite as the points open

Title: Re: new member with a cb125s
Post by: wrighty on June 21, 2016, 07:58:21 AM

Quote from: Bryanj on June 21, 2016, 05:41:41 AM

All honda points are set at 0.35mm or 14 thou when on the top of the cam and should open as the "F" mark on the alternator lines up with the static mark on the case, if a battery ignition best way to tell this is with a bulb connected accross the points spring and ground so the
 bulb lights up as the points open, if not battery use a multimeter to measure resistance which goes infinite as the points open

Thanks for the advice....

1 question does the points plate have to be moved to a specific place or lined up anywhere

Thanks

Title: Re: new member with a cb125s
Post by: SteveD CB500K0 on June 21, 2016, 09:10:22 AM

Hi Mark

My first bike was a CB125S...

Can you sort out the links for your pictures? I'd like to see them.

There has been discussion on here before about the 180cc kits that were sold in the 70's. My room-mate at Uni had one in 1978 - they were seriously under-engineered  :(

Steve

Title: Re: new member with a cb125s
Post by: florence on July 01, 2016, 10:30:03 AM

I had one of those and it was brilliant fun to ride.  Later I had another and it kept overheating and seizing.  I didn't ever find out what it was but I suspect the camshaft bearing was worn causing the timing to be all over the place.

Extraordinary restoration job you have done, I admire your courage.  Welcome to the forum.

S

Title: Re: new member with a cb125s
Post by: Bryanj on July 01, 2016, 09:43:19 PM

Set gap first then move points plate to set timing BUT recheck gap as plate is rarely a tight fit in casing, usually takes 3 or 4 resetings to get both correct at same time

Title: Re: new member with a cb125s
Post by: florence on July 02, 2016, 10:38:25 AM

if you don't have a bulb and a wire then a transistor radio (not digital) tuned between stations (so all you can hear is white noise) will emit a click sound as the points open.  not joking, it's brilliant.

Title: Re: new member with a cb125s
Post by: matthewmosse on July 02, 2016, 02:40:30 PM

Nice job on that bike, very brave to take that on. My cousin (2nd time removed) did a 100cc version of one of those up last year as his first bike, thanks to the bad influence of visiting me and having a go on my old Rebel 125. I know very little about these bikes but might be able to get a few pointers if you get stuck though he is still learning himself, and answers do get lost in translation. Seems you have some decent advice now anyway so hopefully will be up and running.