Honda-SOHC

General => New Member Introductions => Topic started by: GT Graham on December 09, 2024, 03:25:53 PM

Title: 1980 CB100n
Post by: GT Graham on December 09, 2024, 03:25:53 PM: Hi Iâ€™m Graham

New here!
I have acquired a CB100n which I was told on purchase that it was running last year🤥.. after changing coil, rectify, points and plug, along with a new 6v battery I now have a spark, I have by past the fuel tank and have the carb set up on a separate fuel bottle.
Itâ€™s reluctant to start.
So am I thinking of checking the compression after checking the valve timing and all good it should start!..
is there anything I should be looking at before I go ahead?

This is new territory for me as Iâ€™ve always had 2 strokes
Cheers
Graham
Title: Re: 1980 CB100n
Post by: Bryanj on December 09, 2024, 03:39:04 PM: Blocked jets and passages in the carb
Title: Re: 1980 CB100n
Post by: SteveD CB500K0 on December 09, 2024, 03:48:30 PM: â€œLast yearâ€ is a minimum of 12 months sat with fuel in the carb. It will probably be sludge.

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Title: Re: 1980 CB100n
Post by: GT Graham on December 09, 2024, 04:33:23 PM: Thank you both..

Iâ€™ll get the carb off tomorrow and check it outâ€¦ 👍
Title: Re: 1980 CB100n
Post by: SteveD CB500K0 on December 09, 2024, 05:35:13 PM: I learned to ride on a CB100 on the car park of Bedford County Council offices in 1974.
It was an RAC/ACU scheme, off road for 16 year olds. I had a Raleigh Runabout at the time.

At 17, I went for a â€œmuch more powerfulâ€ CB125S

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Title: Re: 1980 CB100n
Post by: GT Graham on December 09, 2024, 07:26:55 PM: Itâ€™s the smallest bike Iâ€™ve owned apart from my mobylettes that Iâ€™ve have had over the years! I still have my first Moby an AV76, which I built years ago..
The little Cb100 takes me back tho..

You maybe be able to answer this, were these little cb100cc any good? 😁
Title: Re: 1980 CB100n
Post by: SteveD CB500K0 on December 09, 2024, 07:59:23 PM: From what I recall, they were identical to the 125, but with 25cc less.

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Title: Re: 1980 CB100n
Post by: GT Graham on December 13, 2024, 05:10:41 PM: Had a play in the shed and have had the little cb100 running, so I know now that compression is ok, even tho I have had the carb off and cleaned it it still only runs for a minute or so, so for Â£31.00 and postage I can get a replacement.

I recently bought some tank cleaner off Mad for bikes, has anyone used it, it says leave in the tank for several hours and shake every 30 minutes at room temperature.

Has anyone used this product? Or should I be looking at something different?
Title: Re: 1980 CB100n
Post by: Laverda Dave on December 13, 2024, 06:00:46 PM: Never tried that product and have always used DEOX-C from Bilt Hamber, excellent product and does what it says on the tin.
Title: Re: 1980 CB100n
Post by: GT Graham on December 13, 2024, 06:33:41 PM: Thanks for that Dave

just looked it up, I will order some, plus itâ€™s cheaper!

Thanks
Graham
Title: Re: 1980 CB100n
Post by: Sesman on December 14, 2024, 08:34:57 AM: Plus 1 on the Deox-C.
Title: Re: 1980 CB100n
Post by: Athame57 on December 14, 2024, 12:11:59 PM: Hello Graham
Welcome here, there's a goldmine of knowledge here to draw on too! ;D
Title: Re: 1980 CB100n
Post by: GT Graham on December 15, 2024, 10:48:20 AM: Thanks for the welcome.. Iâ€™m sure there is a lot of knowledge here!
Title: Re: 1980 CB100n
Post by: McCabe-Thiele (Ted) on December 15, 2024, 01:30:43 PM: Welcome Graham, good to read you've had it running albeit briefly.
Title: Re: 1980 CB100n
Post by: GT Graham on December 15, 2024, 07:46:49 PM: Thanks Ted.. a little way to go but itâ€™s getting there

Graham
Title: Re: 1980 CB100n
Post by: McCabe-Thiele (Ted) on December 16, 2024, 07:47:29 AM: Quote from: GT Graham on December 15, 2024, 07:46:49 PM
Thanks Ted.. a little way to go but itâ€™s getting there

Graham

Psychologically that a good early boost to morale, be great to read your progress.
Title: Re: 1980 CB100n
Post by: GT Graham on December 17, 2024, 06:38:03 PM: I have had a go with the tank cleaning solution from Mad for bikes, 500ml that has sat in the tank for 10 hours, itâ€™s removed some but not all, I have ordered some DEOX-C , Iâ€™m hoping that it will get rid of the remaining rust build up.

Hopefully the photo has attached
Title: Re: 1980 CB100n
Post by: McCabe-Thiele (Ted) on December 17, 2024, 08:53:14 PM: I used the now very expensive Evaporust. My 400 tank had petrol in it that had stood for over 10 years so was pretty bad inside.
I had two distinct steps to clean the tank interior.

1. Mechanical removal of the worst of the rust and gunk inside using what was gravel & with diesel as the lubricant.

2. Wash out Diesel then add Evaporust, rotating tank as needed. Left for a couple of days. New Evaporust for final clean.

Lots of alternatives such as Citric Acid. Time consuming process