Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: ChrisOnABike on September 02, 2014, 04:23:34 AM

Title: Where is the Battery??
Post by: ChrisOnABike on September 02, 2014, 04:23:34 AM

This might not be 750 specific, but that's what I'm working on so I'm asking this here.

In the linked photo, where is the battery?  Looks like a stock tank so I doubt it's inside, and I don't see any other place for it.  The tail looks way too small to hold it in there.

Does the bike even need a battery?  I know most systems run off the battery and the charging system just keeps it topped off.  Does this system work differently?

Thanks

http://bihamoto.sk/content/images/articles/73.jpg (http://bihamoto.sk/content/images/articles/73.jpg)

Title: Re: Where is the Battery??
Post by: AshimotoK0 on September 02, 2014, 07:28:57 AM

It may be that they have fitted a largish electrolytic capacitor, I did this when I was a student to my CB250K2. The 750 is 3-phase so less flickering of the lights at tick over probably. Incidently, I sussed a way of testing the regulator on the old CB twins 'pointless regulator'  a few weeks ago (CB250/350/450 etc). It's potted in epoxy but it's a Thyristor (SCR)  circuit which acts as a crowbar to voltages generated above the normal lead-acid charging voltage. The Brit bikes use a large Zener diode on a heatsink between the forks (Triumph) but it's not as elegant as the Honda (well Hitachi) solution as the Honda one has a very precise cut off at the set voltage (around 15v), which is not the case with a Zener diode.

Cheers ...AshD

Title: Re: Where is the Battery??
Post by: royhall on September 02, 2014, 09:42:31 AM

Wouldn't want to go any distance on that thing, the family jewels are at severe risk. You may also need a number plate for the UK. A non running show bike I think.

Title: Re: Where is the Battery??
Post by: Trigger on September 02, 2014, 09:54:12 AM

Yep, could be a non-running show bike. I have built some show engines with no internal parts.   

Title: Re: Where is the Battery??
Post by: ChrisOnABike on September 02, 2014, 03:04:50 PM

Wow, I would have never thought of a show bike that did not run.  Such a waste of good parts.  It also looks like there is a small switch just under the end of the tail section.

I think I would cut in a section of the petrol tank to house the battery.

The simple look of this particular machine is one I am using to base my own build from, but mine will probably need a battery.

Thanks for the replies.

Title: Re: Where is the Battery??
Post by: MarkCR750 on September 02, 2014, 04:44:22 PM

Could be using lithium batteries, you can get very slim versions that would fit under the seat hump of that bike, they work well but have no resistance to shorting so you have to be sure your electrics are in good order.
Here's a link to the Ultrabatt site.
http://www.ultrabatt.com/