OOps, always worrying!

[Oddjob]

The regulator has 2 bolts holding it onto the plate, both are M6 x 16mm. Measure the bolt and that will mean we can tell you exactly where it's come from.

[McCabe-Thiele (Ted)]

I'm pretty sure my regulator has two bolts securing it.
One at the top, one at the bottom.

[exvalvesetdabbler]

Just add the bolt to your jam jar of other surplus fasteners.  One day it will come in handy.

Regards
Dave

[Otis]

Looking at the size of that washer, could it be one of those bolts that have a rubber cushion beneath, and do you remember how many of those you fitted back?

If you go an inch up from number 21 and go right you will see a hooked bracket that holds the regulator. There is no second fixing for the regulator on my bike

[Athame57]

Looking at the size of that washer, could it be one of those bolts that have a rubber cushion beneath, and do you remember how many of those you fitted back?

If you go an inch up from number 21 and go right you will see a hooked bracket that holds the regulator. There is no second fixing for the regulator on my bike

Are you sure you aren't responding to Oddjob? 

[Bryanj]

I am sure the regulator should be on two bolts, the rubber will be solenoid or flasher relay

[McCabe-Thiele (Ted)]

It's a long shot, when you say your regulator is held on with one bolt, you do mean the regulator, not the rectifier?

[Otis]

It's a long shot, when you say your regulator is held on with one bolt, you do mean the regulator, not the rectifier?

I don't believe there is a seperate rectifier? Aren't the regulatorss and the rectifiers combined?

[exvalvesetdabbler]

Looking at the pictured posted, it looks like a combined reg rec unit so the fixing won't be standard unless there's an adapter bracket.

Regards
Dave

[exvalvesetdabbler]

Here is the original regulator, bolted to the air filter box. [ Guests cannot view attachments ]

Regards
Dave

[exvalvesetdabbler]

Ah ha. Looks like someone has relocated the OEM rectifier. That lump with fins looked like an aftermarket combined unit.  I can see the original regulator in the most recent image.

The original   rectifier on the 400 was on the other side
[ Guests cannot view attachments ]

Regards
Dave

[McCabe-Thiele (Ted)]

It might not be an issue, I thought the rectifier was mounted where it was originally to aid air flow/cooling.

[Otis]

Here is the original regulator, bolted to the air filter box. (Attachment Link)

Regards
Dave

OK, mystery solved.

I'm a bit confused about regulators, rectifiers and combined units but if the unit with the white strip containing green and black rectangles is the original regulator then that is what I have and the bolt fitted the upper fixing. It was concealed behind a part of the harness so I missed it. I must have started to remove this unit and then realised it didn't need to come out.

Anyway, thanks to all for the help and guidance which as always, is educational.

[McCabe-Thiele (Ted)]

Here is the original regulator, bolted to the air filter box. (Attachment Link)

Regards
Dave

OK, mystery solved.

I'm a bit confused about regulators, rectifiers and combined units but if the unit with the white strip containing green and black rectangles is the original regulator then that is what I have and the bolt fitted the upper fixing. It was concealed behind a part of the harness so I missed it. I must have started to remove this unit and then realised it didn't need to come out.

Anyway, thanks to all for the help and guidance which as always, is educational.

If a combined unit has been fitted,  the one part replaces the original Rectifier and Regulator.
Yours has what looks like the original Regulator, it's held in place by the top and bottom bolts via rubber mounts fitted to the regulator.

The Rectifier is the unit with the alloy fins in your photo.
It might be worth checking if you have the lug on the right side of your frame where the original Rectifier is bolted in place by one bolt.
Seems unusual that yours is fitted where it is,  makes me wonder if the wiring lead is too short to mount it in the correct place. Might be worth investigating a possible move to a cooler position on the right side of the frame.