Topic: Cb400F immobiliser issue

[Tommobb]

Hiya all,

Thank you in advance for any help

I bought a 1976 cb400f that was converted to a cafe racer. I bought it off a friend who didn’t use it for 5 years. Prior to that it was owned by a mutual friend who used it every day as a daily commute

I’ve cleaned the fuel out, changed the fuel pipes as they looked corroded and tightened the air filters as they were a little loose. The battery has been changed for a new power line gel sealed unit that displayed full charge on a battery charger

The bike did initially run for 20 miles but then starting spluttering to a stop. It restarted but then stopped again. The bike will start but then immediately cut out.

It has a motogadget mlock v2 on it. It should illuminate the lights to then allow an electric or kick start but it either briefly flashes and then goes out or stays on a little longer and allows the bike to start but it immediately dies.

Can anyone suggest ideas as to why the electrics are cutting out or how I can bypass the immobiliser to at least ride the bike as both locations I visit are very secure.

Thank you
Tom

[newday777]

Welcome aboard the forum Tom
There is a M-Unit section to ask how to do that in.

[Tommobb]

Thanks

[newday777]

As to it cutting out, I would bet you will need to remove the carburators and do a deep cleaning of them with an ultrasonic cleaner. 5 years of setting and you starting it up will have sucked in gummed gas into the internal ports of the carb bodies as well as the idle jets and emulsifier tubes that only a manual cleaning will clear out so it will run.

[Tommobb]

Thank you

When it cuts out all the electrics die too so I assume it’s the munit cutting out the circuit board?

When the immobiliser works (twice yesterday out of 100) it starts and idles easily off choke with no spluttering.

[newday777]

Important to put all information in to begin with so you can get a correct answer
It does sound like it would be either the immobilizer or a loose connection

[Nurse Julie]

Hi Tom.
As you're in UK, if you haven't done so already, maybe join the UK forum, as we're more local to you. I'm sure there are members on the UK site that have fitted M units who may be able to advise.
www.sohc.co.uk