Author Topic: Decoking engine 78 CB750  (Read 520 times)

Offline Mike1664

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Decoking engine 78 CB750
« on: May 30, 2018, 09:08:26 AM »
Hi Lads
First time posting so apologies if this is in the wrong place or I mess up. I have just bought a 1978 Honda CB750K, the bike is a none runner. Don’t know when last it ran, was wondering as these bike ran leaded fuel in the day, what are the consequences of running the bike on unleaded. Heard that decoking might be the correct course. Any advise welcome, first project bike and I’m no mechanic, got the bike to learn with, plus I love old school.

Regards
Mike

Offline Johnwebley

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Re: Decoking engine 78 CB750
« Reply #1 on: May 30, 2018, 09:56:19 AM »
Don't worry.the are happy using unleaded.
Change oil etc.Will need to strip jets
out of carbs and clean
Maybe when the plugs are out .a little  oil down the plug hole.after that.spin the motor over using starter. Check oil light goes out.

See if you get a spark.assemble and
It should go

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Offline hairygit

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Re: Decoking engine 78 CB750
« Reply #2 on: May 30, 2018, 11:39:40 AM »
De coking a Honda 4 stroke???? Never necessary unless it has been burning vast amounts of oil, but if it had, you'd be stripping the motor to assess and replace damaged/worn parts. They never require routine de coking like old Brit stuff or 2 strokes, they were designed to use unleaded fuel (Japan was very early at ditching lead in fuel) so as John said, oil & filter, clean carbs and jets, air filter, and ride!
If it's got tits or wheels, it's hassle, if it's got both, RUN!!!

Offline Mike1664

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Re: Decoking engine 78 CB750
« Reply #3 on: May 30, 2018, 02:47:30 PM »
Absolutely brilliant, thanks guys exactly what I was looking for, will defiantly do as recommended, oil change, plugs filter, pull the carbs clean and check jets, oh ye new battery, hopefully she should turn over. There’s no reason she shouldn’t,

At least I know where to go if she doesn’t.
Thanks

Offline haynes66

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Re: Decoking engine 78 CB750
« Reply #4 on: May 30, 2018, 07:11:57 PM »
i think i recognise your forum name from another forum. what else do you/did you ride?
honda firestorm
silverwing 600 scooter
honda britain project
phil read rep project
YGS1 80cc yamaha
LE Velocette

Offline SteveD CB500K0

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Re: Decoking engine 78 CB750
« Reply #5 on: May 30, 2018, 07:39:57 PM »
Maybe he likes beer.

OK, sorry if I upset anyone by referring to lager and beer in the same sentence…


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2022 Tiger Sport 660
1971 CB500K0

Offline Mike1664

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Re: Decoking engine 78 CB750
« Reply #6 on: June 03, 2018, 07:22:39 PM »
Sorry mate, haven’t been on any other forums before, this is my first. It takes me ages just to figure out how to reply.  Hahahahaha. Other than the Honda, which isn’t in the road or working at the moment, I rode a Triumph 1050R speed triple. However. Had plenty bikes, to many to list really.

Offline SteveD CB500K0

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Re: Decoking engine 78 CB750
« Reply #7 on: June 03, 2018, 07:56:08 PM »
Go on and list them.

I’ve never owned a Speed Triple but have had 5 x 955 Sprints, a Tiger 1050 and 2x Tiger 800s

And a 500/4


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2022 Tiger Sport 660
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Offline Mike1664

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Re: Decoking engine 78 CB750
« Reply #8 on: June 03, 2018, 08:07:12 PM »
I like those Tigers different ride style. The 1050 is my second Triumph, I came off the pocket rockets, told myself it was time to slow down so got a Speedmaster but didn’t get along with it, but liked the build quality of Triumph so got the 1050. Having said that I would still like a Bonny.

 

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