bike wont re-start...engine turns slowly?

[cicatrez]

Not my bike, but the bike of a friends.
He starts up the bike from cold, and it starts up fine, leaves it to warm up for afew minutes. Switches it off for not even a minute.
then attempts to start the bike up again.
However, it doesn't start up at all. you can hear the normal whining/grinding noise from the engine turning. but this time it is alot slower. Electrics seem to be fine as all the lights are bright (but obviously dim abit when trying to start).
oil light comes on when trying to start it for the second time
what could the problem be in this case? as this happened on 2 occasions.
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'02 Honda City Fly

[P.addy]

What bike?

[cicatrez]

honda CB400sf NC31.
I know craig23 has the same kind of bike.
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'02 Honda City Fly

[Alexio]

[cicatrez]

unknown, as the bike was just bought.
are there engine flush oils that can be used on bikes?
or just do a regular oil change?
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'02 Honda City Fly

[lonner]

the oil light is coming on as the rate the engine is turning over is slow so that answers that (its not an oil change issue)

is the battery in good condition?
the reason i ask is if its been on a charger then taken out for a ride the battery may be knackered so it starts first time and then hasn't got enough juice in it to do it again.

a poor battery may appear fully charged on the charger when its in fact shagged.

that is first thing to check along with connections and also the startor relay conections.(clean and tight)

plus as with all hondas you need to check that the charging system is working too so check volts at the battery with the engine running.

you are looking for 13-14.5 volts or there abouts.

hth

[P.addy]

im with guy above.
my battery has stopped recharging in the GS500...as has my other battery.. i have something wrong somewhere.

I can start up on the button...once thru my journey, rest are bump starts
look a tit at the garage, trust me.

Try a full recharge of the battery/test it when its running..if you get it running again.

the 400SF are fantastic...very fun..so enjoy it!
obviously, derestrict it if it hasnt already been done

[cicatrez]

thank you very much zzr lon I'll pass on the info.
we dismissed it being the battery because all the instrument lights seemed bright. but we will look into it further.

this incident happened twice.
yesterday, started the bike, and warmed it on idle for 5minutes, rode up the road and back. got off and switched off engine to go inside. came back outside minutes later and the bike wouldn't start. so we just left it.

and today, like i mentioned above, it started up 1st time. but when starting it up again later (hadn't even gone for a ride), it didn't start up.

also, by any chance.. does anyone know where one can find servicing or manuals for the honda CB400sf?? not keen at all on the price tag of £75-100 we were quoted by a dealer who said they could import one from japan (and no mention if its in english or not)
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'02 Honda City Fly

[lonner]

[cicatrez]

having a quick look on ebay i tried putting in cb400sf, cb400 sf, NC31 and can't find any service manuals or CD's.
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'02 Honda City Fly

[mad4it028]

https://shop.ebay.co.uk/?_from=R40&_trksid=p3984.m38.l1313&_nkw=cb400+manual&_sacat=See-All-Categories
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always looking to buy bikes crashed ,unfinished projects,none runners pm me
currently riding kawasaki z1000 only bike ive ever loved

[lonner]

[cicatrez]

thanks again zzr hon. does the cb400sf share parts with any other bikes?
that ebay listing makes me wonder if it's any different from this one.

https://hondacb400.myfreeforum.org/CB400SF_Workshop_manual_about3.html

which we downloaded, and tbh, the translation is pretty poor
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'02 Honda City Fly

[lonner]

[cicatrez]

hows about doing a voltage drop test?
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'02 Honda City Fly

[lonner]