Honda-SOHC
SOHC.co.uk Forums => CB500/550 => Topic started by: faiz_mur on January 23, 2021, 04:12:27 AM
-
Hi Need advice
My cb500k
All this while was running ok
No issue plugs colour was good
But recently all the 4 plugs have black dry carbon black
I did check n replace ignition coil
Spark plugs caps and plugs
Did check ohm resistance using multimeter
Bike using CDI
Did do Static Timing to F mark
Did valve clearance and cam chain adjustment
Need advice if its due to main jet can it been suddenly ?
I mean all this while was good with same jet
Carb fuel level was good too
Thanks
-
Anything under the seat that could hinder air intake? Has the engine been idling for a long time? What plugs do you run?
-
Choke?
-
Ideally you check the ignition timing with a strobe at +4.500rpm.
Sent from my SM-A750FN using Tapatalk
-
Have you checked the air filter?
-
I'd be inclined to check the previously mentioned air filter restriction (under seat inlet). For it to happen suddenly is unusual for an air filter to suddenly get clogged - but its pointing to that area as all 4 cylinders affected.
Only other common part to all 4 cylinder (although obviously timed differently) is CDI - I don't know anything about the workings of those but maybe another forum member could advise if the CDI could affect all 4 cyclinders at once
-
I'd be inclined to check the previously mentioned air filter restriction (under seat inlet). For it to happen suddenly is unusual for an air filter to suddenly get clogged - but its pointing to that area as all 4 cylinders affected.
Only other common part to all 4 cylinder (although obviously timed differently) is CDI - I don't know anything about the workings of those but maybe another forum member could advise if the CDI could affect all 4 cyclinders at once
No SOHC four (except CB650) came with CDI, they had points and condensers. Highly unlikely to be an ignition related fault on all 4 cylinders. As previously suggested the sudden occurrence points to restricted air intake or sticking choke flaps.
Sent from my POT-LX1 using Tapatalk
-
I'd be inclined to check the previously mentioned air filter restriction (under seat inlet). For it to happen suddenly is unusual for an air filter to suddenly get clogged - but its pointing to that area as all 4 cylinders affected.
Only other common part to all 4 cylinder (although obviously timed differently) is CDI - I don't know anything about the workings of those but maybe another forum member could advise if the CDI could affect all 4 cyclinders at once
No SOHC four (except CB650) came with CDI, they had points and condensers. Highly unlikely to be an ignition related fault on all 4 cylinders. As previously suggested the sudden occurrence points to restricted air intake or sticking choke flaps.
This one has had one fitted previously.
Sent from my POT-LX1 using Tapatalk
-
Hi this bike using CDI which was installed by previous owner
It came with cdi black box aswell
I did timing check staticly havent try dynamic timing yet..
The bike doesn have air filter
Its just empty at the filter box area
but ya i did keep tools bag there
Might be chance the make air restricted
I will try again..riding removing the tools bag
Thanks everyone
-
Hi some update
I did adjust float height no 1 and 4 carbs because it overflow.
I did replace my rectifier
And ya did few mile ride and there was no more carbon
Im not sure yet whats actually caused
This
Thanks everyone