Honda-SOHC
General => New Member Introductions => Topic started by: Ariel-KH-500 on May 07, 2026, 08:34:27 AM
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just recently joined the forum, based in kings Lynn Norfolk owning a 1978 cb400/4 which I have had for 2years. will post in the 400 section soon as having problems when trying to start the bike when its not been used for a few days will be grateful for any advice from more experienced members.
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Hello from Orkney and welcome to the forum from another 400/4 owner - there are lots on here who will chime in to help. One quick check that will cost nothing is to see if there are resistor plugs fitted AND resistor caps. This combination often causes bother - use only one or the other but not both. Like the handle too - do you still have the Ariel?
Ian
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Welcome to the sohc community.
An easy check is when it has stood for a few days, squirt some Easy start into the air cleaner box, if it starts immediately I would then start with basic checks, compression, ignition timing, check out advancer is working.
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Hello and welcome to forum from another Orkney member. These bikes don’t really like sitting around! Think it’s a characteristic of these fours that needs a couple of cylinders firing up to waken the other 2 cylinders. At least mine do anyway.😜
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Hello and welcome to forum from another Orkney member. These bikes don’t really like sitting around! Think it’s a characteristic of these fours that needs a couple of cylinders firing up to waken the other 2 cylinders. At least mine do anyway.😜
Same with mine. Once warmed up starts first time. Just doesn't like being left for a week or more.
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Welcome.
One thing I always do I turn off the fuel tap about a mile from home. The next time you come to start it, there's a fresh glug of fuel into the carbs that seems to help a bit. These old bikes do loose a bit of goodness from fuel sitting in carbs due to evaporation if they're stood for a while.
The other thing to check with cold start woes is the choke flaps fully closing when required. For fast idle when cold, the choke lever should also lift the throttles by a very small amount and you need the choke lever at least quarter setting to hold a fast idle for half a minute then ease it off as it warms up and the idle increases.
Don't touch the throttle when on full choke it won't help.
Regards
Dave
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Welcome here Ariel, lots of knowledge to call on here. I ride a CB400F2. ;D
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Don't touch the throttle when on full choke it won't help.
Strange, it does with me sometimes, maybe there's something needing attention? ???
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Mine won't even pop off with any throttle when starting it on full choke and once running it needs about 5 seconds before you dare to touch the throttle. Bikes do have their own personality I guess. It usually fires up 3rd kick from cold most times so I'm not too worried.
A new battery is still on the job list.
Regards
Dave
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Welcome to the forum from around the corner in Lincolnshire.
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Welcome to the forum from another 400/4 owner. I can't add anything to what has already been suggested only to make sure the air cleaner is clean and not damp as they are paper and will absorb moisture in the air.