Problem before ride today

[Angela Collen]

Hi all, started up honda cb400nc superdream 1983 for quick ride as nice weather this morning and started on one cylinder and then iddled and then on two cylinders, ran lovely no problems, so smooth, so is this because I only use it sparingly and oil needed time to get to 2nd cylinder, I also hadn't started it in while so maybe oil dried up in 2nd? Your experience needed to tell me if I am talking rubbish or have another job for winter, thanks for your time

[Ian Frog]

First thing to ask is what is the fuel you are using like ?

It may be worth changing it for fresh and if you are storing the bike over winter might be worth draining completely (including carbs) to prevent the seperating and formation of water at the lower points.

If fuel fresh and ok then start to look at battery health then all the usual things that affect sparks on older Hondas.

Cheers

Ian

[Angela Collen]

I use aspen have all summer, it doesn't go off,that's why I use it (the motorcycle one not lawn mower one) plugs all new, new battery, the bike was a little damp when i got it out of shed, I have oxford full cover in brick shed, but like everyone I still need to dry it off every so often, puzzled as starts easily first time but just took minute to run on both cylinders, then a dream no issues, know its classic bike, where to check next? Thanks for your time Ian

[Nick the wanderer]

Hi,

if you are happy with the fuel quality then check the carb bowls are filling ok. My first thought was fuel starvation, do you keep it on a side stand? When on the mainstand you should be able to drain the fuel from underneath the carbs. My guess is they are full now.

I think they are cv carbs if I remember correctly, one side may have just evaporated if not run for a while. When it did start (on one side) it will have sucked the fuel into the not starting side.

Of course if it does it again tomorrow plan b.

[Nick the wanderer]

Plan b will be damp in the electrics..

[Angela Collen]

Thanks Nick for your input, fuel top quality that's why I use it and specially for classic, it's not cheap but I don't do a lot of miles and doesn't go off so good for not useing over winter, I store on main middle stand, have never used side stand, this is first time it happened but only for very short time, if it does it again  will check if electrics damp, when got time will check carbs too, thanks Nick appreciate your time

[RideWithStyles]

Was the cylinder that had taken longer to start/warm up it on the right side? (as you sit on the bike).

im guessing its a carb per cylinder and not one carb shared to both ports?

is the inside tank in good nick? Fuel filter new? Are the pipes throught good including internal? 

if so id be checking and comparing flow rates of the lines to the carbs (vacuum / pressure test) of the peacock/ pump etc first then what comes out. Then test the other components afterwards in the system including the carb like nick said.

[Angela Collen]

Hi RWS, yes the delayed cylinder on right side,has carb per cylinder and the tank is very clean, new fuel filter, and two new pipes, carbs cleaned, so will try the vacum/pressure test and go from there, its first time it's happened and maybe because i've not ran it in a month as very wet here, maybe electrics damp as Ian said, the shed is in the shade so gets damp, will have a good look at both, I have re sprayed parts where electrics run, maybe need to see if all in order too, the aspen fuel I use has no ethanol so fuel not problem causing water deposits, its an old bike that needs regular love, so will start at what you've both said and try and run it even in shed as aspen gives off no fumes ,to keep it going, when second cylinder came in 15 seconds later it ran lovely, no problems idling at stops, thanks for your time

[RideWithStyles]

Ok thanks that lessens the possibilities -now im Not say exactly these but worth considering.

If oil is thinner coated on right side as its banked over on the left creates slightly more friction on start up.

have all the carbs been balanced? Maybe the right one is just a touch leaner?

maybe the is abit of a drop leak or crude in the carb so it starts off dryer.

Id discount plugs ignition when cold start the bike but 5-10 secs after zturn off and check the plugs, are they both the same colour node burn pattern? If not clean plugs, swap them over and try again 

 

 

 

[Angela Collen]

Thanks RWS, yes plugs was something i was also going to check, good to tick that off list first, also will check petcock clean and new lines in correctly and flowing right, another job over winter is check carbs balanced on both sides, they may need regular checking on this old bike, had done at beginning of year and ran great, as i say only just started so now laid up for winter will go through the jobs, thanks for giving me headstart on where to look, appreciate your time 

[Mississippi Bullfrog]

I would not be worrying about it. It's an older bike, it hasn't been ridden for a while, it has carbs, the weather recently has been very wet and cold - it's not unusual for them to fire up and have a lazy cylinder for a bit. Probably nothing more than a damp or oily plug.

 

Use it more often. You'll probably find it sorts itself out.

[Angela Collen]

Thanks MB, good advice about using it more often, and not going to do my head in about it, but when get the time will check my work I've done over spring/summer to see all correct, and nothing needs re balancing alittle,  thanks for all posts, hope you have good evening

[onesea]

My suggestion if its in a shed then don't cover.

 

The air cold it gets damp, on a good day without a cover it will dry out.   With a cover it will dry out less.

 

Can you add ventilation to shed reduce damp?

 

Experience from boats and winter, 2 ways to stop damp heating and dehumidification or lots ventilation.

[Angela Collen]

Thank you Onesea, yes I can open small window on shed for ventilation,  good advice on cover, will try it both ways to see which works best, on good days I do get bike out and air and run it to cut down on damp, as well as dry any damp parts, eg brake disks, this is my first year back with bikes, so learning it all over again, as I go, but great thanks for everyone on forum that's took the time to help me over the past year, it's much appreciated and I have learned so much, your all legends and thank you for your experience its been invaluable!!

[Angela Collen]

Update, as weather good today got out for little ride, started both sides straight away, so hoping it was just damp, no problems on ride, so will get out when weather good to keep it going

[bonio]

I would take that as good news