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Starting on 3 cylinders from cold

Posted: Thu Apr 11, 2013 8:42 pm
by cbr400rrn
Can anyone give me any advice as to what the problem could be as ive put new plugs in, new battery, changed the HT leads, cleaned the carbs which were clean anyway and still wil only start up on number 2,3 and 4 cylinders from cold. No problem starting the bike when the engine is warm, it only happens from cold.
Thanks,
Karl.

Re: Starting on 3 cylinders from cold

Posted: Thu Apr 11, 2013 8:46 pm
by johnnie5
fuel
spark
compression

have you checked that you have spark there

checked for compression

checked valve clearances

Re: Starting on 3 cylinders from cold

Posted: Thu Apr 11, 2013 8:49 pm
by Davez29
possible duff coil or even dampness. You tested your new ht cables?

Re: Starting on 3 cylinders from cold

Posted: Fri Apr 12, 2013 8:55 pm
by cbr400rrn
Not tested the new cables yet but if it was the coil or HT lead would they not do it all the time and not just when cold?

Re: Starting on 3 cylinders from cold

Posted: Fri Apr 12, 2013 10:50 pm
by Davez29
possibly, thats why I mentioned dampness. there was a while ago when we had all that rain for ages my bike was constantly damp and for a short while it did only start on three. within minutes it was chugging along on four. my remedy was to go around everything electrical with a contact cleaner and then spray damp start over plugs etc. been fine since. I mention your leads because it appears to be doing it now and i know you just changed them so worth a look.

Re: Starting on 3 cylinders from cold

Posted: Sat Apr 13, 2013 9:58 pm
by cbr400rrn
Will give that a go, i changed the leads as it was doing it before and thought well ive got nothing to lose and was told that could be one of the causes so changed them and the plugs but no difference. Bugger :(
No1 cylinder does chime in if you rev the bike slightly when cold then will tick over normally if this helps.

Re: Starting on 3 cylinders from cold

Posted: Mon Apr 15, 2013 9:25 pm
by cbr400rrn
Well i had a look today and started the bike up and the Ht lead is good as there is definitely a spark at the plug so now i am puzzled, theres fuel and a spark so light yer bastid :x

Re: Starting on 3 cylinders from cold

Posted: Mon Apr 15, 2013 9:35 pm
by The Novice
swap the spark plugs over and see if its a duff plug.

edit - whoops just noticed youve already tried it. mine starts on three when i havent used it for a while, i just give it a little rev and they all end up singing in the end when its warmed up.