Sooty Plugs !Sooty Plugs !Hi Guys,
Just getting my CB77 back on the road with some 'gentle' recommissioning and have run into an issue - can you help?! So, points set, valve clearances set, new jets and needles (from Kevin at Scrambler Cycle), needle clip set on 2nd from bottom notch, floats checked and height set as per the recommendations here... Starts really easily, idles well and (on the stand with no load) revs cleanly, however when in gear and ridden it bogs somewhere around 1/4 throttle and up and won't pull (struggles to get over 30mph). The plugs are very black and sooty but dry. A condenser problem? Any help is appreciated Dave Obviously running rich, is your air filter elements ok, have you got the correct size jets in, were the carbs stripped and cleaned,
Honda CB77 CARB SPEC- 26MM BORE SHOULD BE ON SIDE OF CARB MAIN JET- 135 SLOW JET-42 PILOT SCREW TURNS OUT 11/2 PLUS OR MINUS 1/2 TURN (that's not eleven and half but one and half turns out do not force the screw in on the stop) NEEDLE CLIP POSS-3 THROTTLE VALVE CUT AWAY-2.0mm FLOAT HIGHT-22.5mm
Re: Sooty Plugs !Please add your location. ........................lm
Hi All,
Thanks for the replies... LM - I am in the UK. SBMH/Rrietman - I have (re) checked those things a couple of times (Carb settings etc - they are all as per standard and the slides are in the correct sides, and the right way round :) ) and the plugs and air filters are new. I've tried running the motor without the air filters/tubes attached but the plugs are no different only a 'lean' condition sounding backfire from the carbs every now and again which kind of led me down the path of thinking the issue may be condenser/electrical. Maybe the sooty plugs are one issue and the 'not pulling/revving' under load is another? Cheers D Have you got standard Keihin jets in your carbs or has someone fitted a Keyster kit. Often the Keyster jets are not to the same spec - even if they have the same numbers - than the originals.
Needles in the right position? Float height correct? Timing checked with strobe? G
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F I know it sounds odd but are you sure that you are running on both cylinders? I have seen bikes start up easy and happily idle on one cylinder as long as you want them to. When you try to ride them though there can be a noticeable lack in power. Touch the pipes or pull one plug wire while running, replace, and then pull the other. Careful, you can get a bit of a jolt. If it continues to run just like it was before you pulled that wire then that cylinder was doing nothing.
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