Strange fault

[flc]

I took my bike for its mot today( it flew thro
The fault is that from cold it will start first kick, but if you dont catch it properly and rev it a bit till its warmish.
and it stalls then im in for a sweaty 50 kick marathon even bumping didnt get it to go...
any ideas?
ta flc.

[matthewmosse]

Checked plugs, leads? sounds either like it's flooding or has a carb issue? plugs should give a clue what's going on.

[Bryanj]

Low battery charge/bad spark

[flc]

I had an hour today.
 so had a nose,
 id left battery charging overnight.
still no joy, so pulled plugs and all are dry? ive since wound out the pilot screws a full turn, and she fired up?
not sure if i stumbled on the fault or was on my 50th kick wil see tommorow once its had time to cool,
i did notice the left hand conecting manifold hose thing?? is split and the previous bodger/owner has used normal car jubilee clips. i have another set so looks like its carbs off time (my favorite job). thanks for your help so far folks.

[matthewmosse]

Sounds like an air leak is your culprit then, dry plugs and a split manifold - cause and effect, too much air getting in, lean mixture would make starting difficult. I'd not worry overly about the jubilee clips but the split manifold will need remedying, new ones can be a problem to source but do come up used on ebay. A bodge repair using cloth and gaskett goo can be effective as a  bodge to keep things running.

[Bryanj]

500/550 up to and including 76

Head to carb rubbers still available from Honda
Airbox to carb rubbers available pattern from Dave Silver

Ordinary jubilee clips are too wide and knacker the rubbers

[flc]

Well, its been a while since i was able to play in my shed, and its been hard.. i found that although most of the carb rubbers did have some visible splitting they still held pressure (sticking them in my palms and sucking ) !!! not exactly a honda approved technique but it did show that maybe that wasn't the fault.
This was confirmed when i ordered a nos rubber (i found on ebay) and it was the same when subjected to the suck test.
Leaving me stumped and going on mathewmosse post, i had another look at the carbs
 blowing air through pipes and a good look over i found nothing conclusive, the float levels were all the same at 17mm looking like who ever set them knew what they were doing.
but i then looked for my haynes and as i suspected this book only covers the earlier type carbs?
and after searching through this site i find that the correct setting for k type carbs is 14.5mm mmmm a good 2.5mm away.
I must say that 20 years as a fitter/mechanic on all types of engine i have never cured a problem by adjusting the float level. but it was the only thing left. so back on today, tried gas in them before fitting (been there before) and on the third kick a lovely burst settling down to an even tick over. heaven....
 But now leaves me thinking fitting larger pilots, was a plaster over the real fault(and i lost one of the origionals ). only a good run out and a plug chop will tell me what i need to know.
i will post the result soon as the snow gives up ta FLC..

[flc]

Still no joy,ok through the rev range but still got the starting problem, ive checked this over a dozen times plugs/ tapets/points etc.runs .  plugs still seamed dry, so got to thinking carbs again, are they off some strange clean air model or cb 650, i then came across this
http://en.allexperts.com/q/Motorcycle-Repair-837/1978-CB550-K-carburetor.htm
hmm 12.5mm float height.... carbs off again and re set floats to what i think is 12- 13mm (has anyone got any pics of these carbs in bits? or info on float height setting)
it start firing on the first few kicks then started, im not sure if its cured it or not, i have thought i had fixed it before.
i will know more after a run out on it...
more later........ flc.

[Bryanj]

The only info on the K3 carbs is a crapy Honda supplement to the 500/550 workshop manual with not very good dark pictures.

I have the complete manual with all the supplements scanned onto a CD you can have for postage cost + maybe a beer voucher

[flc]

bryanj you have a pm..
Well the bike now starts loads beter and runs strong until warm,
then a bit spluttery at small throttle openings.
making me suspect that the larger pilots are now too large(corresponding with sootyish plugs) and were all along hidding the real fault of too large float height settings. Does anyone have a spare standard push in pilot jet they would sell? ( i lost one of mine when i changed them )
more later FLC.

[Bryanj]

Now you are being a pain!! I know i have 3 about as i had to buy a set of 4 from canada when one would not clean out on a mates bike, so i suppose i have to turn my desk upside down to find 'em

[mickwinf]

hi all, glad its not just me has these carb problems, my pilot jets are completely blocked,i cant even push stiff wire through.Are these available to buy new? regards, Mick

[andy_c101]

I think the company that stocks cb sohc carb kits & jets etc is:-
Sirius Consolidated Inc. in Canada.
http://www.siriusconinc.com

They are sometimes on Ebay too.

Andy C

[flc]

I got my larger pilots from them, about 3 weeks to get here due to customs etc, they did warn me when i purchased a good company to deal with.

[flc]

Now you are being a pain!! I know i have 3 about as i had to buy a set of 4 from canada when one would not clean out on a mates bike, so i suppose i have to turn my desk upside down to find 'em

i know.... i had one in my pocket whilst hoovering my car on our gravel drive, when i checked my pocket it was gone so its either somewhere in the gravel or up the vacuum. i spent a while groveling in the dirt but no joy. I you have one that would be ace .
Ta FLC.