POINTS TIMING CB500/4

[Bryanj]

What model 550 is it as i have all the genuine books

[Oldbuthopeful]

It's a 550 K3 which, incidentally, I haven't yet managed to idle at anything below about 2500 without running rough
and then cutting out   -   and the slow-running jets are clear !   Any other suggestions please ?

[z1100r]

 Its running lean..your pipes are very blue. The carbs are a bit fiddly on a K3 to get the slow running right. You need to take the carbs off and start again. I'll assume you can do needles (needles may be too low) and main jet, so for slow running:-

 1) Remove float bowls
 2) Pull out slow running  jets with a firm twist and pull with a good set of pliers. Use small new pliers with good teeth, its better to mark the outside than to crush the jet with too much squeeze with a big blunt pair..
 3) blow through with airline both empty hole and jet.
 4) Hold jet up to light and you must be able to see through it. Its a very small hole, you must be able to see light through them and they must all appear the same.
 5) Remove air screws carefully. There is a washer spring and oring in that hole that must be replaced in the correct order.
 6) Blow down hole with air line.
 7) shine torch at pinhole in venturi and look down screw hole to see light. You must be able to see light.
 
 Finally, and I know they say dont do this, but if you spot a blockage in a jet you need some of these
http://www.ebay.co.uk/itm/20-Pc-Micro-HSS-Drill-Bit-Set-0-3mm-to1-6mm-Mini-V0930-/360354126518?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item53e6c79ab6

Find the right drill by trying them in a good jet then gently twist it through the blocked one - by hand. Usually its just dry hardened varnish you are removing and it comes out as powder, you wont remove any brass.

[K2-K6]

The comment about a waste buying the Boyer:- I don't think that's the case if it's what you really want as those systems have clearly been contructed by people that know what they are doing.

It's more that the standard kit is a really good design in the first place and it comes pretty close to the performance of electronic for a standard road engine.

Ths assumption if something is not running correctly just because it has an old type setup is very often incorrect and the NEW system is fitted in the hope of curing something that may have been caused elsewhere.

Oddly though, a lean running engine at lower speeds (550K3 tickover)  is one area that in theory the electronic system probably will hold more of it's expected design advantages if the coils are feeling able. So you may get to feel you've got good value if you get the carbs all clear/well adjusted.

[Oldbuthopeful]

Thanks z1100r for replying at such length.  I'm afraid the blued pipes are a red herring, because they came as part of the deal
when I bought the boxes of bits from the PO  -  and they've now been replaced by a 4-into-2 system which gives the bike a
much better balanced look.   So...........given that I carefully removed the slow running jets and drilled them out before I sent
the carbs away for refurb, would altering the needle height as you suggest still improve the slow running ?  And something that
bugs me every time I replace the carbs after a fiddle   --     can you please advise whether I really need to go to all the trouble
of replacing the rubbers just for a test start-up or will leaving them off in the short term not make any difference ?  It would be
music to my ears to hear you say it didn't matter either way !!!
Whilst you're on my wavelength z1100r, could I ask what your take is on float height ?   BryanJ will hopefully be able to
throw some light on the subject, but it's always useful to get another opinion.
Thanks also to K2-K6 for your comments.  If carrying out these carb adjustments results in a smoother-running motor, then the
Boyer can stay.  But if there's no improvement, I'll be strongly tempted to put the original kit back on, using new points and condensers
and see where we go from there.   Thanks again for the input.

[Bryanj]

550K3 float height 14.5mm and the pilot jets need the cross holes super clean as well as the main hole.

There was also a bulletin from Honda dated 01-09-77 saying that some K3's had the needle clip in the wrong position causing blueing of the original pipes----should be middle notch but was found to be second from top

[Oldbuthopeful]

Thanks BryanJ  -  only just picked up your post.

My 550K was first registered July '78 so I would hope any needle setting problems would have been overcome by then,
but when I get the carbs off I'll check to make sure.

Your float height comments were very welcome as, by chance, mine have been set at 14mm !

Thanks again for the help.

[Paull]

I have boyer on my 550 chop and it runs like a scolded cat, I will run out of balls before the bike does.
My Mate said, when I went past him at 80 I mean 70, it sounded like he had a cat stuck in his back wheel and then this red bullet screamed past.
Starts first push of the button. 
Paul

[z1100r]

 Have you sorted it yet...?? Is it purring away like a little sewing machine again...??

  I took my 500 out the other day. I was surprised that it took me 3 or 4 miles to get used to it. Been using using my Thunderace as dailly transport I guess, so going back to the apehangers and upright position seemed alien for 2 or 3 miles. Soon got used to it again and started enjoying it. Got to keep riding it, I dont want my nice spangly new carbs gumming up.

 My float heights are 14mm aswell...I always set them on the rich end of what the book says.  14.5 +or- 1mm.
 My needles are the 50's not 49's and are in the middle groove. The 50's i think are thinner at the top (richer) for initial pickup, but the same as the 49's after that.

 My bike is a bit weird as its a 500 chassis, with 550K3 engine bored to 601cc using +0.050 GPZ305 pistons with K3 carbs on modified 500 airbox (The bottom of the box is cut out for extra air). Had to buy Longer 550 rubbers from states. Main jets are 112.5  (std are 90's). Head and manifolds are gasflowed and valves are bigger. With the race cam it used to rev to 12,500rpm but with a stock cam its only 10,000 but with more grunt.

 Even with all those mods its on stock points ignition/timing (std cam) with only main jet changes to the carbs. Primary jets, slides, needles float heights etc are all totally stock and it runs perfect.

 Dont forget to balance your carbs.