Honda-SOHC
SOHC.co.uk Forums => CB500/550 => Topic started by: barney on October 07, 2011, 09:34:35 PM
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I am at the stage of my rebuild in deciding to fit a Boyer system or not. My question is when trying to set the points, I find the correct mark for cylinders 1-4 and set the points gap, all is OK. Then when I rotate the crank for setting the 2-3 cylinders the points for 1-4 are still opening making the gap wider !!
Is this normal or should I have to rotate the points back plate to compensate ? The points cover has been set on the rebuild by lining up the scribed mark line which was put there before stopping down.
Thanks,
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I find the correct mark for cylinders 1-4 and set the points gap, all is OK. Then when I rotate the crank for setting the 2-3 cylinders the points for 1-4 are still opening making the gap wider !!
Just to make sure you did it right: you DON'T set the points gap at the mark, you set the gap when it is at it's widest (and that is certainly not at the mark). The mark is for the timing of the ignition, it's the position where the points begin to open. This timing is done after you've set the points gap. So, two different things done at two different crankpositions.
Step 1: turn the crank till gap is at it's widest and check if this gap is within specs. If necessary adjust by moving the set of breaker points.
Step 2: Check the timing of the ignition. That means point should start to open at the mark. Adjustment can be made by moving the backplate.
Check your manual.
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Just to add to the above which is correct:-
As you move the points plates to correct timing you can get small variations in the points gap depending on the accuracy of the mechanical fittings, so you may need to fiddle about for a bit to get both settings accurate.
They aren't hard to get working well though and for a non race engine they are a fairly nice setup with no really inherent limitations and generally seem to be long term reliable, so shouldn't give you any concerns in use.
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I have to agree with the above comments. I have been running mine on points since 1995 and no problems. I've had to change them a few times but not very often. I have also been surprised by how far they can sometimes go out of setting and yet the engine will still run well without apparent problem, usually when I am really overdue in replacing them.
Many years ago my friend had an electronic ignition set which was always going wrong. In the end we took it off in favour of points.
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I have the points in my 500/4 that came with it when I bought the bike, I use it for work every day, I bought it 27 years ago :D :D :D :D
I check the gaps every few years and they've never altered
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Many years ago my friend had an electronic ignition set which was always going wrong. In the end we took it off in favour of points.
So you blokes would not recommend the use of electronic ignition control on CB500/4s at all?
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I think it's just that the standard setup has no significant problems and is generally very reliable, they almost never stop from a problem in this area with just basic maintenance, so you wouldn't pinpoint this as an urgent need to replace it.
Longer term you are more likely to get issues with HT leads and plug caps that give problems in the wet/damp, this would be my first point to make sure you avoid any problems in general use especially given the age of some of these parts.
As the points run directly on the crankshaft then the switching speed is quite fast which builds in a good performance. As they don't really get to VERY high revs then you don't get into other compromises either so they generally match quite well the standard performance of the engine.
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The way I look at it is this:-
If you are doing 1,000's of miles a year (Unlikely with the age of bikes we have) it might be worth fitting electronic to save the adjusting every 3,000
If you are doing less than 1,000 a year it simply aint worth it as you will only need to adjust infrequently and any standing problems are cured with a dose of WD40----other products are available!
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Yes Bryanj, makes sense; I'd applied the POV of doing >12T miles a year ;)
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I ran my oufit with standard points for about 100,000 miles with barely any interference but the replacement set I eventually fitted gave a lot of problems and just kept going out of time or so it seemed - I'm now having doubts that it was the points as at the same time I did a swap over to a 550 k3 engine and carbs and going by reading on this forum I think the carbs were the bug bear
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I've always stuck with points, if it was good enough for Hondas racing bikes in the 60's, it's good enough for a road going bike! ;D I have even used car condensors (Lucas ones from a mini) and they have been just as reliable as (very expensive!) genuine ones, annual mileage is often 16,000 plus :) and NEVER a breakdown!
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I have given up with aftermarket electronic ignitions. I have had 3 blow. I mentioned this on the US site and ended up being accused of not knowing what I was doing by some yank arse. First to blow was a Martek on my Yoshi 460 race bike. Left it switched on for 2 hours by mistake...kaputsky.
My bike is also still on its original points and condensors from new. OK there was a sizeable gap where Boyer, and Piranha had a go at providing the sparks - but in the end the points went back on. From 75-83 it had points and they did 30,000 miles, from 83-87 it raced with electronic ignitions, from 87-95 it commuted 70 miles a day with last electronic ignition to begin with and then back on points after about a year. From early 2000 bike was left to die abandoned in an old lorry until begining 2011 when it was fully restored and is now back being used regularly again. That original 1975 points timing plate has seen some action I can tell you - and still is doing. I bought new points/condensors from DS but couldn't be arsed to fit them whilst the bike is still running great on the old ones.
I wouldn't bother with aftermarket electronics.
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I understand all of the technical advantages claimed/produced by electronic systems, but most of those are quoted as a gain from some poor points systems.
These standard points equiped Honda systems were not poor to begin with and many of the gains are marginal. What is not marginal is a failure that strands you somewhere which you just don't seem to get with the original installation given basic servicing.
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...which you just don't seem to get with the original installation given basic servicing.
Which is the general base anyway... or should be...
Points were used for decades, worked flawless, as long as they received just a little TLC... (did have VeeDubs and such)
And since the combined experience of the owners doesn't indicate any weak point there, I rather save the quids for other essentials.
Besides that EI-farkel is not the true spirit of running CB500/4s 8)
cheers!
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Oh 'eck !! Sounds as though the 170 quid I've just spent on a Boyer system for my 550four was money down the pan !
I can't comment yet on whether I think it was worthwhile because I haven't managed to get the old girl round the block
without her being reduced to a spluttering, mis-firing apology for a 'four'. In fairness, I must say the carbs are a bit suspect
as the guy who recently checked them out and fitted new Keyser refurb kits (Andy from NRP Manchester) had problems
verifying the float height. He had two conflicting sources of (written) information - one saying it should be 12.5mm and the
other giving 20mm - the latter from what he called his 'bible'. We settled for 14 and he rebuilt them at that, but after telling
him about the mis-firing and the fact that the plugs on the non-firing cyclinders are wet, he suggests trying the floats at 17mm.
So it's off with the carbs yet again. I don't mind the dismantling so much, it's putting them back and knowing that I've still got to
wrestle with the b....y rubbers that sucks.
Stop Press : I fitted new plugs yesterday before I began the carb exercise and she fired up on all four, but I've not had chance
to get her out for a run, so watch this space . The Boyer might have been worthwhile after all !
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What model 550 is it as i have all the genuine books
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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 ?
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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 (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.
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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.
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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.
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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
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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.
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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
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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.