float levels k6 wont fire 1+2 choke side

[davepainter]

hi my 1976 k6 is running k+ns with basically drag pipes,engine rebuilt points set up good ridden 160 miles but 4-5 times after ride it will only fire on 3 and 4 standard jets good 105s tried 110s flooded need help what is RIGHT gap to set up correct contact with needle jet?
did plug chop at 60 correct colour
on 3rd set of plugs.
thanks dave

[Bryanj]

Is this a UK bike or a US import as all UK bikes were K2's until the K7

[davepainter]

Hi Bryan, checked logbook states date of first registration 01-08-1978?
registration number fec 154t
theres a website -hc honda 750 choppers - it has a year chart for production by engine numbers
my engine number is cb7501096714
this chart states this engine is a 1976 k6?
as my honda is a all out chop maybe its an earlier (76) import or likely doner engine?
frame number cb750f-1039713?
  REFerance misfire cylinders 1+2 or no spark at all i,ve just recieved 4 pattern inlet rubbers -still to fit- an old one split
just as well i ordered 4 set as pattern ones are 3mm shorter.david silver
aAs i mentioned i,m on my third set of plugs ngk d8ea, when i fitted the first two sets the bike IMMEDIATLY fired up on all 4pots and ran great but
next time i went to use bike she only fired on 3+4?
yesterday 07-09-2011 i fitted new plugs and immediatly she only fired on 3+4 - took plugs out 1+2 they were wet with petrol so its getting in?
maybe i need to see if new plugs 1+2 fire spark when out of head.just onplug leads.
 being a bit paranoid(but i wont go into politics) i,m also going to do an oil filter change as -By now there must be a bit of unburnt petrol down the bores
not good especially in a rebuilt engine. i will post again when i,ve checked plugs out of head spark firing. Previous times when bike started only on 3+4 i checked 1+2 plugs and they were flooded in petrol?
 

[mick]

Hi Dave its sounds more electrical than fuel?, have you checked all your wiring for points etc? i think float height is 26mm , cheers Mick.

[Bryanj]

The Honda choppers site is very accurate for US models but takes no account of the fact that Honda were still producing K2's for the UK. The 500 is even more complex.

The K1-K6 supplement i have quotes the float level at 26mm and you measure this with the carb horizontal so the float "Tang" is just resting on the sprung loaded needle without compressing the pin.

Hope this helps!

One other possibility is that if the battery is weak and the charging system not up to scratch the spark reduces in intensity and the flugs foul. If you have access to one of the old style champion media blast plug cleaners you can usually make them work again but they are a bit rare now

[hairygit]

Personally I feel it's unlikely to be electrical, as if it were, you would have problems with 1+4 OR 2+3, as these cylinders share common points and coils. So fuel is probably the area to be looking at. Is it a K6 tank and tap setup? If it is, you'll have a single fuel line from the tap, going to a T piece which has 2 pipes coming from it, one feeding carbs 1+2, the other feeding 3+4. Are you sure the plugs are wet with petrol and not oil? Use a bit of clean white rag to wipe some of the wetness onto, if it's black it could be oil, (some pattern part valve stem seals are absolute crap! ) if it was just petrol it should evaporate away in the sun quite easily

[davepainter]

To bryan mick hairygit cheers imfo-very usefull,
i,did take 1+2 plugs out of head,an hour ago and started up, looked like GOOD spark to me,
REF battery its recently been charged OK.
REF oil or petrol,since putting new 3rd set of plugs in yesterday and only starting bike twice for less than 3 minutes it immediatly only fired on 3+4?? rrrrrr
points to float height? i,ll try again tomorrow! thanks details 26mm.
a mate at work told me this today-26mm-he was right! he,s got a late model cb650 reckons float heights a bit critical.
REF valve stem seals thats scary?/ not suprised after recieving pattern inlet rubbers-david silver/ not there fault its gen honda from now on pricy yerr!
I,ve read other carb-running faults on probs page massive usefull thanks guys.
Its double piss of because when she does run on all four plugs she,s great-fek me it even ticks over at 1000 revs WITH almost no camchain slack rattle bang. MIND you if taking 750 carbs off becomes an olympic sport i,m a contender!!
i,ve even taken the plugs out after a good 30-40 mile ride and they look like the ones in the haynes manual showing perfect.
 AH yes when i took plugs out today after trying to run
No sign of oil some clear wetness-petrol on plugs 1+2 ,i,ll post when i,ve set float heights cheers DAVE.

[Bryanj]

Some parts you are stuck with pattern, like those inlet rubbers mate---Honda don't make them anymore!

[davepainter]

Still no go, yesterday Sunday i fitted the new carb to head inlet rubbers, and set the float levels to 26mm,
bit gutted still only firing on 3+4? 
i think its got to the stage of putting the bike into a local specialist ex honda centre mechanic based in fareham near portsmouth.
unless its electrics or an engine-valve-piston-fault there is,nt much more i can do
i,ve read other posts and guys have even got another set of carbs.
i,ll post again if i get this sorted out cheers dave.
any ideas on a postcard!

[hairygit]

There is one more serious thing that could be wrong, and I've only seen it twice in 30 years of playing with sohc 750s, snapped camshaft, caused by incorrect re assemly of the cam carriers, it happened on a mates rat bike, using cam carriers from different bikes, cylinders 3+4 died, so he rode it 175 miles home on 2 cylinders ( But I certainly hope that isn't your problem!) You can eliminate this possibility doing a compression test on the duff cylinders, or possibly removing the tappet covers and running the engine, oil WONT spray out if the cam is broken. If oil sprays out, the cam is still in one piece, so see if someone will lend you a compression tester and check all 4 cylinders, that will give a good idea of the state of the valves (silly question, you have checked the valve clearances? because if theyre too tight the valves wont close properly ) Still think it will not be an electrical fault though!

[Bryanj]

have you fitted new plug caps and trimmed the ht leads?

[davepainter]

Wish i hadnt looked mate, just checked tappet covers off YOUR right tappets 1+2 not even moving when bike started 3+4 as they should
its not looking good i,d say i geuss its cam cover off lucky in my case its achop i,ve got 6 inches above head to work on.
i suppose its check the damage time.
Unless i,m lucky and it is just the valve clearances.
thanks for at least finding the problem, so thats 3 times in 30 years. Still at least i know the carbs were OK???
WAY TO GO.

[hairygit]

What a bummer, I SOOOO wanted to be wrong on that point As you say, at least you can get the rocker box off in the frame and assess the possible damage.Do the tappets feel slack when you try to lift them? just a thought in case the locknuts have worked loose and slacked the adjustment right off, although I do think it rather unlikely   The only good thing is you are on this forum, so somebody may have a cam at a sensible price available

[Bryanj]

Cam with corrosion i have, cam tower maybe, rockers don't think so. PM me if you want me to look

[davepainter]

<a href="http://s839.photobucket.com/albums/zz320/davehawk/?action=view&amp;current=scan0002.jpg" target="_blank"><img src="http://i839.photobucket.com/albums/zz320/davehawk/scan0002.jpg" border="0" alt="pre rebuild">[/url]
 picture of bike before engine rebuild,might explain why she went like she did ?

Dave: you need to use the {img} button to post pics like this and then just use the url of the picture. I have modified your post to show how: (used curly brackets to stop the forum software from showing it as a picture!)

{img}http://i839.photobucket.com/albums/zz320/davehawk/scan0002.jpg{/img}