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Messages - paulbaker1954

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1
CB500/550 / Re: 30 years of storage later
« on: July 17, 2019, 02:25:11 PM »
Hey Ken, I bet the looms a bit of a "Rats Nest" LOL

May be a fairly easy resto as you had done it once before though.

Are you going to try the DK magic sales pitch such as "engine turns over, has compresssion and we have had it firing on a few squirts of starter fluid" . Seriously though be interesting to see if she still runs !!

2
CB500/550 / Re: low float level symptoms
« on: July 12, 2019, 10:57:58 PM »
By drop out,  I mean a non fire for one or more cycles of that cylinder.

To get a backfire of any size in the exhaust pipe you have to have some proportion of fuel left unburnt.  Depending how rich carbs are set up that can vary,  but add a little oxygen from an exhaust leak to it, making it more volatile,  and you get that characteristic pop.  That can be normal with just the exhaust leak as a fault,  without that the rich mixture can just pass right through and give you a petrol heavy smell at exit without popping.

Your pulling away cleanly problem though suggests you've got at least one cylinder not firing cleanly while running at lower levels of carb range. This would also have the potential to give those exhaust backfire results.

So linking the two trait together suggests you've got a no fire result some of the time on one of the cylinders while on idle circuit.

The question is,  what is causing that? 

The check of HT leads may show you some leakage which can do this as it can give sporadic sparks. 

The other is of course carbs,  hence the question of what response you get by turning each screw individually to see if you are getting a linear response from each carb idle circuit in isolation.

Thanks that’s great input, I have managed to get rid of the backfire by adjusting the idle screws, HT leads are pretty much brand new as they were all replaced last year when I fitted the full Boyer kit so am still suspecting an idle circuit problem. That said I did a full ultrasonic clean of the carbs last year and all the idle circuits were fine then.

It’s a lot better now having adjusted the idle screws and have chucked some redex in the tank so think will just run it a while and see if things settle down

3
CB500/550 / Re: low float level symptoms
« on: July 12, 2019, 07:22:58 AM »
Thanks K2-K6 thats very helpful.

Usually your first suspect is air leak on the exhaust side of combustion chamber that causes any popping in down pipe / silencer.  Or drop out from firing cylinder cleanly so you get occasional unburnt mixture going out of cylinder.

Just a thought about uneven running,  and your initial problem of pulling away.  How confident are you of HT leads? Have you tried running it in the dark and looking for escaped sparks around the leads?

Could you explain what you mean by drop out from firing cylinder cleanly so you get occasional unburnt mixture going out of cylinder.

4
CB500/550 / Re: low float level symptoms
« on: July 10, 2019, 01:22:27 PM »
HAVE YOU CHECKED FOR AIR LEAKS ON THE INLET SIDE..? ALSO CHECK THE COMPRESSION, CHECK THE IGNITION TIMING/POINTS GAP AND REPLACE THE PLUGS, CHECK THE AIR FILTER ISN'T BLOCKED. IF YOU DO ALL THAT AND STILL HAVE AN ISSUE YOU CAN START TO GO THROUGH THE CARBURETOR SETTINGS.

Done all of the above !!!

5
CB500/550 / Re: low float level symptoms
« on: July 10, 2019, 09:54:46 AM »
Thanks K2-K6 thats very helpful.

Its also odd as since the rebuild I am getting an odd afterfire (popping in exhausts rather than a  true backfire) in cyls 1 and 2 that happens only every minute or so (ie not on every firing stroke) which goes away when I wind the idle screws out a bit.

Not sure

6
CB500/550 / Re: low float level symptoms
« on: July 10, 2019, 08:54:15 AM »
Paul, not sure I understand your issue, isn't it rather too rich mix on low rpm symptom? The same I'm facing?

When you try to engage choke that should make mix richer (at least partially) it helps of make it worse?
If it helps, your mix is too lean, if it is worse, it is too rich... I'm not expert but this is my exprience

In my case I have clearly too rich mix and still did not fixed that (you know my thread well :) )

That may well be the case but  I just was asking what the symptoms of low float levels are that's all

7
CB500/550 / low float level symptoms
« on: July 10, 2019, 08:11:43 AM »
Hi,
My bike has been not quite right since last rebuild for head gasket. I think it may be down to float levels but just wondered what the symptoms pf low float levels are.

My issue is pulling away from standstill I have to ramp up the revs or she tries to stall. Hill starts are even more of a challenge requiring me to gun it whilst slipping the clutch. I am confident pilots are clear as they are new and I also checked recently all the pilot air channels but I think float levels on 3 and 4 may be a bit low.

8
CB500/550 / Re: 550K1 - carb questions (022A)
« on: June 25, 2019, 10:50:26 PM »
Where is SK? just trying to see what your location is.

Ha Ha not near Stockport then Ken :)

It did cross my mind Paul, thought I could pop over and sort the carbs out for him.

Hey nice run to Bratislava

9
CB500/550 / Re: 550K1 - carb questions (022A)
« on: June 25, 2019, 12:43:21 PM »
Where is SK? just trying to see what your location is.

Ha Ha not near Stockport then Ken :)

10
Agree with other posters 500/550 is great for town use country amblee etc whereas 750 probably which is just heavier better for longer trips etc. I love my 500 which I bought as a DK import with a fully seized engine but excellent chrome and very few bits missing. I paid £1,600 and then about another £1,700 on the rebuild which included a full engine strip with new pistons, seals etc etc and also a full set of repro 4-4 exhausts from CMSNL which alone we around £800 but well worth it to replace the 2-1 pipes it came with.

I ended up with a bike that looks good but is not a concourse restoration but I like it like that (a bike that age looks OK with a few scars!!!)

If you can find an earlier model K0 ideally or K1 as they will (maybe) be worth more. Also depends on how much restoration work you want to do and of course how competent you are.

There are a few always on ebay but some are really stupid money but there are some decent ones come up from time to time. I would expect to pay no more than £6K - £7K for a decent example but others may disagree with me here

you may have seen this but this is currently on Ebay and would be a good easy project.

https://www.ebay.co.uk/itm/honda-cb500-four-1972-k1-11k-miles/333246173961?hash=item4d97051309:g:c84AAOSw0eNdEJPK

11
CB500/550 / Re: 550K1 - carb questions (022A)
« on: June 25, 2019, 08:53:18 AM »
Small update, I'm just back from garage.

I did start the bike ususal way (w/o choke), after warm-up I was checking ingition, found stripped screw on 1-4 points  >:(, after fixing it, static settings and settings with strobe light I went for test ride. Bike generally pulls good, was able to rech pretty 90mph (reading on tacho gauge).
Mix screw set to 1 3/4 turns out (looked to me the best) on all, did not manage to make my RPM meter meauring reliably so did not played with each carb separately.

Another observation linked to carbs - after engine fully warmed-up, when idling stable for several seconds, I tried to quickly twist the trottle and engine dies! Is that normal? I manage to reproduce anytime... slower twisting is OK...

Note: after spending quite some time with points ( >:( >:( >:() where one is obviously replica, and still having strobe flashing irregularly, fire mark moving left-right, I'm strongly thinking about Dyna S. I installed it to my friend recently and it was really perfect...uncomparable with points. New points set cost ~100 USD, new Dyna S about 160..

I don't have any experience with Dyna ignition but I put the full Boyer kit on mine including the Micro Coils and I would highly recommend this set up. Bike just runs better all round, starts easier  and no more points maintenance !!

 Also very easy to fit and their tech support is excellent.

http://www.boyerbransden.com/microdigitalmicropower.html

You need KIT00289 and when I bought was £218

ALso see my post on how I installed the Boyer coils using the standard Honda brackets (makes for a very neat installation)

http://www.sohc.co.uk/index.php/topic,14509.msg117905.html#msg117905

12
CB500/550 / Re: 550K1 - carb questions (022A)
« on: June 24, 2019, 11:30:22 AM »
OK, now it is clear.
So I still have some issue to fix  :'(

One thing worth adding is that in fact the original Honda manual states that you should warm the engine up before riding. See below from manual

After the engine has been warmed up, the motorcycle is ready for riding.

13
CB500/550 / Re: 550K1 - carb questions (022A)
« on: June 24, 2019, 10:59:43 AM »

Yes on the 550 there is no throttle speed increase mechanism like you normally find on other carbs.

I normally use choke open to start and once running close chokes to about half way whilst it warms up. I do NOT need to keep the throttle open though whilst warming up so there is something not right with your setup. Moving the clip will not (I don't think) help as the needle position only starts to have effect at higher revs. That said I run mine in the middle position so you may want to change them ans see if it has any impact.

"I normally use choke open to start and once running close chokes to about half way whilst it warms up" - do I understand you start engine like me, e.g. w/o choke use (= choke open) and then you use it halfway? Or wise versa, meaning you engage choke fully (= flaps are fully closed, so restricting air and making mix richer)? Sorry for such question, I'm not native english speaker  :D

I normally start with choke fully engaged (ie flaps fully closed (lever in fully up position) and then lower to around halfway once running.

As these bikes dont have a device to increase throttle with choke movement they rely on you to do that !!!

14
CB500/550 / Re: 550K1 - carb questions (022A)
« on: June 24, 2019, 10:28:46 AM »
Unsure of choke application on this carb set,  don't think it lifts throttles as well as making richer?

K7 definitely lifts throttles with choke application,  manual allows nearly 3000rpm for running on choke so it's quite a bit of throttle applied when set. So fundamentally different from this one in discussion.

All the symptoms seem to agree with your feeling of running rich. The exhaust would smell of fuel too if that's the case.

You say that needle clips are in fourth position,  is that 4 from top of needle or 4 up from bottom position?

Suggestion if not like this,  put needle clips in fourth slot from bottom of needle (lowers needle to make leaner) then turn idle air screws out 1/2 turn from where they are.

You will need to use throttle while it warms up on this I believe.

Yes on the 550 there is no throttle speed increase mechanism like you normally find on other carbs.

I normally use choke open to start and once running close chokes to about half way whilst it warms up. I do NOT need to keep the throttle open though whilst warming up so there is something not right with your setup. Moving the clip will not (I don't think) help as the needle position only starts to have effect at higher revs. That said I run mine in the middle position so you may want to change them ans see if it has any impact.

15
CB500/550 / Re: 550K1 - carb questions (022A)
« on: June 24, 2019, 08:58:53 AM »
I am not sure what your real problem is here, you say bike wont start on choke but you are obviously able to start it, so is the issue that it is harder to start than you would expect only from cold.

I am assuming the chokes are operating properly as Gerben has rebuilt the carbs and I am also assuming the pilot air circuits are clear and the pilot jets are clear.

Are you using the correct starting procedure, below is what the original Honda owners manual recommends

COLD ENGINE STARTING
PROCEDURE
1) Turn the fuel tank valve to the "ON" position.
2) Insert the key into the main switch and turn to the "ON" position. At this time, observe the GREEN neutral indicator lamp on the lamp cluster. The lamp will be lighted when the transmission is in the neutral position. Also at this time the RED oil pressure warning lamp should be lighted. If the lamp fails to come on, the connection should be checked for an open circuit and the bulb checked and replaced if burned out.
3) Make sure that handle grip ignition switch is in the "ON" position.
4) Position the choke lever to the full closed position.
5) Twist the throttle grip inward slightly and depress the starter button. If the engine does not start within 5 seconds, release the starter button and allow the starter motor to rest for approximately 10 seconds before pressing the starter button again. If the engine does not start readily with the electric starter, to prevent excess battery discharge, use the kick starter pedal to start the engine. If the engine fails to start after several repeated attempts, turn off the main switch and lower the choke lever to the full open position, twist the throttle grip inward fully and crank the engine using either the electric starter or the kick starter pedal. This is then followed by turning the main switch to the "ON" position and following the starting procedure out-lined in steps 1 through 5, however, at this time the use of the choke is not necessary.
6) After the engine starts, operate at approximately 2,000 rpm until the engine will properly respond to the throttle with the choke open.

You also say that when warm it runs and idles well which would seem to indicate that the idle circuits and pilot jets etc in the carbs are all OK.

My 500 was never been a brilliant starter from cold and always needed a few cranks and throttle opening to get going. This has got better since moving over to a Boyer Ignition system using the Boyer Micro Coils. This led me to believe my starting issue was more down to maybe old weak coils rather than a carburation problem.

Here is my recommendation

1) Make sure there are no air leaks at the carb to head rubber joints
2) Are you sure you dont have a restriction in the fuel lines ( I had a strange problem with my old petcock that was strangling the fuel flow). I found this because if i turned the fuel on and then left the bike for 5 minutes this gave time to fill the float bowls and starting was much easier. Have you tried just  directly connecting an external auxiliary fuel tank to eliminate any such issues
3) May be worth changing points and condensors
4) Try another set of coils if you are using the original ones
5) You said you used a 38 pilot jet but I thought the right one was 40 (that said I have 627 carbs)
6) Make sure this is not an ignition problem rather than a carb problem




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