Topic: Electronic ignition [Dave Silver] Help needed please

[hondacr]

Hi Guys

I have a CB 750 K 6 with a Dave Silvers electronic ignition fitted, I want to check if the timing is right, I have not got a stobe timing light...So I read the instruction which tells you  the set-up
"Turn the crank clockwise to the F1.4 mark then to slowly move the ignition plate anti clockwise until the LED lights up then tighten the 3 screws...so I did all that but then the instruction says to check by "turning the crank "clockwise at least one rotation & check " if the LED lights up during half rotation which it does not light up on half rotation, it only lights up on a full revolution to the F1.4 mark.. have I got it right or not ?

The bike starts up 1st time & seems to idle & run very well in the garage, but not had out on the road since doing this due to sh*t weather.
instruction sheet below

[pjlogue]

I don't know what brand the DSS ignition is.  Your best bet is to do a dynamic timing with a timing light.  You need to check the 1,4 and 2,3 timing to be sure they are both are spot on.  The DSS ignition may not have an LED for the 2,3 pick-up. 

-P.

[hondacr]

I don't know what brand the DSS ignition is.  Your best bet is to do a dynamic timing with a timing light.  You need to check the 1,4 and 2,3 timing to be sure they are both are spot on. 

The DSS ignition may not have an LED for the 2,3 pick-up. 

-P.

Thanks for the reply, I think you are right...

I have just gone through it again  ...what happens when I get the light on at F1.4 if I carry on turning the crank the light stops on until 2.3 but goes off just before the F mark at 2.3.  it is ticking over really good & sound good in the garage but i'm going to give it a run tomorrow & if it goes well then I will stop messing with it, if it isn't running well.. time for strobe timing light...

[Bodi]

There should be two coil connections - one for 1-4 and the other for 2-3. The coils fire when power is removed, ie when your test light comes on (meaning the connection in the unit from coil to ground is opened). When exactly it goes off again is not important, it should in theory be off for about half a crank turn but electronic ignitions can turn it off again after a few degrees of rotation. What the instructions mean - I think - is that when rotating the crank clockwise (direction when running) the test light should go on at the timing mark, go off somewhere after that, and not go back on until you've turned a full turn back the the mark.
What you describe is pretty good for the 1-4 timing. The 2-3 timing may be independently adjustable?

[hondacr]

There should be two coil connections - one for 1-4 and the other for 2-3. The coils fire when power is removed, ie when your test light comes on (meaning the connection in the unit from coil to ground is opened). When exactly it goes off again is not important, it should in theory be off for about half a crank turn but electronic ignitions can turn it off again after a few degrees of rotation. What the instructions mean - I think - is that when rotating the crank clockwise (direction when running) the test light should go on at the timing mark, go off somewhere after that, and not go back on until you've turned a full turn back the the mark.
What you describe is pretty good for the 1-4 timing. The 2-3 timing may be independently adjustable?

Hi Bodi

Thanks for your input, still not sure about  the 2-3 set-up, if it is at all needed with the DSS system, perhaps you only have to set up it at 1& 4...

[Bodi]

Not unusual to have no adjustment for 2-3, but it could be worth checking the timing to confirm it's correct - maybe it's slightly adjustable by shifting the plate in the locating bosses?
Best to set timing using a strobe, setting it to fire at the advance mark with RPMs high enough to be fully advanced.

[thep1pe]

I have the dss ignition fitted to my bike. You are over thinking this. Once you time it forget about points 2&3, the 1&4 2&3 are 180 degrees so timing 1&4 sorts 2&3. If it’s running and revving leave it and take it for a run. I have it for 3 years now and only set timing when I fitted it.

[hondacr]

I have the dss ignition fitted to my bike. You are over thinking this. Once you time it forget about points 2&3, the 1&4 2&3 are 180 degrees so timing 1&4 sorts 2&3. If it’s running and revving leave it and take it for a run. I have it for 3 years now and only set timing when I fitted it.

Hi Mate

Thanks !
I have sorted the timing out... took it for a run today & it initially ran fantastic but on the way home after a 30 mile run cylinder 4 packed up so I was running on 3, got home took the plug out which is a new plug & it was wet and dark I tested the spark but nothing until I cleaned it, so its obviously fouling up after a good run, I cant understand this as the mixture screw is set for the weakest fuel setting, however this has been a continuing problem for a while, so my guess is that its the carbs not the electrics, the coils are also brand new Honda Coils...the carbs are PD carbs which have been rebuilt except for the floats, so the carbs are the next thing to look at.. ....any guys are very welcome

[pjlogue]

I have not seen any electronic ignition pick up coils that are not independently adjustable (i.e. 1,4 and 2,3 able to be adjusted independently from each other) it doesn't mean there can't be a system like that but I would think the main base plate adjustment would serve for 1 pick up and then the other pick up would be adjusted by actually moving the pick up slightly with reference to the base plate. 

On the Dyna III I have, the 1,4 are attached (fixed) to the base plate and the 2,3 are screwed to the base plate with a bit of adjustment via an ark where the screws go through the pick up.  I never realized this was there until I restored my 750.  I put the strobe on the 2,3 set and low and behold the 2,3 was off by several degrees.  This is how it came from the Dyna factory. 

It is very easy to check with a inductive strobe.  Should be just as easy to adjust the 2,3 pick up as it is to do the 1,4.

-P.

[hondacr]

This photo below is the Dave Silver Elec' ignition

[PeWe]

You use stock advancer?
It has a play when you loosen the 10mm M6 nut, right?
Very important that the advancer sit in correct position before locking it with the nut. Counterclockwise position is correct, then tighten the nut. F will now line up correctly with case mark when setting it with ignition strobe lamp

If advancer sit to the clockwise position, igntion will be advanced 3-4 degrees if lined up with case mark. I have made an alternative case mark for this. I did that for correct cam timing and true TDC and "T", but have noticed it's even more important for correct ignition timing and avoid too advanced ignition which cause problems on low throttle lifts.... compensating with richer carbs that will cause blacker plugs..

I have seen that on 2 crankshafts, verified correct TDC vs case mark with pistons stop, visually without head and dial indicator.

[PeWe]

I have the dss ignition fitted to my bike. You are over thinking this. Once you time it forget about points 2&3, the 1&4 2&3 are 180 degrees so timing 1&4 sorts 2&3. If it’s running and revving leave it and take it for a run. I have it for 3 years now and only set timing when I fitted it.

Hi Mate

Thanks !
I have sorted the timing out... took it for a run today & it initially ran fantastic but on the way home after a 30 mile run cylinder 4 packed up so I was running on 3, got home took the plug out which is a new plug & it was wet and dark I tested the spark but nothing until I cleaned it, so its obviously fouling up after a good run, I cant understand this as the mixture screw is set for the weakest fuel setting, however this has been a continuing problem for a while, so my guess is that its the carbs not the electrics, the coils are also brand new Honda Coils...the carbs are PD carbs which have been rebuilt except for the floats, so the carbs are the next thing to look at.. ....any guys are very welcome

Cyl 1 and 4 use same coil and ignition output.

If 1 work but not 4, it must be the output from the coil or the HT lead and cap only. Switch 1 with 4 and see if problem follow the cable which is probably will do.
In worst case a new coil.

[hondacr]

I have the dss ignition fitted to my bike. You are over thinking this. Once you time it forget about points 2&3, the 1&4 2&3 are 180 degrees so timing 1&4 sorts 2&3. If it’s running and revving leave it and take it for a run. I have it for 3 years now and only set timing when I fitted it.

Hi Mate

Thanks !
I have sorted the timing out... took it for a run today & it initially ran fantastic but on the way home after a 30 mile run cylinder 4 packed up so I was running on 3, got home took the plug out which is a new plug & it was wet and dark I tested the spark but nothing until I cleaned it, so its obviously fouling up after a good run, I cant understand this as the mixture screw is set for the weakest fuel setting, however this has been a continuing problem for a while, so my guess is that its the carbs not the electrics, the coils are also brand new Honda Coils...the carbs are PD carbs which have been rebuilt except for the floats, so the carbs are the next thing to look at.. ....any guys are very welcome

Cyl 1 and 4 use same coil and ignition output.

If 1 work but not 4, it must be the output from the coil or the HT lead and cap only. Switch 1 with 4 and see if problem follow the cable which is probably will do.
In worst case a new coil.

The coils are Brand New [Genuine Honda] cost £230.. although cylinder 1 plug is black & a bit sooty that's the main problem is with No 4 that fouls up & eventually stops firing...
After cleaning the new plugs in 1 & 4 again today i Took it for a good 50 mile run, for the 1st 35 mile it ran fantastic like a gold watch, but then it started missing again on cylinder 4, got back home took out the plugs and again 1 & 4 black - 2 & 3 are Good ! a nice light coloured golden brown.

I am now thinking carbs for 1 & 4...but as said previously I have adjusted the air fuel screws to maximum lean, so not sure which way to go next....

[Deltarider]

Hondacr, before diving into the carbs, I'd start with a simple test. To rule out another possible cause, I'd first check the plugcaps 1+4 (and maybe 2+3 too) with a multimeter (Ohmmeter). Please inform us what resistance they have. What plugs do you run, regular or the 'R' type? Also check the plugwires, their routing and see to it they do not 'leak' to ground. If the wires happen to be the carbon core type, abandon them. I am not saying it's the cause, but I would not start with the carbs, before I've checked all aspects of the ignition, the more since the problem occurs on 1+4.

[hondacr]

Regarding the plugs I was using the DR8EA-L but just changed to 1 & 4 to D8EA as I have resistors caps on the leads obviously, it did seem a lot better today for 30 odd miles then it started missing again but not as bad as before,I was thinking of going to a D7EA [hotter range] just to see if it makes a difference. I am not a expert in this field by a long way...but I can manage an oil change.

Also the leads & coils were fitted brand new not long ago & at first the bike ran great this problem has come on recently & it still runs great when I clean 1 & 4 plugs for a good few miles as mentioned but its just a pain having to faff about with it continuously.
I am not sure what the core of the leads are. if I cat sort it before next season I will book it in at a guy who is a bit hot with the Honda sohc .

[Deltarider]

Resistor plugs and resistor caps is not a good idea. D8EA plugs should be OK for your bike. I see no reason to go '7'. As said I'd check the plugcaps resistance first. Do you know how to do it? Do you have a multimeter ?

[hondacr]

Resistor plugs and resistor caps is not a good idea. D8EA plugs should be OK for your bike. I see no reason to go '7'. As said I'd check the plugcaps resistance first. Do you know how to do it? Do you have a multimeter ?

Hi Thanks again for your assistance
No I am not sure how to check the resistance but I do have a multi meter [ never had to use it though.. ] but if you can give me a tip would be great.
one other thing I have thought of is could the carbs need balancing ? last time they were done was 3 years ago, the bikes done 2,700 miles since.

PS... if I am slow to reply after tomorrow... it is because I go into hospital tomorrow for a couple of days, should be up & running on Tues / Wednesday next week...touch wood..

Cheers

[Deltarider]

You can ride tens of thousands of miles without balancing the carbs. Honda made it so.
Plugcaps deteriorate over time and testing them should be in the 6000 miles maintenance interval scheme. Caps resistance ideally is around 5kΩ. 8kΩ is the max! You can measure the resistance in two ways, with the plugcaps still attached to their wires (1) or the plugcaps separate, once they're screwed of the wire (2).
I'd start with (1). Select 200kΩ range on your multimeter. With one probe in plugcap 1 and the other in plugcap 4, you're testing the secundary circuit as a whole and you should read around 23-31kΩ, knowing 5-8kΩ for each plugcap and around 13-15kΩ for the secundary winding of the coil. With the plugcaps removed and one probe against one high tension wire and the other against the other wire, resistance should be around 13-15kΩ. Each plugcap separate should read around 5kΩ. Plugcap is no longer good > 8kΩ. BTW, the primary circuit can be tested with the 200Ω range selected. The standard Honda coil primary is around 4,7Ω. Get well soon and succes!

[hondacr]

Thanks Deltarider I will give it a go & thanks also for the good wishes..
i will eventually keep you posted on the results of the Honda.

[PeWe]

This reminds me about fouling plugs in the middle of the 80's.
I got the advice to use Nippon Denso plugs. They worked for a few minutes, one after the other started to misfire and die completely. They were really black, spark was weak and jumped around all over the plug. Maybe too cold version. I use Denso today that work fine, X24ES-U.
Same sh!t with expensive  Bosch silver that maybe worked for 20 minutes longer

Back to NGK, I think D8EA and no problems. I did not change the carbs at that time. They must have been rather rich but did not sputter on low lift nor WOT. 836cc ported head, cam... I do not recall if that was with rejetted stock carbs or Mikuni 29mm smoothbores.
The caps I used then had no additional resistance so R plugs should not add any problems. i remember I used NGK R plugs.

I have recently found that too advanced ignition can be hidden by too rich jetting. Maybe that's how and why....

[hondacr]

hi guys, i had a longer stay in hospital than I expected  .. only got out last night.
back to the number 4 plug fowling [only number 4], my bike has PD carbs fitted which were refurbished 3 years ago fitted with 138 main jets, the bike is non standard no air box I tried K&N's but I was getting baulking at between 5 - 6K revs, so on a recommendation I tried velocity stacks & bingo the bike ran fantastic no plug fowling [ a nice light brown on all 4 cylinders]this went on for several months of great running, then the fowling started so I tried iridium plugs which made no difference so back the stock plugs mentioned previously, just before I went into hospital I put in another new plug in cylinder 4 & for 40 mile-ish it ran like a dream, then I noticed a very slight vibe & it felt that it was just not on full-song but still firing on all 4 pots, after another 5 miles or so it started missing again on pot 4 & eventually it stopped firing on pot 4, on arriving back home I took off the suppressor cap & popped a new plug in the cap to check there was spark from the lead out side the cylinder & it was a good spark, so I then removed the plug in the cylinder 4 & again black as night so I tried that for a spark in the sup-cap but nothing so obviously it was the plug that was totally crapped-up, I then gave the plug a good clean & tried it again out of the bike  to see if I could get a spark, there was a spark but it was all over the place around the plug head...you would probably say yes its a faulty plug, but I have at least 5 new plugs in cylinder 4 & I am sure they cant all be faulty

ps... I have not had a chance yet to try the multimeter 

[Deltarider]

Could be a faulty suppressor cap.

[bryanj]

PD carbs are notorious for blocking up the pressed in pilot jets

[hondacr]

PD carbs are notorious for blocking up the pressed in pilot jets

But the bike idles perfectly and as said previously runs perfect on  plug 4 when CLEAN, when plug 4 starts to fowl-up you cant feel it when going from Off throttle to accelerating.

it obviously going to take time to find the route cause, so will be trial & error...unfortunately nows not the time of year for trials nor am I fit at the moment...

[Deltarider]

Checking the plugcap and its connection is about the easiest you can do...

[hondacr]

Thanks Guys for your help will try all suggested when fit enough to do so & hopefully with the info given in will crack it.... eventually..

[bryanj]

I had a 550 k3 with the pd's on and it started nd idled fine but on the road was like a camel on casters, that was the pilots

[hondacr]

I had a 550 k3 with the pd's on and it started nd idled fine but on the road was like a camel on casters, that was the pilots

Are the pilots easy to get at ? or will some good carb cleaner fix it ?

[bryanj]

No to both questions i m afraid. The jets you need to use vice grips CAREFULLY pull and twist at same time then i had to soak for quite a while in cellulose thinners and use high pressure air with thin COPPER wire

[Deltarider]

Are you sure you have PD carbs? K6 originally had the oldstyle Keihins IIRC. Has plugcap #4 been checked for resistance? There's no point turning to the carbs before every item of the ignition has been checked.

[hondacr]

Are you sure you have PD carbs? K6 originally had the oldstyle Keihins IIRC. Has plugcap #4 been checked for resistance? There's no point turning to the carbs before every item of the ignition has been checked.

Absolutely certain they are Keihin PD [ I know they are not the original for the K6, I chose them because they look better on a café racer which the bike now is]
This bikes engine & carbs etc have been totally rebuilt except for the floats in the carbs, but after the rebuild, done by a professional SOHC engine specialist, it did run fantastic for several months.

Right now I am still recovering from spinal surgery so not really fit enough yet to be getting up / down & dirty.
I will keep you posted