Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: Mikep328 on September 02, 2024, 04:01:05 PM
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Along with some wiring clean-up I'm doing, I had decided to remove the E-ignition and reinstall the OEM points ignition. Yeah, I know, sounds stupid but that's a different discussion...;)
I was installing the OEM points system back in the bike after cleaning/lubing the advance mechanism. I got everything all set up/static timed but couldn't get it to start - an occasional backfire. Fooled around a bit, racking the points plate back/forth to see if that would make any difference but no help. I pulled a couple of plugs and, with them connected/sitting on the head, there was a good blue/white spark. I was getting annoyed/frustrated and I learned long ago that when that happens, to STOP!
So I walked back home (1/2 mil from garage) figuring I'd look at it again tomorrow. I was drinking a G&T when I literally slapped my palm against my forehead...JEEZ!!!
I had completely forgotten that although the advance unit can only mount in one position, the points cam can mount in either the correct position or 180 out. When I had removed the points cam to clean/lube I didn't pay attention to ensuring I put it back as it was. I didn't have the energy to walk back to the bike, especially after the 2nd G&T but I'm quite confident that reversing the position of the points cam tomorrow will resolve the issue.
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Unless you dismantled the advancer unit it only fits one way as there is a locating peg. IIRC the blue wire should be on the points on your left for 1/4. The yellow on the right for coils 2/3.
Convention is to have the left coil as blue for 1/4, so yellow would be the right coil 2/3.
Easy done I had my plug leads wrongly connected in my 400 so it ran almost for 100 miles on two cylinders with lots of poping & banging!
Reading your post in detail sounds like you must have taken the springs off - in that case you are right.
I have since cleaned my base plate and removed the Hex screws for JIS ones. Ken advised me it's too easy to strip a thread in the base plate with the Hex heads.
.(https://live.staticflickr.com/65535/53718155557_1acd67798c_h.jpg) (https://flic.kr/p/2pQTA8P)500 ponts plate (https://flic.kr/p/2pQTA8P) by Macabe Thiele (https://www.flickr.com/photos/187487200@N03/), on Flickr
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If you've put the points cam in 180 out, then you'll not be the first, or last to do that. Easily done.
Easy to check too, just swap the two wires from coils to points over with each other to functionally check that error, if it starts like that it will confirm the error, showing you need to dismantle and swap the cam and wires back over to make it std setup.
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"I have since cleaned my base plate and removed the Hex screws for JIS ones"
I removed all the previous owner-installed hex head screws (literally every fitting on the engine) last year, replacing them with the JIS OEM type screws.
Thanks for the quick-check tip K2, I'll make that check first thing tommorow!
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Nothing like a G & T to clear the head Mike! 😂
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Allen screws/socket head set screws. 😁👍
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Yeah, I put them on all my Japanese bikes bike in the day...now I'm taking them off and putting JIS screws back in their place. And, back in the day I installed E-ignitions as soon as they became available and now I replaced the DSS E-ignition with OEM points. Go figure...;)
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I did the same Mike with the screws, never liked the look of the Allen head screws on the 550, kept the e/ignition don’t have a problem with that. Still got the points plate if i need to fall back to old school!
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They say that beauty is in the eye of the beholder, and I always thought that to see a nice smooth alloy casing adorned with those protruding socket head bolts gave it the appearance of something from a piece of WW1 military equipment. BUT!!! back in the day, I have also used up my full quota of obscenities trying to remove the original screws with a conventional Philips screwdriver, nobody seemed to have heard about JIS then! Earlier this year I was playing with a CL160, and I have to admit that when I replaced the clutch cover I compromised and obtained some rather neat little button head socket screws.
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Back in the 1960s when I had to remove the clutch cover to separate the clutch plates as my 250 Dream, it had stood in a shed for a couple of years I had inherited chewed screw heads.
At great expense I purchased an all steel T shaped handled JIS driver from Fred Palin's the local dealer. You could hammer the end into the screws and apply great force via the T handle. I had to drill the heads off 3 or four of the screws.
Hence why I am happy to use SS Allen key headed screws on side covers but not in places where they can fill up with water. I always blamed the quality of early Japanese alloy.
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Stainless pan-head allen screws don't look too bad, and they tend not to chew up.
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At great expense I purchased an all steel T shaped handled JIS driver from Fred Palin's the local dealer. You could hammer the end into the screws and apply great force via the T handle. I had to drill the heads off 3 or four of the screws.
Palins, a blast from the past Ted. There was Bob Minions too. Still there last time I knew but Palins not the case. Also Samways, who again were still about but more bicycles stuff and smaller scooters? Samways for the highways was the slogan as I recall...
More local to me at the time in Duffield was Bill Lomas in Milford. Ex racer and his son Mick was no slouch on a bike.
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I reversed the wires as K2 suggested and it ran perfectly. I then switched the points cam around and put the wires back to normal. One issue is that with the point plate at the correct 1-4 firing position, the 2-3 subplate has to be moved to it's absolute max (advance) position for the 2-3 timing to be correct and it's just barely able to achieve that.
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I had the same issue Mike, ended up replacing the points. Quite sure it was due to the heel of the points being worn!
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Likewise, I suspect the problem is also more pronounced with none genuine points as well as heel wear.
I ended up changing my baseplate for my original 400 one as I fitted electronic ignition on the 400.
Once my 500 is run in I'm thinking of switching it to electronic.
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Yes your probably right Ted, the ones I replaced them with was old one off my redundant 550k3 plate but they certainly had more of a heel on them.
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At great expense I purchased an all steel T shaped handled JIS driver from Fred Palin's the local dealer. You could hammer the end into the screws and apply great force via the T handle. I had to drill the heads off 3 or four of the screws.
Palins, a blast from the past Ted. There was Bob Minions too. Still there last time I knew but Palins not the case. Also Samways, who again were still about but more bicycles stuff and smaller scooters? Samways for the highways was the slogan as I recall...
More local to me at the time in Duffield was Bill Lomas in Milford. Ex racer and his son Mick was no slouch on a bike.
Yes Bob Minions have moved a couple of times iirc. My NSU Quickly was from Minions when they were on Park Street, they are currently on London Road now RE & RA dealers not sure if it's still owned by the family though as Wilf & Lionel Minion must have died decades ago. I bought a fairing for my Ariel Arrow from Barrie Rodgers that were opposite where Minions are now.
Samways ditched motorcycle sales when they moved from the corner of Mill street to Ashbourne Road selling only pedal cycles once the old stock was gone - closed a few years ago as they could not complete with Internet Prices.
Bill Lomas - did they also have a branch in Clay Cross or Chesterfields way?
Update - Company records show it is still owned by the Minion family!
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Yes but that was his son Mick's project in Clay Cross. I may be wrong but I think they use the unit now for some classic bike museum....
I only ever knew Minions to be on the road south of Derby near DRI as was. There was a dealer diagonally opposite, think they were Yam and Kwak specialists! Name escapes me but think faint a recollection they are still trading in Nottingham?
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Yes but that was his son Mick's project in Clay Cross. I may be wrong but I think they use the unit now for some classic bike museum....
I only ever knew Minions to be on the road south of Derby near DRI as was. There was a dealer diagonally opposite, think they were Yam and Kwak specialists! Name escapes me but think faint a recollection they are still trading in Nottingham?
Remembered - That dealer was Roy Pidcock.
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I think Granby's took the site when Pidcocks closed that branch.
Granbys Ilkeston off Bath Street was where I bought my XJ900 back in 1995.
I think Granbys Ilkeston closed before Covid time around 2016..https://britishdealernews.co.uk/news/uk/granby-closes-its-doors/
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Yep that makes sense!
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Walked back to the garage and re-did everything. I ended up reducing the point gap to the minimum and now there is sufficient timing adjustment/additional movement available.
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An interesting outcome with the points system is that the bike starts much quicker from cold than it did with the E-ignition. The same is true when the engine is warm. In that situation, when I push the starter button, the engine is running literally before I can release the button.
I have no idea why this should be the case - timing was the same with both systems.
On the down-side, contrary to my expectations, the points system seems to require more power than the E system. I base that observation on the charging voltage/RPM. With the E-ignition and the LED running light (parking light) on, the no-discharge point (12.6v) was 1500 RPM per the bike's tach. With the points it's around 1700. I expected the opposite. Shows you what I know! ;)
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Whose Electronic Ignition system was it Mike?
My experience is that more cranking is needed with retarded ignition. Over advanced often results in a stall immediately after starting. Sounds like you have it spot on.
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The E-ignition is the DSS system, installed by the previous owner.
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I have no experience with the DS system, my 400 has the Dynatec full system (including coils) that is known to be power hungry.
I have an unbranded E-sytem that Bryan supplied me with for the 500 but to date I am using the points system until it's run in.
The DS system has some circuitry on the mounting plate looking at the listing whereas both my systems have neither - just what look like points type mounted sensors both being adjustable?
The visual difference between the Dynatec & the unbranded E unit is the Dynatec has much thicker wiring.
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On my "bed-in the front brake" run today I did a number of WOT/red line pulls and the bike pulls harder with the OEM ignition than it did with the E-ignition. There is a noticeably stronger surge going through 6000-6500 RPM than previously - it was quite noticeable.
I have no idea why this should happen. Timing is the same as it was with the E-ignition. I thought that maybe the points allow more current to the coils than the E did. But there has never been any indication that the spark was lacking at high load.
Re timing...I said it's the same but that may not be exactly correct. The timing with E ignition was spot-on with a strobe both at idle and at full advance (around 2500 RPM). When I installed the points I set the timing statically - no strobe - so I didn't verify the max advance. Also, the advance mechanisms were from different original (to Honda) suppliers. Of course the characteristics should be the same but since I didn't strobe the points, I can't be sure that the max advance is identical for both.
In any case, it's running great on the points!!
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I agree the most likely cause is the advancer curve being closer to original.
Have you eliminated the Placebo effect Mike - its a proven effect on humans. ;D ;D ;D
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"Have you eliminated the Placebo effect Mike - its a proven effect on humans. ;D ;D ;D
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Good point! I know that the "Butt Dyno" is notoriously inaccurate and it's possible but the tach really did seem to move much quicker thought the 6000-7000 range.
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Without knowing the spec of E system triggering characteristic it may potentially be hiding something of influence.
Specifically, the dwell characteristic may be different. The points using 5 k ohm coil resistance and fairly long dwell to accommodate high rpm drop off (same angular movements, but as rpm increaese then dwell drops away in time that the coil "sees" ) so you get good saturation at lower range with longer dwell tbat may influence the outcome.
The E systems often make use of constant dwell, irrespective of engine speed. This may often be paired with lower coil resistance as it's not needed to mitigate for changes in this dwell time.
The E may possibly need a 3 k ohm coil set to fully utilise and saturate them through from low to mid rpm range. Could account for change in starting too.
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Great explanation K2-K6 that I do not even begin to understand as a complete sentence - way over my head.
The individual words yes, as far as the gestalt goes.....er no.
I'm left with the feeling it's sumat to do with the advancer magic.
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The actual "advancer" is the same on the OEM and the DSS electronic ignition. The E-ignition retains the advance unit/associated springs/weights of the OEM system. It just replaces the points plate with the electronic plate and the points cam with a different cam with magnets in it. The advance is still controlled by the weights/springs.
But if I understand correctly, the dwell time of the system might be different which affects the charge of the coils and the subsequent potential spark energy.
Also, as I mentioned in the earlier post, the advance unit I installed with the OEM points is a stock Honda unit but it is not the same one that was in the bike with the DSS. SO there MIGHT be a slight difference in the max advance due to manufacturing tolerances/wear difference. As I said, I didn't check the "new" one with a strobe. The old one (with the E-ignition) was exact at both idle and at max advance per the strobe.
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Checked/set timing with a strobe and the OEM ignition is set per specs, as was the e-ignition. The bike clearly runs a bit better on the OEM system. Only items that remain unknown is the dwell spec on the two ignitions and the fact that the 1-4 and 2-3 timing cannot be individually set with the e ignition. Unfortunately, I never thought to check the 2-3 timing with the e-ignition so it may have been correct...or not.
Re dwell...I have to admit that I ASSUMED that the dwell would be "better" with the electronic since, with points, the dwell diminishes as the RPM rises. But I had assumed that longer dwell is always better than shorter dwell but apparently it's not. Too much dwell can also cause problems.
And, worth some thought...some e-ignition ads rave about their constant dwell as eliminating the "problem" with the decreasing dwell of point ignitions above 5-6K RPM. Sounds like a reasonable claim that should "enable" better spark production at high RPM with e-ignition. But then there's the fact that Honda was spinning competition engines to 20,000 RPM on points in the 1960's! So clearly, that particular E-ignition claim is not necessarily valid.