Topic: 1980 CB650c Rest-o by a crabby "old-timer"

[Soos]

Perhaps thats why I have never really had that problem?(or not long enough to really notice it?)
I went with 3.0 ohm dyna coils fairly quickly as one of the first few "upgrades" on my cb650.


l8r

[Frankenkit]

er... pulser generator, sorry, Soos.

[MikeB]

Kit

mine seemed to be bad when I first put the meter on it but when I moved the wires around it would read ok.
Try testing the pickups while moving the wires around right at the pickups, maybe loose or broken conn.
this was my prob. on the one with blue wires, (very tight bend) think the wire is broke right where it goes into the pickup, could get it to work by moving it around
   
I replaced it with a pickup i got of ebay , from a cb 900, don't remember what year ?, the plate was diff.  but I just mounted the pickup on the 650 plate, still have the other one around
if you need one let me know you can have it

Mike

[Hush]

Hmm I never thought of your problem being on the other side of the engine?
You could well be right, I know mine is definitely related to a screwed stator so I'm happy, gonna be broke but happy.
You do have the solution at your fingertips though eh ladies!
The parts bike could supply a lovely set of test pulse generator coils for you, hey it's how I found my stator problem, I'm running on a borrowed one right now but it was a sure fire way of proving the problem.
You can always put them back if there is no difference.
As I remember it your problem had zip to do with your battery (unlike mine where the battery was completely drained after riding) so yes maybe........TT waddaya think?

[Frankenkit]

TT has already shot me down on this thought, but we'll see. 

[Frankenkit]

ok. Probably a really dumb question, but before I even think seriously about putting on the other pulser generators,

Is this going to involve a timing light, TDC, somehow by voodoo finding 10* past TDC, etc etc?
...cuz me and TDC don't mix.  I couldn't find it with both hands.

[mlinder]

You can static time easily with these, and they will be more or less correct once static timed.
All you need is a bulb that can handle 12v and two pieces of wire...

[Frankenkit]

ok, where would the timing light attach? The shop manual's instructions are a little vague, just saying " Get 1 or 4 near TDC, Compression.  Rotate the crankshaft counterclockwise and aline the 1.4 S-F mark with the index mark.  The timing's correct if the narrow projection of the 1.4 pulser generator aligns with the rotor tooth.

...then, to adjust, loosen the plate screws and rotate the plate until it's aligned the way is says above.

Do I still need to go get a straw or something to stick down the spark plug hole of 1 or 4 to determine TDC compression?  I'm not sure why it's so hard for me, but since the bike is running (just not starting when hot) I'd REALLY feel lousy if I killed it now.

TT, your reasoning is pretty much why I'm not really sure why the replacement of the pulser generators helped one guy on the 650 forum out at all.  It doesn't make any sense to me.  Then again, he hasn't posted any further info, so maybe that WASN'T the solution after all, but he won't admit it.  The 650 forum seems a little spartan at times with their solutions.

I'm now wondering about the starter again and the ideal lubrication of the bushings, if perhaps they expand with heat and, with insufficient or inferior lubrication, 'stick'.  They have just fantastic torque, though, when cold, so I would think it'd take something equally fantastic to make them stick.

OTOH, I know my oil pressure (and probably compression, too) go way up when the engine's good and warm, as evidenced by the heavy weeping down from my valve adjustment cover and from the head cover to a lesser extent.  I'm wondering if, as Marti said, the increased compression would put more strain on the starter AND/OR since the old oil was so muddy/filthy, if this starting issue is at least slightly improved now with clean (and probably slightly lighter bodied considering the previous contaminant) oil.  I have to admit, I forgot to check the difference after the oil change. 

As long as it runs, I'll ride the hell out of it.  Even with all this stuff going on, the oil bolt crap with needing to grind it off, the leaks, the etc etc, school, exams, and work, I've still gotten in around 70 miles.  It's not much, and you guys probably do twice that in a day, but I'm still really learning and it's more than this bike has done in a while.   so there. 

[Frankenkit]

another thing I just thought of- if the pickup coils/pulser generators don't die altogether, but maybe increase in resistance when hot, could that explain a higher than average draw, which, while not killing a running/charging bike, could sap the electrical amperage/voltage needed to go to the starter AND create an excessive drain?

I'l try your test today. Thanks.

[MickeyX]

I'd just like it to stop leaking right now. We had an old timer at the parts shop tell us last night that these will never stop leaking. When you go to higher revs, they will just spew so stay in the lower range. I'm not sure what to think of that one. I would assume that one would have more pressure and if it's going to leak, it would do it then. But to say that they all will leak no matter how you fix them... that seems to be a stretch there.

I've been doing some cross checking on carbs and rebuild kits. I've found some interesting to me facts and I just want to finish up my check before I post it all. Since the "parts bike", as y'all like to call it, needs the carbs rebuilt, I've been trying to find kits for a 1979/1980 and can only find 2 sources, both at $32/carb + ship. That seems a bit steep to me since we have to x4 that number. I'll pay it if that's all there is out there. But what if that isn't the only way to go? More to come later... 

Btw Hush, there is a nice looking stator on feebay right now that may go for a decent price... not new but good condition. 

[MickeyX]

Thanks TT. We'll get a meter on it while we are out there later today. We both are inclined to believe that this is just a red herring for Kit's issue but now that we are curious, we may as well check it out.

As for the carb kit issue... I've noticed, as I'm sure many of you have, that the carbs really didn't change much over a few of the years and models. I really hate it when, for all of the bikes around the 650, the gasket kits are $14 thru Honda but the 650 is $43. I've looked at each individual component, the bowls, the top set... the part numbers are the same from 78 550 thru 77 750 (probably more but I stopped there), depending on which model 750 you look at. The gaskets and rubber o-rings are the same and fit the same parts. From what I can tell, the air screw and the jets have changed and that's it. Am I correct on this? So why the highway robbery on the gasket set for the 650?

I'm probably going with the full Keyster set this time for each anyway because who knows what the POs did to it before us. But for my own reference, if I just need a gasket set in the future, I know I can go with a 78 550 and pay $14 through Honda instead of a whole Keyster setup for $32 or what ever they will be going for by then. Kit thinks maybe we should just replace the whole bank with a 550 so we can change out the jets and not have the press in type. Anyone have an opinion on this? Do things line up front to back or is there some spacing differences between carbs that isn't apparent on the pics? We could probably get a bank at the shop for cheap and just redo those and "fix" the changing jets issue all at once... maybe on both bikes.

[mlinder]

Thanks TT. We'll get a meter on it while we are out there later today. We both are inclined to believe that this is just a red herring for Kit's issue but now that we are curious, we may as well check it out.

As for the carb kit issue... I've noticed, as I'm sure many of you have, that the carbs really didn't change much over a few of the years and models. I really hate it when, for all of the bikes around the 650, the gasket kits are $14 thru Honda but the 650 is $43. I've looked at each individual component, the bowls, the top set... the part numbers are the same from 78 550 thru 77 750 (probably more but I stopped there), depending on which model 750 you look at. The gaskets and rubber o-rings are the same and fit the same parts. From what I can tell, the air screw and the jets have changed and that's it. Am I correct on this? So why the highway robbery on the gasket set for the 650?

I'm probably going with the full Keyster set this time for each anyway because who knows what the POs did to it before us. But for my own reference, if I just need a gasket set in the future, I know I can go with a 78 550 and pay $14 through Honda instead of a whole Keyster setup for $32 or what ever they will be going for by then. Kit thinks maybe we should just replace the whole bank with a 550 so we can change out the jets and not have the press in type. Anyone have an opinion on this? Do things line up front to back or is there some spacing differences between carbs that isn't apparent on the pics? We could probably get a bank at the shop for cheap and just redo those and "fix" the changing jets issue all at once... maybe on both bikes.

Soos has a list of carbs that will fit right up to the 650. Dunno off hand where the list is, but I'm sure he's be happy to dig it up for you

[MickeyX]

Hiya Mark. so, as you can see, I don't mind modding this bike the way Kit does since she's trying to keep hers stock. We can just use these carbs for her bike if she would ever need a spare set. Im thinking a set of 550 carbs and rejet, 4-1 pipes, drag the seat, redo the fork, straight bars with pullback risers, tinted gray signal lights... FIX THE CHARGING SYSTEM... 

[Frankenkit]

...for the pullback risers, you're going to need to relocate your fuse panel.  Good luck with that.

...I did a lot of that stuff because I *had* to, not necessarily because I *wanted* to.  ...but I do like my detailing.  mmmm pretty shinies.

[MickeyX]

I have wrenches, power tools and an imagination, dear. And, I know how to rewire stuff. I'm dangerous. 

Off to see a guy about some helicoils...

Yea, I get to use my dewalt drill on your engine...

muhahahahahaha!!!!

[mlinder]

Mickey, I noticed that the carbs from the gs550's and gs750's are spaced about right for the 550... haven't checked to see if they are spaced right for the 650.

[Pinhead]

I don't know if it'll help you, TT, but here's a diagram of the internals of the sparkers.



AFAIK, we have the same ignition as the CBX's; I've found a lot of information HERE.

From the CBX article with regards to the Spark Units:

TPI’s spark units have easily recognizable failure modes. A common one is when an attempt is made to start the bike after it has sat awhile and the battery is low. During starting, battery voltage normally dips when the starter is used but with less to start with, the battery’s voltage drops too low for the spark unit to operate, and the engine will not start due to loss of spark. Meantime, the transistor is overheating, and will soon permanently fail. This is such a known failure mode that Honda later added time-out circuits to their TPI systems, as did also other manufacturers. Another possible route to failure is the unthinking substitution of ignition coils having too low a primary resistance. Such coils will burn out the spark units. You have no doubt heard of this. High performance ignition coils have higher potential voltage output because they have larger primary to secondary winding turn ratios. There are two ways to build a coil with a larger turn ratio - either leave the primary the same and increase the secondary turns, or leave the secondary the same and decrease the primary turns. The latter method was once very popular. However, it results in a coil having lower than stock primary resistance. While not big deal on a points bike, whose points will merely arc a bit more, the transistors in a TPI system will not endure the increased current flow through the coil for very long, and the spark units will fail. We’ll address this issue again in Part 3. One thing you do not have to worry about with spark units is failures due to loss of ground. Their metal boxes do not physically ground, but rather, the spark units get their grounds through the green wire feeding back into the wire harness. And here are a few tips. When the ignition system is acting up, but it is mostly when the engine is warm, don’t suspect the spark units. The pulsers are likely the problem. When the ignition performs badly whether hot or cold, then the spark units become more suspect.

[Hush]

Kit, pull #1 or #4 plugs out, remove corresponding valve cover, use your straw? I use a very thin screw driver but whateva to find if piston at top.
When piston at top, tap your tappets, if they are touch lose then valves are closed and piston is at TDC or close enough for these pulse generator units anyway.
If unsure, rotate till piston again at top, if tappets now lose that is TDC.
Align centre rotor with the wee tip on the closest pulse generator coil.
That is the easiest if not precise way I did mine and when I got shop to check they said it was spot on.
I don't own a timing light and the bulb trick only works on bikes with points so try this Kiwi close enough is good enough way.

[mlinder]

Kit, pull #1 or #4 plugs out, remove corresponding valve cover, use your straw? I use a very thin screw driver but whateva to find if piston at top.
When piston at top, tap your tappets, if they are touch lose then valves are closed and piston is at TDC or close enough for these pulse generator units anyway.
If unsure, rotate till piston again at top, if tappets now lose that is TDC.
Align centre rotor with the wee tip on the closest pulse generator coil.
That is the easiest if not precise way I did mine and when I got shop to check they said it was spot on.
I don't own a timing light and the bulb trick only works on bikes with points so try this Kiwi close enough is good enough way.

I've used the light with my dyna-s ..........

[MickeyX]

She was taught to use a thin straw so she can't possibly break the end of a screwdriver tip in there or put a ding in something. 

We got a helicoil kit from Harbor Freight. It was a lot cheaper than the helicoil brand and came with everything we need. I also picked up a 90deg turn for the drill so it will fit without removing the motor. With the short drill bit, the drill itself would have been right up against the crossbar with not enough clearance.
Can we do this with the valve cover on? Kit is worried about getting shavings in the oil. Maybe duct tape over the opening if we take the cover off? I know Marti, we will use grease on the drill bit.  Does anyone have any good ways to really clean out the drilled hole when we are done before we put the new thread coil in? A magnet isn't gonna do the trick, unfortunately.

[mystic_1]

Does anyone have any good ways to really clean out the drilled hole when we are done before we put the new thread coil in? A magnet isn't gonna do the trick, unfortunately.

There's a specialty tool for stuff like that which I am occasionally forced to use, known as a "vacuum cleaner".



mystic_1

[MickeyX]

Did you just explain to 2 chicks how to vaccum? That's funny right there. 

Ok, enough messing around. Kit is getting impatient. Off to drill an engine and hopefully not screw it up. Wish me luck. If I mess up, the other bike will definitely become a "parts bike" afterall. 

[martino1972]

what you girls should do with the "parts" bike,is make it into a tank girl or rat bike.....knock yourself out on being creative,that way you don't have to worry about leaks,perfect shiny parts etc......that way you can switch between anal perfect bike and rat bike....keeps sanity in balance.....

[MikeB]

The pulser units are spark triggers.  They can cause loss of spark when bad.  Loss of spark does not cause the engine to crank slowly or for the battery to deplete quickly.  I've not dealt with these directly or dissected one, but my understanding is that electrically, there are simply coils of wire inside them.  If the internal coil breaks there is no spark.  If the internal coils short, the symptoms would vary depending on where the coils shorted internally, and how the pulser units are designed.  I would expect there to be a magnet that moves past these coils, and that motion would generate a voltage spike as it pass by the coil (its called induction, if you are interested).  The spark units would interpret this pulse signal and then make the coils do their thing with sparking the plugs.

I understood the problem with Kit's bike to be starting when hot.  If the spark units were going faulty with heat, it would die when it got hot all on it's own, without giving you the choice of engine stop.  It wouldn't wait for you to stop the engine to go bad.
Slow cranking, or short duration cranking, is either weak battery, excessive current draw (caused by faulty starter or increased rotational resistance of the motor).

Well, you asked what I think.  But, I admit I don't know for certain what's inside the pulsers or the spark units.  Remember, I don't have a 650.  And, no one has offered to give me one.  So, I'm working on theory and knowledge of things electrical.

Cheers,

 

TT
 this makes sense that it shouldn't cause a (hot start prob.)
but if the pulse gen. had a higher than normal Res. when hot  would this or could this cause an excessive current draw from the spark units or ign. coils ?
and possibly cause low battery current ?
I too am trying to learn from this 

Kit
if you have another fully charged battery to throw in after running the bike to the Hot start prob.
and see if you still have the same prob. it might help to narrow down the possible problems ?
if it fires right up would it not eliminate your starter or engine problems ? and would than be in electrical system ? either to much current draw? or not charging properly to keep the battery at proper levels ?

if it does the same thing then would guess that at least your charging system is probably ok
This is def. a challenging problem.
 
Remember There are no problems only solutions
Best of luck

[mystic_1]

but if the pulse gen. had a higher than normal Res. when hot  would this or could this cause an excessive current draw from the spark units or ign. coils ?

Higher resistance = less current flow.

Lower resistance = more current flow.

mystic_1