Showing posts with label spark plug cap. Show all posts
Showing posts with label spark plug cap. Show all posts

Monday, September 13, 2010

Feeling much better thank you!

Well after some frustrations, some progress.
The spark plug caps came and got installed and didn't resolve the problem.  Well they resolved the problem of the resistance being 19 ohms on one plug and infinity on the other but the bike still wouldn't start.
We've only been working on her sporadically, some days not at all, but until today we weren't able to get the infernal machine to crank. A cough here, a sputter there but mostly a lot of nothing.
There is nothing exciting about tracing out the wires and hoping to find a loose one somewhere, so it was tinker some, walk away a to brood, tinker, brood... A couple semi-eureka moments (was that wire loose or did I just tug it a little too hard?) but nothing much encouraging. 
Finally decided to go back to the beginning and check timing and points. Some how ignition timing plate had slipped. Set that back and viola...she fired up.
She's still missing a little on the left cylinder (I don't think that set of points is properly set-up yet) but she was definitely firing some on both cylinders, and it ran long enough that I was able to get some readings on the charging system.  These numbers may be low but I guess they are better than nothing.  At idle speed (@ 1300 rpm) the voltage reading across the battery was 12.2 Vac.  At  @ 2000 rpm reading was 12.7 and at @ 4000 rpm it was reading 13.7.  I'm thinking this may be a little lower than desirable but it is positive so that's sorta OK right?
I didn't think about running the check on the alternator while I was working on her but tomorrow, after I go back through the points and timing I will check that as well.
I was encouraged enough today to forestall the the idea of parting her out on e-bay for another couple of weeks.

Friday, September 10, 2010

Logic and electricity

I'm not an electrician, not even close, but I can kinda sorta read a schematic some and know that wires, and switches and relays are very much like a computer program flow chart or a logic problem (both of which I studied in college about a 100 years ago and wasn't real good at but I do kind of understand the concept of "if A=>then B" and all that to some degree, and I did work in factory where sometimes I could logically convince the electrician where he should be looking to resolve the problem) so it really wasn't connecting with me as to why doing some static tests on a few component and removing a wire that wasn't going to be used would suddenly make the Honda not start at all.
But now I have a theory at least.
After we scrapped the idea of getting the electrical starter working (mechanical problem, not electrical) I decided to pull the wire, which was an add on and not part of the harness because of some previous owner's tinkering.
I took it loose at both ends, cut the visible ties and tried unsuccessfully to pull it out. Eventually the tank had to be pulled and more ties cut before it came free.
By now the battery is recharged and we want to start it to check some voltages while it's running to see if we can isolate the charging problem but it won't start. Not getting any fire, and not making any sense. Nothing we did should have made a difference, and it was starting so readily two days before.
When I initially reported that the battery wasn't charging some suggested looking for loose wires. A while later, since I seemingly wasn't getting any juice from the coil, I'm looking for some test for the coil. Find one, and the first step is to take the black/white wires loose from the coils to do a test...one of them is already kind of loose in the connector.  Ah-hah, maybe that is the charging problem, but it never came to the point of finding that out because the testing indicated that there was a problem with the spark plug caps and now I wait for those...
But this morning I get a revelation...the loose wire wasn't the charging problem but maybe it was the starting problem.  Looking at the diagram I find that the black/white wire at the coil comes from the run/kill switch, and with that circuit open I'm guessing I found the problem with the no fire issue.
And I'm assuming that the way this wire got loose is that when I tried to pull out that starter wire it tangled in the wire to the coil and pulled it loose...and that is why removing the starter wire made the bike not start (with the kick-starter.)
So I'm hoping that this will resolve the starting problem and that the new spark plug caps (which should be here today or tomorrow) will resolve the firing on one cylinder issue, which still leaves the charging problem...

Wednesday, September 8, 2010

more baby steps

still not wanting to start, and remember that when it did it seemed to not always fire on the right cylinder.
more routine tests, this time the ignition coil.
according to the book you short the wires from the coil and check resistance from shorted wires to the spark plug wires.  you should get the same or very similar readings on both sides. I'm not getting any readings. [what, oh, wrong setting on the multimeter]
when I remove the spark plug caps and check continuity on them I get 10 ohms and 8.5 ohms.
when I do the above check of spark plug wires without the caps in place I get 10.3 and 10.4 ohms. (someone on one of the forums I go to for advice says this is a good number for the coil.)
when I install the caps again I get 19.0 and infinity. when I switch the caps side-to-side I get infinity and 19.0.
sounds like a bad cap to me. (and the bad cap was on the right side which has been observed as not firing consistently)
2 suggestions from different forums suggests that my evaluation is likely correct.
ordered some caps (paid a little extra for expedited shipping since they were so cheep) and now I wait again.
if I get lucky the new caps will make it easier to start and resolve the firing on one cylinder problem.