Sunday, July 29, 2012

False Starts

False start #1 (the real one)

When the TA stopped running just 20 km outside of Humaitá, the first assumption was an open circuit in the ignition wiring, like we had seen before.  It wasn't.  Turns out the ignition fuse was blown, so in went a spare.  Figuring the fault was either in the connector from the Run/Stop switch (as in Costa Rica) or the Run/Stop switch itself, Mike checked those for continuity and all seemed good.  Turning the ignition to On immediately blew the fuse again.  Do'h.  A complete (yet not thorough) search did not turn up the little baggie of spare fuses.  With 1 more spare at hand, and after more revision of the wiring, we tried once more.  Do'h!  It's a frustrating sight to see your last spare fuse (that you can get your hands on...there were more...just hiding...) burn up before your eyes.  Time to find more fuses.  And more importantly, find the ground in the ignition wiring.

Thankfully the next 2 vehicles that passed us coming from Manaus towards Humaitá were a couple of caravaning pick ups, who gave us and the TA a lift.  They were great.  They dropped us at the Honda moto dealership and wouldn't even let us buy them lunch for their efforts.

(2 pick ups drove straight through the night from Manaus, taking around 27 hours to cover the 600 kms.  We slowed them down a bit)

The Honda shop techs were happy to lend space, tools, advice, and info - like where to find fuses.  The place they mentioned didn't have any fuses, but the owner had Mike jump on the back of his little 150 and took him across town to get a few.  Brazilians are fantastic.

(at Canopus Honda.  The first nights we stayed in Humaitá we didn't even venture across town to the "other" main street where the shop was located.  It opened up a whole new world for our additional few days.)

The electrical ground turned out to be within an aftermarket CDI controlling spark for the front cylinder.  Whenever it was plugged in, the ignition fuse would fry immediately.  After a complete check of the ignition wiring, cleaning of the Run/Stop switch contacts (couldn't hurt), and CDI swap, Mike took the bike for a test ride and all seemed good.  As it was late afternoon by this point, Jill had already checked back into our trusty old pousada.  Mike loaded the TA back up with all of our gear and started over to the pousada.  On the way, she dropped to one cylinder, characteristic of a CDI failure.  Turns out the extra juice brought on by the shorted aftermaket CDI toasted the good OEM one, too.  Now we put in our last spare CDI (which are now only Honda OEM parts, given how the aftermarket units tend to fail with a little too much gusto) and waited until the morning for a longer test drive close to town.

False start #2 (test drive FAIL)

On our longer test drive, the TA still had an obvious miss just off idle.  There were few items left in the ignition system to be inspected - the 4 ignition coils, spark plug leads and caps, and the pulse generator coils.  All 4 caps showed spark with the good CDI units in, but they were easy enough to check.  One ignition coil and lead showed intermittant failure between the primary and secondary coils.  The pulse generator coils are assumed to be fine as they would be unlikely to fail (and are a hassle to check).  So a replacement ignition coil was found.  But as it was Saturday, that turned out to be a bit of a hassle.

A bigger hassle yet was that we didn't find a magnetic pick up tool.  Why would we want one of those, you ask?  Because in the process of pulling the ignition coil, Mike managed to drop the nut into the front spark plug hole.  Dumb.  We found a piece of magnet from a cheap flashlight, but it was too big.  And the nut was out of reach of anybody's grip.  But with just a little less height, we thought we could get it.  So we pulled the valve cover.  Turns out it was a good time for a coolant change, too, as the cover didn't want to make it past a solid coolant tube connected to the front cylinder.

Sunday's chores turned out to be finding fresh coolant and fishing a nut out of the front spark plug hole.  This may be my favorite use of Gorilla tape yet.  Jill was able to move the nut to a relatively accessible location then stick it to her Gorilla finger.  Success!

(Jill's Gorilla (tape) finger showing off its catch)

Buttoned her back up and test drive again.  But still a miss just off idle.  Now to the fuel system...

False start #3 (why did we load the bike for this one?)

At this point, Mike was set on getting the bike running right before heading out on our drive through such a desolate stretch.  So he pulled the carbs to check the pilot jets.  One was completely clogged.  Replacing them was not possible in Humaitá, so we did the best we could to soak them in carb cleaner.  After plenty of soaking and spraying, the jet was improved, but still not perfect.  As good as we can do, though.  Talking to the shop where we bought the cleaner, they mentioned that the gas in that area is notoriously bad, causing similar symptoms (low RPM miss, especially noticeable when engine cold).  Combine that with a clogged pilot jet and that would definitely explain the miss.

The good news is that the miss was lessed substantially by the carb cleaning.  But sadly still present.  At this point, we had done what we could.  It was far past time to get on past Humaitá (a week was more than enough time to rest, as was our original plan).

For real this time...

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