Topic: Barely made it home yesterday...

[fmctm1sw]

Took my '72 350F out yesterday in continuation of the "proving" phase of this project.  The bike was running great and I decided to take it out on the interstate.  Bad idea.  Lots of construction and I ended up in bumper to bumper traffic, with lots of bumper to bumper before I hit the interstate as well.  Even before I hit the interstate I could feel a slight loss of power at take off from a stop.  It got worse on the interstate but once moving the bike really took off.  I started to wonder if I was too lean at idle or overheating maybe.  Eventually I was able to run it up to 75 for a mile or so before exiting.  I knew something was very wrong while coming off the off ramp though.  Sort of like the time my points closed and I was only running on two cylinders, but much worse.  It stalled at the next stoplight.  I pulled it off the road and was able to get it running with a lot of choke.  I ran it that way for a short while and it started running ok again.  Further along (I'm desperately trying to get home at this point, mind you...) it stalled again.  I got it off the road and pulled 1/4 plugs and had good spark.  4 did appear wet but it had good spark, and the bike started running with the other 3 still in!  I got it started up again and made it home, running very well at that.  I got home and pulled my plugs and they looked fine.  I pulled my petcock bowl and found crud in it.  Way back when I did my tank with toilet bowl cleaner, it flash rusted pretty bad.  I chose to ignore it in an attempt to get the bike to the point where it was road legal so I'm hoping this was a simple fuel starvation problem.  We'll see...  I just ordered a POR 15 kit...   


*edit* just had a thought...  Gas cap vent?

[HondaMan]

This also sounds like a coil with one of the spark wires broken inside. Try tugging on the sparkplug wires, see if they come out of the coil. They should not. A severely burned-out resistor cap is also a possible, but normally only shows up this way in humid climates.

I just went through this (again) with my K2 two years ago. The #3 wire was corroded in two inside the coil. When I tugged on it, it came out. I pushed it in as far as it would go, and it would run OK between 2000 and 6000 RPM, but cut out at idle and above 6K. Getting the new coil solved it, of course. This is not the first time in 36 years this has happened to it.

My poor brother went all the way across Kansas from here in Colorado after we had toured the Southwest one summer together. His 500 started acting up about 100 miles from here, and he changed points (twice), condensors, flushed carbs, tank, new plugs (twice) all the way across Kansas, 100 miles at a time, until he decided all that was left was coils. It ran 9 more years after that, then he gave it to our little brother who rode it another 5 years.

[BeSeeingYou]

Just a comment on your gas tank issue.  When you use an acid to clean the tank follow it with a rinse of water and baking soda to neutralize the acid.  Rinse this out with water and then a rinse with denatured alcohol to get the residual water out. Next either fill it with gas or give it a coat of tranny fluid if you will not be using it or awhile. I did this and not even a trace of flash rust.

[fmctm1sw]

This also sounds like a coil with one of the spark wires broken inside.

Thanks... I wouldn't have thought about that for while.  I actually have a spare set.

Just a comment on your gas tank issue.  When you use an acid to clean the tank follow it with a rinse of water and baking soda to neutralize the acid.  Rinse this out with water and then a rinse with denatured alcohol to get the residual water out. Next either fill it with gas or give it a coat of tranny fluid if you will not be using it or awhile. I did this and not even a trace of flash rust.

About the only thing I didn't do that you listed was baking soda.  I flushed it out and filled it with gas immediately but it still rusted...     Thanks for the advice!

[patpollin]

Just a comment on your gas tank issue.  When you use an acid to clean the tank follow it with a rinse of water and baking soda to neutralize the acid.  Rinse this out with water and then a rinse with denatured alcohol to get the residual water out. Next either fill it with gas or give it a coat of tranny fluid if you will not be using it or awhile. I did this and not even a trace of flash rust.

I just did a moped tank just like this also, only I added 20 minutes of hair dryer after the alcohol rinse until I saw no more liquid in the crevices of the tank to really get rid of the alcohol and water residing in any pores of the metal.  since there is no water present during this stage there shouldn't be any flash rusting either.  after that I coated the tank with marvel mystery oil, then added gas.