A week out in the rain has made my XJ run better?

Hi guys, I posted last year about my XJ550. I've since cleaned the carbs and did some other work, and have otherwise been happy with it.

My garage is being rebuilt, so I had to keep my bike on my front walk. I didn't ride it for about a week, and it weathered two storms, uncovered.

Today I went for a ride, and it was noticeably... better.

The first thing I noticed was that the exhaust note was different. It was a little quieter, and seemed to sound more like a typical small displacement inline 4. Before, it had kind of an odd note to it.

Before, between about 5k and 6k rpm, I had a rather annoying buzz, and this has almost completely subdued. Above 7k the engine practically sings; barely any vibrations whatsoever. Throttle response is better, and the engine braking isn't quite as harsh as before; engine braking is much quieter as well. Accelerates a bit more quickly. Everything is 'smoother,' as it were. Additionally, fuel mileage improved. Went from high 40s to mid 50s, primarily cruising around 60mph on county roads.

The only thing I can think of is that the rain affected... something. Perhaps I was having a partial miss? Weak spark? Ignition module issues? But if it was due to the rain, I'd think the 'fix' would regress as things dried, but that has not been the case.

I did a plug chop, and everything is a healthy tan from 3k to 8k.
Checked all the connectors everywhere, and there was/is no sign of water getting on the ignition bits, excluding spark plug wires.

I know this is really crazy, but if anyone has the slightest idea as to what is going on, I'd really appreciate it.

 

someone switched your bike

 

Wouldn't surprise me. I'm really baffled. I even had a small fall (due to me not noticing sand at an intersection, stupid me) and it still ran great. I guess I should be thankful?

 

my vote is the TCI. congradulations anyway! since they don't break the pocket, personally I'd pick one up for a quick swap once it goes back to the way it was, cause it will, sorry but it probably will, well I hope not of course, but it will lol. since nothing mechanical Could have changed, I beleive the TCI is most vulnorable to the moisture factor.

 

Agreed. Either that or the air filter is half waterlogged, and effectively "de-tuned" the bike, smoothing it out.

Might want to be sure the air filter is dry...

 

obviously it was thirsty, mine like a little scotch in their water

 

I remember there being a thread about rebuilding the CDI box, but I can't for the life of me find it.

Spare boxes on e-bay seem to be about $60, then rebuild mine as a little project.

 

Let me know if you find it! thnx

 

In a similar case of WTF?, my exhaust collector rattle went away the last time I washed my bike. Not expecting that 'fix' to last, but I'm enjoying it while it does. I chalk it up to something my dad calls P.F.M.

 

Thought it was being "Punished" and decided to behave?

The baby MAX seems to act better if openly discuss the idea of getting a newer bike

 

That's pretty odd, mine is always out uncovered in every storm, every bit of snow/hail/rain due to living in an apartment and having a lack of a garage, the only thing it "rarely but sometimes" does after a heavy rain, is bog down exactly at 6k RPM, the tachometer will climb to 6k RPM then instantly hit 0RPM and it'll have a really low bogging out sound until I quit giving it throttle, then it'll go strait back to 6k and from there climb up to 12K and never give me that issue again until the next time it sits out in the rain. (btw, anyone know why it does this? It's not really a bother since it's so rare and only happens after it rains or below freezing temps, but I'd still love to know.)

Sounds to me like that storm did a service to your carburetors. But in any case if there's water that freed something up, I'd find it and make sure it's cleaned out and re-lubricated.