I did something stupid...

My new (to me, at least) 1982 xj550 tends to flood easily - I got caught in that rescent heavy rain/wind storm that hit Toronto last Saturday, I took shelter in a parking garage for an hour or so, decided that I'd better just try and make it home. The bike did start, took some coaxing, and it made it home, though it sputtered and complained the whole way, it felt like the engine was losing power, misfiring - I had to keep the engine reving high to keep it running.

Anyway, my bike hasn't started since - When turning over, there's an obvious smell of gas, and some gas drips from the pipes. I pulled the plugs, let them dry out, but my battery was quickly run down. I bought a battery booster to help start the bike - and here I did something stupid - even though I went over all the steps in my head, somehow I still put the red to the black - arrgh. I blew a fuse - hopefully that's all the harm I did. The battery booster still works, and tomorrow, I'll buy a fuse and see if my electrical system still works.

I don't expect anyone else has done something this obviously stupid before, and hopefully I will never again, but is there any chance that I still have a battery, or will I need a new one?

Also, I expect I need to tune my carbs (waiting on a Clymer manual to help with this) but is there any other reason my bike seems to have problems when it's raining (even when it's in the garage out of the rain)?

Third - I'm wondering about the flooding. When you park the bike, where should the petcock be pointed? (yes I'm new to biking!) I've read that the gas tank should be turned off to prevent fuel form constantly running into the carbs while the bike is off, but the xj550 has only 3 petcock settings; reserve, main tank and prime... should I just leave it on the main tank? Is this potentially why my engine seems to flood easily (after having run and then after having sat for a time)?

Thanks!

 

The rain problem is more likely cracked coils that don't like the ambient moisture than a carb problem.

The battery's probably fine, but, depending on how much back-current you fed it, you may have blown the regulator/rectifier.

Petcock should be set to main tank during normal riding.

Cheers,
Paul

 

I've had a ton of these bikes and I just did the exact same thing, flip flopped positive and negative....until I saw smoke...thankfully I go to it in time...no damage. Glad to know I'm not the only one. I've only been working on bikes for 12 years now...... :roll:

 

Hi Steve,

I'll try to answer about the petcock. (Sorry but English is not my first language)

Your petcock must be always on "main tank" and this should cause no problems BUT it's always possible a failure of the internal rubber membrane.

You can do a quick test simply disconnecting the fuel line, if gasoline is dropping, looks like is time to get a new one or rebuild it.

If i'm not wrong, Chacal (look in the "sell, trade, swap" section)should have a rebuild kit for petcocks.

 

first thing Steve is dont beat yourself up about getting the cables backwards. everyone has done it atleast once if they have worked on anything with a battery. I agree with SQLGUY it sounds like a cracked coil. My old honda 750 had a cracked coil pack and I didnt know it until i washed it one day wont start a week later i figured out it was the coil pack.

 

Could be bad wires.

A common method to checking automotive wires is to open your hood, start your car, and take a spray bottle/hose on light shower to your wires. If you have a bad set of wires, the car will run rough or stall. What happens is that the rubber coating eventually gets breaks in it large enough to allow your spark to find an alternate path, and the water assists with it.

Start her up, and take a spray bottle to your components. Just regular tap water, nothing fancy. Should be able to isolate it pretty quick if that's the case.

The actual way to test your wires is with a DVOM (Digital Volt Ohm Meter) or multimeter. You can test the resistance of the wires pretty easily if you have access to one and you know what the spec is supposed to be.

 

Make sure you have a good one, many times your meter will read 0 or no continuity. You essentially need to make it more sensitive, by reading /10's or /100's. Not sure if some models do this automatically, but mine does not.

I couldn't figure out why new wires had no continuity.

good luck

 

I would say this is your problem.
If your petcock is working properly and in the Main tank position, gas won't flow until you crank it over.
No drips until you start her sounds like it is working properly.
Drips after starting sounds like your needles aren't seating correctly or floats are set to high.
Which brings us back to the above quote.

 

Thanks for the advice... I boosted the battery with the new fuse put in, and got it started. Still, the engine runs rough for the first while, cylinder 2 and 4 seem to backfire and I'm sure the carbs are running too rich... so it makes the bike prone to stalling, and then flooding, for the first little while - in fact, I need to play with the choke until I find the sweet spot to keep the engine going, for at least 5 minutes... sometimes more. After it's running smoothly, though, it sounds good, and it idles well at about 1500rpm's with the choke all the way off. But after riding for an hour or so, the idle is high, about 2000-2500 rpm's, and this is baffeling me (as well as burning my gas) Someone told me that it might be my throttle doesn't have enough free play, I'm wondering if it is a symptom of my carbs that need to be tuned/balanced (2 and 4, I'm pretty sure run too rich...)

 

there are 2 tubes running to te petcock the bottom one is for fuel to go to the carbs the top one is a vacume tube when in reserve or main there is a diaphram inside the petcock that keeps it closed until you start the bike then the vacume from the motor pulls the diaphram open and allows gas to flow the prime setting bypasses this diaphram it is used when you tune the bike


the fuel then runs into the bottom of the carbs (the bowls) where it is pulled out by syphonage from air running through in the bowls are floats with needles when they are at the right height the needles sit against a seat and stop excess gas from flowing into the carbs if the float is set to low you dont get enough gas and you get power loss if they are too high you get flooding and gas will flow out of the airbox and into the engine

it sounds like you need to read up on carb cleaning, float adjusting and, bench syncing this will solve most of your problems

start with this thread ----- Clean Your Own Carb's - The Whole 9 Yards - by: Rick Massey