First XS650, yep I'm the new guy.

[nj1639]

- i can easily get my carbs on and off without removing the cam chain tensioner cover, nor do i remove the rubber boots...the allen key screws for the tops and the bowls are a good move

Next time I have to take them out I'll try taking the top link plate off and give that a go, sounds easy enough 'specially with the allen heads in.

 

[dpawl31]

Thanks guys.

Well, I threw my old XJ plate on her and hit the road yesterday...

Battery is sitting @ 12.45v before and after the 40 mile ride.
Haven't checked what it's running while the motor is running. I have a digital voltage meter I will be attaching to the gauges in a few days to watch it while I drive.

Anyway, ride went with catastrophe. However my horn and blinkers now do not work at all. That might be from me removing the 'ghetto wire' the PO had running from the low beam to the 'lights' fuse? I know I need to go through ALL connections and clean, but wondering if anyone has any tips on where to start? I have new LED blinkers coming in about a week. I need to find the flasher relay... is that the one on the right hand side under the tank, three prong? Because my new electronic flasher is 2 prong...?

Brake light is either always on or off, not sure which. I think the rear brake sensor is faulty, the PO has duct tape around it. If I remove that for now, which way is to disable the switch - wired together, or apart?

Now, for the running part... ran pretty damn good, great power when I got on it.
Idles smooth, and even idles decent after only about 30 seconds of 1/2 choke.
EVERY time I decelerate... pop pop pop... backfires like mad. Ideas? Too rich? Hell, I kind of like it... but if somethings wrong, I should fix it.

Every so often when I get on it, it misses a bit. Very rarely. Electronics issue? Loose connection? Or lack of fuel in bowl?

There are no carb settings for mixture aside from the pilot circuit correct? I mean other than sync?

Any tips would be appreciated! I work 80 hours a week and don't have a lot of time to 'look into' the problems deeply. I really only get the time to fix them, lol.

 

[MercKing]

Dpawl, you the guy that called me about a mirror yesterday? Welcome! i'm new to the board too. My XS does not run at all, I'm jealous.

 

[dpawl31]

lmfao! That's awesome! Well, not the no-running part lol.

If you want help let me know! I did a LOT of work on my XJ!

 

[danxs650mass]

any of you nh guys going too bike week??

 

[XSLeo]

Flasher is under tank, three wires, Brown, brown/white, black, The two prong flasher will plug in the same place, use the brown and brown white. The black wire goes to the canceler.
As far as checking and cleaning the connections, start at the tail tight and work forward. When you run out of connections your done.
Brake lights come when switches make contact, so hooking the switch wires together will make lights on all the time. Need a switch I got one.
Your missing can be carb or ignition.
I would check the carbs for crud in the float bowls. probably clean them too, paying particular attention to the idle and enrichener/ choke passages. Very small holes need to be clean.
Ignition needs proper voltage to work right, low voltage can cause erratic spark and low to no advance.
12.45 before and after a 40 minute ride indicates low or no charging. Check battery voltage running. 12.5 to 13.5 at idle is ok. Rev the engine up, 2000 rpm should read 14.5 volts. At higher rpms, 5000 it should be 14.5, no higher. If the voltages are low then you need to check the charging system.
The low voltage/ no charge will keep the turn signals from flashing. And the horn won't work so good either.
Carb mixture is set with the mix screw. Idle speed with idle speed screw, sync with sync screw. These are all external adjustments, changing jets and needles are internal settings.
80 hrs a week, you need a different job. Not enough riding time working that much.

 

[dpawl31]

Now that's the kind of help I love getting from these sites!
I'm going to go through it one at a time.

Flasher is under tank, three wires, Brown, brown/white, black, The two prong flasher will plug in the same place, use the brown and brown white. The black wire goes to the canceler. Exactly what I expected to hear, thanks for verification!
As far as checking and cleaning the connections, start at the tail tight and work forward. When you run out of connections your done. Any ideas, or just contact cleaner and a qtip?
Brake lights come when switches make contact, so hooking the switch wires together will make lights on all the time. Need a switch I got one. Thanks, now I don't have to toy with it How much for the switch shipped to 03104?
Your missing can be carb or ignition. Figured that... guess I'll start with carbs and a fresh battery.
I would check the carbs for crud in the float bowls. probably clean them too, paying particular attention to the idle and enrichener/ choke passages. Very small holes need to be clean. Ah yes, the carbs... so it begins. haha.
Ignition needs proper voltage to work right, low voltage can cause erratic spark and low to no advance. Had a feeling... seems like these old bikes LOVE to react to anything electrical.
12.45 before and after a 40 minute ride indicates low or no charging. Check battery voltage running. 12.5 to 13.5 at idle is ok. Rev the engine up, 2000 rpm should read 14.5 volts. At higher rpms, 5000 it should be 14.5, no higher. If the voltages are low then you need to check the charging system. I have a digital 'panel' that shows battery voltage, temp, time, etc... that will be mounted tomorrow night. Going to use that to monitor the battery and see what happens. Can I get a battery @ walmart to fit this? I don't plan on using electric start often if at all, I should be able to drop a walmart battery in, right?
The low voltage/ no charge will keep the turn signals from flashing. And the horn won't work so good either. Had a feeling it was related to that, my friend didn't believe me that the weak battery could cause things to not work at all. He thought they'd flash slower haha.
Carb mixture is set with the mix screw. Idle speed with idle speed screw, sync with sync screw. These are all external adjustments, changing jets and needles are internal settings. Just like my old XJ, except on two carbs this time! If the idle screw is still covered, should I bother touching it right now? I used to use a colortune plug to adjust the idle mix... you guys only tune via plug color on these bikes? I gave my colortune away with my bike
80 hrs a week, you need a different job. Not enough riding time working that much.Yes, and no. It's tough, but I own/run a family business, it's a franchised sub shop (none you guys would know, it's local, only 3 stores)
2.5 years in, and we're finally starting to see the economy come back, and get busier. If we can make it till the late fall, we pay off our equipment - which drops over $3k into our pockets monthly. That's big money to save, we'll be ok from then on out!

Thank you so much leo! Very helpful. I will keep you guys up to date.

Over time, this bike is going to receive a serious clean and polish, new style bars, new chrome switches, a different style gauge cluster or tweaking the current ones... I want to do a lacing job on the wheels, and some paint eventually on the tank, side covers, rims...

Thanks Leo!

 

[pumps]

Flasher is the big one and the canceler is the little square thing. They're sort of stuffed up under the front of the tank and coils hooked on some tabs.

 

[dpawl31]

Thanks pumps - mine is not a cylinder though?

So I got my package from MikesXS today... in it I received:
Two Air Filters
Small oil filter
new fuel line/vac line
tach cable
fuel filter

So, the tach cable was tough to get out (motor end) but finally came out. Kroiled it and installed new one.
Before I put in the air filters - we finally pulled the carbs
Airboxes out, had to remove both carb holders... then out they came. MAN were they gross! Probably the worst I have seen out of all the carbs I've done. We used two cans of cleaner, and needed more, but, hell it's midnight! Did as good a job as we could.
Eyeballed sync, left side seems open quite a bit more, but left it as is for now. Need to rebuild my baby bottle sync setup.

Completely cleaned airboxes, oil filters, and reinstalled everything.
Fuel line... well. shit. I should have measured better or something, but now I am not using my new filter, because I couldn't get it to work without kinking the line. New vac line on the petcock too.

Took a while to get it to fire, due to lack of gas in carbs. Lots of cranking and exploding exhaust lol. Once it went, ran great. Idled immediately with no choke. Fantastic.
Took it out for a quick test ride, feels a bit more powerful, but sync seems to be off now. Really shaky. It was also very cold, so who knows.

Now, the to-do list:
Oil change, inspect sump, replace filter
Electrical (more on this in a bit)
speedo bulb
install new blinkers when they come in from hong kong
adjust valves
adjust cam chain tension

1) So, as far as cam chain - I don't have the right wrench to hold the inner nut. When I turn the cap, it turns the inner nut with it. If I keep going, will that let me in to the right place without screwing something up? What is the procedure for adjusting?
2) Electrical. How do I know if its the running light on, or the brake? Hitting each brake does nothing. Always on. How do you remove the front brake sensor?
Also to do with electrical... if I am running 12.4v motor off... 13.5v motor running revved a bit... and never goes higher - is my alternator/regulator OK, I just have a crappy battery? How do I clean the alternator?

Thanks for the help guys... hoping I am almost there... Can't believe this thing fires one kick and idles no choke, on a 50 degree night... For $300 so far!

 

[pumps]

Manual.
http://www.knucklebusterinc.com/tech/XS650.pdf
You should put your model year in your signature to make things easier. On my 77 under the seat going over the fender are the wires to the tail/brake light . seems there is a blue and a yellow and a black. I'm thinking yellow goes to the brake and blue to the tail/running light. Black is ground. Maybe the brake light filament is just out? Get out your meter.

 

[dpawl31]

Thanks again Pumps.

It's an 81 just FYI, I will adjust my signature in a bit.

I have to go through ALL the wiring connections for sure.

So - if my voltage sits @ 12.4 w/ motor off, and 13.5 w/ motor running over 2k...

Is it safe to say my alternator/regulator is ok and I just need a new battery? Remember, my battery was nearly dry when I bought the bike, been stored for over a year that way. Right now I have it topped off with distilled and it's holding 12.4v but doesn't seem to go over 13.5 while running. But the bike runs fantastic, the headlight/tail work as well as dash. But no blinkers or brake. (connections more than likely)

 

[XSLeo]

Your running voltage is a bit low. It could be your battery.
I would do a few checks before I started spending money.
It could also be your brushes.
It may even be a bit to much voltage drop between the battery and brown wire at the brushes.
Compare The battery voltage to the voltage at the brown wire at the brushes, the voltage should be very close. Even a 1/4 volt can be to much drop. 1/10 is better.
If voltage drop is to much, check the connections in the plug where the alternator plugs into the harness. The key switch can also be a problem, it can be taken apart and cleaned. Bright shiny contacts.
On your blinkers, connections in the wires and switches can be problematic. The blinkers with the stock flasher needs all the bulbs to be 27 watts, any less they will light but not flash.
Ckeck to see if all the bulbs are good and the same wattage. Check the grounds.