Bike won't start :-( everything appears in order

[Myke Nytemare]

So, its been a while since I had a chance to ride my 78 XS400.
I had completely rebuilt the carbs earlier this year, put them on, and had the bike running ok and even test rode it. But....the floats were slightly off and I was getting fuel in the crankcase. I quickly took the carbs off, drained them/opened them up and the carbs/bike sat off for the last 4 or 5 months.

Today, I finally get out to the garage, new ethanol-free fuel in the tank, get the floats set up and carbs on, everything including the hoses/vacuum lines and air filters back on. The battery was on a tender and everything lights up when I turn the key...BUT NOTHING HAPPENS WHEN I KICK IT OVER :-( it even feels like there is less resistance in the pedal than I remember :-/

I messed with the rear wheel position several times to ensure I was really in Neutral (actually getting a click down for 1 and a slight up for N), the clutch is actually engaged/adjusted, the throttle side switch is set to run, and have clear fuel lines to see there is fuel and I primed the carbs.

Is it possible the ignition system just took a cr@p? Any help would be appreciated.

 

[xschris]

Did you completely drain all the old oil with gas in it out of the motor? That also includes the sump. Also did you replace the spark plugs? After those have been addressed I work check to make sure you have spark at the plugs. If you still have issue make sure the battery is at least putting out 12.5v at rest. If you still have no spark check the points and timing to make sure that is where it needs to be. If you feel like the compression is off do a dry then wet test to see where you are at. All the specks for these are in the manual.

 

[Myke Nytemare]

Oil completely drained and battery putting out close to 12.8v.
Forgot the plugs....ugh....just looked and they were black. Will change later today and see where I am at....if that doesnt work I may buy the PMA conversion.

Thanks and will update tomorrow.

 

[xschris]

Why a pma? That's for the charging system and as far as I know they don't make a kit for the sohc xs400.

 

[Myke Nytemare]

Well, a PMA http://xs400ignition.com/ as the points system is not something I am super familiar with and I figured I could eliminate a problem area including the timing/ignition &spark strength/charging...which it appears I have as the bike was running a few months ago and now I have NO SPARK.

Ill try to check the points and see if I can troubleshoot as to what happened.

 

[xschris]

Ok, that's a pamco. A pma is a Permanent Magnet Alternator. Which our bikes do not have.

 

[Myke Nytemare]

my bad.....have to adjust/clean/repair the points in the next few day sand see if I can get spark.

Let me see if I get anywhere :-(

UPDATE:
Rotated engine and it appears the left point is frozen (as the right one moves). I will disassemble and clean and try to follow the manual to get it running again....cant believe it froze up from sitting.

If I can't salvage it I will get a PAMCO as it looks like points/condensor go for $70 or so on their own and id rather install a completely new part and upgrade so I hopefully do not have this issue again in the future :-/

 

[Myke Nytemare]

Did you completely drain all the old oil with gas in it out of the motor? That also includes the sump. Also did you replace the spark plugs? After those have been addressed I work check to make sure you have spark at the plugs. If you still have issue make sure the battery is at least putting out 12.5v at rest. If you still have no spark check the points and timing to make sure that is where it needs to be. If you feel like the compression is off do a dry then wet test to see where you are at. All the specks for these are in the manual.

So, now I am more confused. I used a test light to check the static timing and the left and right points are powered up at and around the respective LF and RF marks. and also the stator is definitely functional as feel the magnetic pull on my socket wrench when turning over the bike manually while the ignition in "on". The headlight powers up as well as my indicators and the battery is very good at over 12.8 volts.
The dry compression looks about 140 on one side and 150 on the other so I think everything is relatively ok.

There is no spark at the new plugs....
Could this be a coil/condensor issue? PLEASE HELP!!!! THANKS!

 

[xschris]

If your plugs, points coils all test good I would check the run/off toggle. Make sure the contacts in the switch are clean. There is also a ignition fuse to check if you have not already done so. Look over the manual and make sure the bike is wired like it should be. Remember you have a 77-D model. Other years are a bit different.

 

[Myke Nytemare]

If your plugs, points coils all test good I would check the run/off toggle. Make sure the contacts in the switch are clean. There is also a ignition fuse to check if you have not already done so. Look over the manual and make sure the bike is wired like it should be. Remember you have a 77-D model. Other years are a bit different.

Thank you...switch was replaced with ebay unit as previous one cracked off...didnt even think of the switch being bad...and forgot about the fuses as they were fine a few months back...I think I am slipping

 

[Myke Nytemare]

SO, the switch wasnt actually cycling off the motorcycle in the "off" position....each of the three spots appears "on".
The switch did crack off and break....so now I must buy a run switch assembly/housing.
My only question is with the 2 exposed "run switch" wires, the indicators and headlight are on whether I leave them separate or connect them together. Seems like the harness may be grounded out somewhere or something. :-(

 

[Myke Nytemare]

SO, the switch wasnt actually cycling off the motorcycle in the "off" position....each of the three spots appears "on".
The switch did crack off and break....so now I must buy a run switch assembly/housing.
My only question is with the 2 exposed "run switch" wires, the indicators and headlight are on whether I leave them separate or connect them together. Seems like the harness may be grounded out somewhere or something. :-(

Still need some help with this...anyone know how the right controls should be wired or operate?