1977 no spark

[brok13]

everything stock I recently broke the bike down to rebuild , hooked all the wiring harnest's up plugged back in the coils , no spark. I have tested the coils and get 4.5 and 9.5 on the secondary .. I have also found power going to each coil . Could it be the condenser ? Oh yeah also the points look good as well no corosion. any ideas?

 

[brok13]

Ok any suggestions would be appreciated. When I put a full charge on the battery and jump start the starter relay I get spark from the points for a minute then nothing . Also I noticed the battery drops to 9.5 -10 v with the starter going is that normal ?

 

[xschris]

If the condenser, points, plugs and caps are old I would replace them so they can be ruled out. There should not be sparks between the points. If so that would be a bad condenser. Then make sure the points are gapped to spec and the bike is static timed. Did you paint the frame? If so I would check all the grounding points on the bike including the condenser, that should also be grounded where it mounts. A drop in power on the battery is normal when using the starter but the battery should not be wiped out after a few cranks of the motor. You could have a dead cell in it.

 

[brok13]

I tested the coils getting 4.5 on primary and 9.5 on the secondary, it ran before I took it apart and when I did take it apart I left the coils and condenser exactly where they were. It will crank for a couple minutes then will stall out . Could my battery be bad since it's dropping below 10 under a load ? The battery doesn't completely die just drops lower and lower each time I'am trying to crank it .

 

[brok13]

@ xschris , so when you have the points cover off and your trying to start it there shouldn't be any little spark on the point ? Sorry I have an xs650 with kick only and a Pamco this points and electric start are a new world for me

 

[xschris]

If it is sparking the gap could be off and or the condenser is bad. Try another battery and see if that helps. Pamco does not make a setup for the xs400's with points.

 

[brok13]

Alright I will that a shot xschris. I was mentioning the Pamco just saying that's what I run on my xs650 ... This is a project 400 I got so points and electric start are a whole new thing for me

 

[xschris]

Also try using the kick start so not to drain the battery.

 

[brok13]

Ok so on a full charge 13.3 volts I cranked the bike over , one cylinder is firing . When I look at the points the little tiny spark between the points only one side has the little spark and then when I go ahead and I swap the coils over and try to crank it up that way I get smart to the other one and not the one that I just had it on and a really bad back fire off the cylinder that wasn't firing . Bad coil ?f

 

[xschris]

If you swap only the wires at the plugs it will through off the timing 180* and that will cause the backfire. You would have to removed the wires at the harness and physically move the coils to opposite sides. If both coils test within spec and the plug wires and caps are good the only other thing would be points and condenser. Make sure the plug wires are making a good connection to the caps by cutting off a small bit of the ends of each wire.

 

[pamcopete]

If it is sparking the gap could be off and or the condenser is bad. Try another battery and see if that helps. Pamco does not make a setup for the xs400's with points.

Well, yes, he does! www.xs400ignition.com Also available from www.mikesxs.com

 

[xschris]

I meant to say, " pamco does now make a setup for the xs400's with points". Sorry it was a typo