E Start vs Kick start

[cap44]

and here is my problem: I just picked up a beautiful 1976 cafe racer style. I have installed an new battery and redone and set up the carbs, check points and timing but the bike would just not start. Pulled plugs and had virtually zero spark when rolling it over with electric start. When I kick it over it seems to have a very reasonable spark! My problem is that I have recently had a right knee replacement so kicking it over is a problem. So I need to be able to start this bike on the electric starter! So where do I go from here?
-find a higher cranking amp battery?
-rebuild the starter so it doesn't draw so much current?
-electronic ignition?
-what else is there?

 

[Its been a long time]

Ignition depends on battery voltage. E start is pulling the volts down when cranking. Hence weak spark. Could be worth having the battery load tested, new doesn't always mean good.

It's charging? Charging system needs to be top notch.

Yes, I advocate for electronic ignition. Not everyone does.

 

[RC4MAN]

Welcome, hope you get it sorted out. Pictures?????? We love to see bikes.

 

[cap44]

Here she is: 1976 XS650

 

[Max Midnight]

My problem is that I have recently had a right knee replacement so kicking it over is a problem.

Whilst you have an issue with your electric leg don't give up on your (refurbished) OE one.
I've had both replaced (and a hip revision) and if my experience is in anyway typical then it will take time to settle down.
Keep doing the exercises you've been given and slowly your knee will emerge from the swelling and eventually you will forget you have a new hinge.

 

[Wingedwheel]

With the key on check voltage at the coil. You shouldn’t get more than a slight drop from the battery to the coils. If voltage at the coils is less than 12v before hitting the starter it’s not enough. Probably need to clean the switch and connections.

 

[Highpower]

You probably have a marginal battery. Charge it overnight and do a load test on it.

 

[cap44]

and here is my problem: I just picked up a beautiful 1976 cafe racer style. I have installed an new battery and redone and set up the carbs, check points and timing but the bike would just not start. Pulled plugs and had virtually zero spark when rolling it over with electric start. When I kick it over it seems to have a very reasonable spark! My problem is that I have recently had a right knee replacement so kicking it over is a problem. So I need to be able to start this bike on the electric starter! So where do I go from here?
-find a higher cranking amp battery?
-rebuild the starter so it doesn't draw so much current?
-electronic ignition?
-what else is there?

 

[cap44]

Important Update: measured current with my clamp-on ammeter and the starter is drawing 8.6 amps. That looks OK right????

 

[bazz]

What ignition does the bike have?
If it's electronic which electronic?

 

[Its been a long time]

Important Update: measured current with my clamp-on ammeter and the starter is drawing 8.6 amps. That looks OK right????

No that doesn't look right at all for a healthy starter motor. Here's the Yamaha manual specs -

 

[cap44]

What ignition does the bike have?
If it's electronic which electronic?

points ignition

 

[cap44]

points ignition and these are my coils. Measured resistance and goy coil 1: Primary 5.5 and secondary 9.72: coil 2 Primary 7.4 and secondary 9.28

 

[Highpower]

I’m going to beat on this horse again. Before you go chasing your tail around, charge your battery overnight and check it with a load tester.

A healthy, fully charged battery should hold no less than 10.8 volts for 10 seconds. A marginal battery will go below that and possibly still be usable down to 10 volts under load. Any less than that and it is no good and needs to be replaced for reliable operation.

Your charging system should be putting somewhere between 13.5 and 14.5 volts into your battery at engine rpm’s above 2000. XS systems are sort of marginal so I may be off a bit on engine speed, but even my ‘68 Triumph with it’s all original ancient charging system does that.

 

[cap44]

It is a brand ew battery that I have tested with my own load tester that says it is good. I work at a car parts store and we have a professional load tester there that I will use when I go back to work next week

 

[Highpower]

It is a brand ew battery that I have tested with my own load tester that says it is good. I work at a car parts store and we have a professional load tester there that I will use when I go back to work next week

I'm sorry for being so pedantic about it, but I have seen many times where someone starts in the middle of the diagnostic procedure instead of at the beginning. The fact that you have a new battery is an excellent start to figuring this out. Test it anyway just to make sure, but it does sound like it could be the starter.

But first:

Check the charging system to make sure that it is working properly. If that is up to snuff, the next thing I would do is to inspect the battery ground wire and make sure that it is properly grounded. Then check the wire that leads from the battery to the solenoid and the one from the solenoid to the starter, maybe even hook up a new (different) one temporarily and see if the current draw changes. Many, many times these issues can be traced to poor connections, either loose wires or corrosion. Sometimes the wires may show continuity, but because of damage, they won't carry sufficient current.

Back in the late 1970's when I was still in the motorcycle business working as a mechanic, I had that very issue come up with an ignition wire that had broken most of the strands inside of the housing. I couldn't see any damage, but the bike wouldn't run even though it showed 11.8 volts coming out of the wire. It took me the better part of a day to find that sucker. It had voltage, but couldn't flow sufficient amperage to fire the points

While it could certainly be the starter, I would always suspect the electrical system up stream of it first, before I remove one and take it apart. Fortunately starters are easy to remove and not terribly expensive.

 

[gggGary]

As a test; jumper from battery to coil red, then try the starter?
If the starter is turning the motor over with good speed I think we can move to the power to coils side of the equation. key switch, kill switch, wire connectors, all potential voltage/current thieves. All are due for general maintenance anyways.
Keep in mind coil power includes the ground circuits.
The factory harness uses a ground connection from engine to the top engine mount where the condensers mount.
If you haven't; remove, clean, check the ground strap from battery to frame, they are often trouble spots with internal corrosion 40 years on.
Also for testing, trouble shooting, remove the plugs from the engine. ground them and do your track down testing.
When working on old equipment rather than chasing a "problem" systematically go through and confirm proper operation of everything involved, it's a technique that often leads to trouble free operation with less roadside grief.
Those are kind of odd coils for an XS. secondary should read in K ohms is M?L 10,000 ohms. check coil wires plug caps and or spark plugs for proper ohms also. Factory caps were in the 9K ohm range, failure not unusual. 5K replacements OR resister plugs (NGK 5122 Spark Plug - BR7ES) acceptable alternatives.

 

[Grimly]

If it was a total strip-down and repaint frame-up rebuild into a cafe, there might be paint under the grounding screws, preventing a good connection.
Not the first time that's happened.

 

[jetmechmarty]

When working on old equipment rather than chasing a "problem" systematically go through and confirm proper operation of everything involved, it's a technique that often leads to trouble free operation with less roadside grief.

As you’re troubleshooting consider that corrosion may exist in the electrical system. That includes the ignition switch and wire harness connections. Compare your battery voltage to the voltage at the coils. Ideally, they should be the same. Low voltage at the coils is not uncommon for Yamahas of this vintage. My own XS650SK does not start with the electric foot when cold. It starts on the first kick even if sitting for a month or more. I’m considering replacing my main harness at this point.
Checking voltage at the coils should be among your beginning troubleshooting tasks.

 

[Jim]

Important Update: measured current with my clamp-on ammeter and the starter is drawing 8.6 amps. That looks OK right????

No that doesn't look right at all for a healthy starter motor. Here's the Yamaha manual specs -

View attachment 353202

Yeah, Like IBALT says, that's not right. The starters specs are cast into the starter end cap... .5kw at 12v. So if we divide 500 by 12, we get 41.666 amps.
Pulling only 8.6A points to high resistance somewhere.
I think the first thing I'd do is pull the boot off the power cable at the starter. This is what I found on mine (yellow circle). Power cable severely corroded.
It could also be the brushes contaminated with oil (failed seal).
Could also be high resistance in the solenoid. You can use pliers or such to jump around the solenoid to troubleshoot.
And it could be either cable from the battery to the solenoid or from the solenoid to the starter.

But... like IBALT says, that current draw is way too low.