Bike not starting

[GSQC]

My problem is as simple as complicated for me , Bike was running 3 months ago , now that I tried ty start it again it won't.

Fully charged the battery and try to crank it with starter (it spinning but not firing), with the kick the same result cheked the wires one by one with a test light four are not giving any sign of life.

I arrived to the conclusion that electricity do not reach the coils and it's the reason that it has no spark on any of the four cylinders, do you have and idea what could be the reason?

sorry for the mistakes, my english is not that great.

Any help with be hugely appreciated!

[spyug]

Well it seems that you have diagnosed the reason it won't start i.e. no spark so now we have to back track a bit. I am not fully familar with the 1977 750s but it has a "points" ignition which controls the coils which send the spark. Since there is no spark, the breakdown is somewhere between the coils and points or before the points themselves.

First off, with any electrical problem it is a good practice to make sure your fuses are all ok so check them.

The battery is good and it will spin the starter so we won't worry about that.

It is very unlikely that the coils themselves have both given up the ghost at the same time so I'd forget about them for now.

What we need to concentrate on are the points themselves and the electricity getting to them from the battery.

Do you know when the points were last changed? They will wear out over time and need to be replaced to function correctly. You should take a look at them and referring to the manual verify if they are still viable. Often the point faces become "corroded' and need a clean up with sandpaper or a points file to function so you could try that.

There will be some testing information in the manual too to check that voltage is getting to the points and from them to the coils so you will want to check those as well.

I am thinking that it is the points so have a close look at those and let us know what you find.

Good luck with it.
Spyug

[BassCliff]

Hi,

See if these help...

Diagnosing Slow Cranking
Igniter/Signal Generator/Coil Test
Igniter Repair/Testing (2MB PDF)


Thank you for your indulgence,

BassCliff

[Redman]

...
.....
I arrived to the conclusion that electricity do not reach the coils and it's the reason that it has no spark on any of the four cylinders, do you have and idea what could be the reason?
..

DO you have a voltmeter?

If you have a volt meter you could check to see if have voltage to the coils.

Your english is just as good as some of the others on here (and your spelling better than mine sometimes).

Tell us more what you find.

You are 17 years old?

Dave

[lucabond]

Are you pulling in the clutch handle ? If it hasn't been disabled the bike wont start without pulling it in. Good luck

[Octain]

I'd check to see if the plugs are getting fire. To do this, just pull one of the plugs. Replace pulled plug to the ignition wire and lay it on the head. Do not hold it or thouch it. Hit the start button and look to see if the plug is shooting a spark.

[GSQC]

I just turned 18 not long ago, as for the kill switch or clutch handle always cheked them before any attempt on starting the bike!

I have a test light , and I am suppose to buy a voltmeter this week so I can start runing the major cheks that bassCliff posted.

As for voltage to the coils they are maybe getting some voltage but too weak to reach any of the plugs

If the points are my problem can I change them to electronic ingintion ?

[spyug]

If the points are my problem can I change them to electronic ingintion ?

I believe you can go with the Dynatek "S" ignition or Boyer Bransden has one too. Look up their websites and read over the info. Not cheap but a good reliable fix to the issue of points.

I hope you can sort it out without having to shell out the big bucks.

Good luck with it.
Spyug