Jump to content
Sign in to follow this  

Yamaha Yz80 wont start after rebuild?

Recommended Posts

So I just did a rebuild on my 98 Yz80, and it wont start. At first, we put the gaskets on wrong, so coolant was leaking everywhere. After we fixed that, and put everything back into place again, piston went up and down smoothly, and it has great compression. The problem is, it does not want to start. Im not really sure what to do, because before, my compression was very low, so I did a rebuild, but now it still does not start. So I need help.

Share this post


Link to post
Share on other sites

I checked the gas, I cleaned the carb just to be sure, i havent had the chance to start it up yet, but im pretty sure it wont fire up. It doesen't seem like im getting spark, the air filter is clean, I tested the spark, and i cant see anything igniting, and it is a brand new spark plug. So what could I do to get spark?

 

 

Share this post


Link to post
Share on other sites

Could it be my Ignition coil possibly? Or would it be my whole cdi box? The Cdi Box wobbles a little, and it got a little wet.

Share this post


Link to post
Share on other sites
Could it be my Ignition coil possibly? Or would it be my whole cdi box? The Cdi Box wobbles a little, and it got a little wet.

I rebuilt my my yz125 a couple of months ago check to see if the kill switch is hooked up in the right sequence. Also check the ground. It should start right up with s couple of blips of the throttle without the choke on

Share this post


Link to post
Share on other sites
On 6/23/2017 at 9:36 PM, cameron_yz80 said:

I checked the gas, I cleaned the carb just to be sure, i havent had the chance to start it up yet, but im pretty sure it wont fire up. It doesen't seem like im getting spark, the air filter is clean, I tested the spark, and i cant see anything igniting, and it is a brand new spark plug. So what could I do to get spark?

 

 

You need a little brother you can con into sticking his finger into the plug socket while you are kicking it.  Then you will know if you are getting spark or not.

 

P.S. He as to hang onto the bike with his other hand for this detection method to work.

Edited by GlennRay
  • Like 1

Share this post


Link to post
Share on other sites
You need a little brother you can con into sticking his finger into the plug socket while you are kicking it.  Then you will know if you are getting spark or not.

Or you can hold the spark plug next to something metal while you give it a couple of kicks. This way saves your family money on medical costs.
  • Like 1

Share this post


Link to post
Share on other sites

Holding the spark plug against the head while cranking the engine is the correct way to check for spark.  The little brother method only works once.

  • Like 2

Share this post


Link to post
Share on other sites

Also, How do you say if the kill switch is on right? The brand new kill switch I put on, the two electrical wire things plug into a green one, and this other one, they both fit snug into them

Share this post


Link to post
Share on other sites

I just unplugged the kill switch and tried starting, and it still doesen't start? I really wanna get this bike running!!!!!! Its been such a long time since ive rode!

Share this post


Link to post
Share on other sites

Start with the simple things and check the grounding first.  If the stator or the ignition coil aren't properly grounded no voltage or sparks will be produced.  Leave the kill switch out of the picture until you have resolved the spark issue.

Share this post


Link to post
Share on other sites

If I remember correctly there is a ground wire from the ignition coil that gets connected under one of the coils mounting bolts.  That surface needs to be clean and free of rust and paint.  I also think there is a ground wire from the stator assembly to a bolt that ties it to the frame of the motorcycle.  This connection also needs to be clean and free of rust and paint.  The frame of your motorcycle is the electrical systems ground.  Good luck, I hope it is the ignition coil because as you said it is cheap and easy to fix.

Share this post


Link to post
Share on other sites
19 hours ago, Four square T said:

Before you go out buying a new CDI or stater if you have a multi meter check for continuity

Finally.

  • Like 1

Share this post


Link to post
Share on other sites

Check the continuity of the ignition coil as well as the continuity of the stator plate.

Share this post


Link to post
Share on other sites

Good news, it didn't have anything to do with electrical, all I had to do was tighten the metal thing on the spark, I did my break in today, of course I let it warm up for 15 minutes, and even in the low end it was very boggy, like there's no throttle response and wants to bog out. I'm running 50:1, is that to lean? Is that my problem?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...