Honda ATV Forum banner

1 - 20 of 29 Posts

·
Registered
Joined
·
2,810 Posts
Discussion Starter #1
No spark help

I'm stuck on finding my problem..

On a 86 trx125 I'm getting no spark.. I'm 99.9% sure it's not the CDI. I've checked it with 2..

OHMed everything out and here's what I've got.


Manual says

Primary coil: 0.18+or-0.2 I'm getting .3

Secondary coil: 4.1+or-0.4 kohms I'm getting 4.348

Exciter coil: 100-400 ohms. I'm getting 303.9


Pulse generator: 90 ohms. I'm getting 93.5

What am I missing??


Stator ohms good





Sent from my iPhone using Tapatalk
 

·
Super Moderator
Joined
·
38,518 Posts
pull the spark plug boot off, lay just the wire on the engine, crank it over, get spark then ?. I know some Hondas use a resister in the spark plug boot.
 
  • Like
Reactions: cmanningjr

·
Registered
Joined
·
2,924 Posts
Hi: Also do you have a Neutral light -- do the lights work? If so unplug the Bl/W on the Ign. switch and try starting the bike.
 

·
Registered
Joined
·
2,810 Posts
Discussion Starter #4
pull the spark plug boot off, lay just the wire on the engine, crank it over, get spark then ?. I know some Hondas use a resister in the spark plug boot.


I'll give it a shot.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
2,810 Posts
Discussion Starter #5
Hi: Also do you have a Neutral light -- do the lights work? If so unplug the Bl/W on the Ign. switch and try starting the bike.


Yeah, all the lights work.. I've got something that's went bad. Just can't find where..

I'm thinking the coil...


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
2,924 Posts
Did you unplug the Bl/W wire? -- if so place a jumper wire in along side of the green wire on the Ign. coil and the other end of the jumper on neg. of battery -- try starting.
 

·
Registered
Joined
·
2,810 Posts
Discussion Starter #7
Did you unplug the Bl/W wire? -- if so place a jumper wire in along side of the green wire on the Ign. coil and the other end of the jumper on neg. of battery -- try starting.


Didn't have a chance today.. I'll look at it tomorrow.. 16 hr day and I'm pooped..


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
7,361 Posts
check your grounds! with all of the components checking out its gotta be a bad connection/ground issue.

also make sure your kill switch is functioning correctly.
 

·
Registered
Joined
·
2,810 Posts
Discussion Starter #9 (Edited)
pull the spark plug boot off, lay just the wire on the engine, crank it over, get spark then ?. I know some Hondas use a resister in the spark plug boot.


It sparked without the boot! Never would have thought about that...


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
2,608 Posts
Will this work? Its a resistor cap, if needed. The non resistor cap is right next to it on the Dr ATV site. Short money either way though he is a little high on shopping.

RESISTOR SPARK PLUG CAP 1/16W (23D)

Rick
 
  • Like
Reactions: cmanningjr

·
Registered
Joined
·
2,810 Posts
Discussion Starter #12
I got it to fire with one off a 300.. Is the resistor just for noise??


Sent from my iPhone using Tapatalk
 

·
Super Moderator
Joined
·
38,518 Posts
Who's got one for sale??


Sent from my iPhone using Tapatalk
can you unscrew the cap out of the boot where the spark plug goes in ?. if it has what looks like a standard screw driver slot inside the boot ?, unscrew it, check the resister under the cap :).
 

·
Super Moderator
Joined
·
38,518 Posts
or, trim about 1/4 off the coil wire, then screw the boot back on, then check for spark again with the spark plug in boot, laying on engine.
 

·
Super Moderator
Joined
·
38,518 Posts
I got it to fire with one off a 300.. Is the resistor just for noise??


Sent from my iPhone using Tapatalk
sorta, it's suppose to stop interference to electrical equipment, stupid..right ?..lol.
 

·
Registered
Joined
·
2,810 Posts
Discussion Starter #16
or, trim about 1/4 off the coil wire, then screw the boot back on, then check for spark again with the spark plug in boot, laying on engine.


Already did that.. nothing

I'll look for the screwdriver slot. I OHMed it out. One time I got around 24 ohms. I didn't see anything in the manual about reading resistance on it...so... not sure what I was looking for..




Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
2,924 Posts
Hi: Are you using a DR8ES spark plug? -- the R on the plug stands for resister plug.
 

·
Registered
Joined
·
2,810 Posts
Discussion Starter #18
Hi: Are you using a DR8ES spark plug? -- the R on the plug stands for resister plug.


Whatever the manual calls for.. I'll have to look when I get home..


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
2,608 Posts
My guess for a Honda resistor plug cap would be 5000 ohms. Yours sounds like a non resistor cap. They tend to increase in resistance with age if it is a resistor cap. I had to replace all four on my 72 Honda CB500 because they ranged from 5300 ohms all the way up to around 12,000 ohms which drove that bike's ignition system crazy. Much mo' betta' now.

Rick
 
  • Like
Reactions: cmanningjr

·
Registered
Joined
·
2,810 Posts
Discussion Starter #20
My guess for a Honda resistor plug cap would be 5000 ohms. Yours sounds like a non resistor cap. They tend to increase in resistance with age if it is a resistor cap. I had to replace all four on my 72 Honda CB500 because they ranged from 5300 ohms all the way up to around 12,000 ohms which drove that bike's ignition system crazy. Much mo' betta' now.



Rick

Interesting, I've never learned so much about plug caps till this week.. Always good to know.

I got another one off an 86 125.. Probably won't get to mess with it till this weekend.. LONG week at work.. Generator exhaust caught on fire, fire alarm computer crashed, contractor shorted out emergency circuit and tripped switch gear breaker, tablets crashed and can't log work orders. And I still have one more day to go...



Sent from my iPhone using Tapatalk
 
1 - 20 of 29 Posts
Top