300/440/550 X-2 starts after I let off the starter??????

[Dragonfly]

I have an 87 X-2 built 2 winters ago running great. this summer it develops a starting problem.

when the batt gets low but still cranking good, i can hold the start button and it wont start untill after I let off it and then it fires up. but only for a couple more starts and then all it will do is crank. as soon as I put the charger on it it'll fire right up.

Now what part of my ignition is getting weak??????

Any ideas????

 

[douglee25]

I have an 87 X-2 built 2 winters ago running great. this summer it develops a starting problem.

when the batt gets low but still cranking good, i can hold the start button and it wont start untill after I let off it and then it fires up. but only for a couple more starts and then all it will do is crank. as soon as I put the charger on it it'll fire right up.

Now what part of my ignition is getting weak??????

Any ideas????

Do you have an MSD ignition? This happens with that type of system when they go south (I believe).

Doug

 

[Mouthfulloflake]

Its not just MSDs that do that.

thats how an electronic ignition works.

when you let off the button, it makes a spark.

thats exactly what happends everytime the flywheel passes the pick up, it signals the ignition to turn off the power to the coil, which makes a spark.

my question is, whats your battery voltage when this happens?

I suspect its more of a low voltage issue than an ignition issue.

I dont know much about 650 ignitions though.

( assuming a x2 is a 650 engine right?)

 

[sflsurfrider]

Its not just MSDs that do that.

thats how an electronic ignition works.

when you let off the button, it makes a spark.

thats exactly what happends everytime the flywheel passes the pick up, it signals the ignition to turn off the power to the coil, which makes a spark.

my question is, whats your battery voltage when this happens?

I suspect its more of a low voltage issue than an ignition issue.

I dont know much about 650 ignitions though.

( assuming a x2 is a 650 engine right?)

????????????????

 

[Dragonfly]

Its not just MSDs that do that.

thats how an electronic ignition works.

when you let off the button, it makes a spark.

thats exactly what happends everytime the flywheel passes the pick up, it signals the ignition to turn off the power to the coil, which makes a spark.

my question is, whats your battery voltage when this happens?

I suspect its more of a low voltage issue than an ignition issue.

I dont know much about 650 ignitions though.

( assuming a x2 is a 650 engine right?)

87 650 X-2 stock ignition with aluminum charging flywheel


batt voltage is good!

 

[extreemthrottle]

my old 650sx used to do that. i never really narrowed it down to one thing though. i went through all the electrical conections and checked and cleaned them all or replaced them. also added dielectric grease to them never had that problem again. might want to check your grounds too.. good luck

 

[Mouthfulloflake]

????????????????

to clarify.

an elec ignition, puts a voltage to the small side of the coil, when that voltage is removed, the large side of the coil sparks the plug.

right?

so when you are trying to start, the small side gets 12 volts, when you let off, its removed.

that basically points to an intermittant pickup or trigger coil I would think.

for some reason it isnt giving the coil the ON and OFF it needs to fire the plugs multiple times, its only modulating the coil when you let off the starter button.

clear as mud now right?

 

[douglee25]

to clarify.

an elec ignition, puts a voltage to the small side of the coil, when that voltage is removed, the large side of the coil sparks the plug.

right?

so when you are trying to start, the small side gets 12 volts, when you let off, its removed.

that basically points to an intermittant pickup or trigger coil I would think.

for some reason it isnt giving the coil the ON and OFF it needs to fire the plugs multiple times, its only modulating the coil when you let off the starter button.

clear as mud now right?

True, but isn't that the job of the CDI to do the on/off to fire the plugs? The CDI basically replaces a points setup to turn on/off the 12 volts. No?

Doug

 

[Mouthfulloflake]

no, actually the pickup/trigger replaces the points making and breaking the primary circuit. ( wlthough, it does this thru the CDI, so you are right, but one wont work without the other)

thats why though, if the CDI or trigger is BAD, it will spark when you let off the starter button.

there is something very strange when that happens and keeps running, almost as if for some reason the cdi is only energized when the starter switch is NOT depressed.

possibly a wiring issue there.

 

[zunman]

Hey I was talking to you on the pwctoday forum about the same issue, I found out that I had a bad CDI!!!! Mine is MSD though.

 

[Dragonfly]

thanks! I got my book out sat but it rained all day here, so I didn't get a chance to take my meter to it.

mines a stock 87 ignition!