86' 250SX electrical shutdown

[twkmaster]

son was running flat out when everything shut off. have qualified cdi unit/coil/voltage regulator. next step i guess is to check pulse generator and alternator. anyone else ever had this happen? if so what did you find?

[TRI-Zbrian]

are you sure its because you lost spark maybe the timing chain snapped on him or something like that

[twkmaster]

it's doubtful since we just rebuilt motor last summer. he said it just shut off and coasted to a stop almost like it had run out of fuel. we checked all the obvious things. it really sounded like an electrical failure to me but i wanted to get other perspectives.

[TRI-Zbrian]

have you taken the spark plug out and laid it against the head and tuned the engine over to see if its got spark? also maybe do a compression test put your finger over the spark plug hole and turn the engine over and see if it still blowes your finger off.

[Bumb]

That has happend to me once. I think it came down to a lose wire.

[twkmaster]

yep, checked compression, (good) but no spark visible from plug. but, we checked my 250es for spark a few times and there wasn't much and it runs like a scalded dog. checked coil and it showed no reading from contact to contact wherreas the coil from my ES read normally. put the supposed bad coil on my ES and it fired right up. mystery to me. :?

[TRI-Zbrian]

hmmm maybe like said before there is a loos wire soem ware also lol try this literaly im not joking this is how i test machines to see if they have a weak spark literaly take the plug out connect it to the plug wire and touch the tip of it with your finger and turn the engine over and see if you get any type of a jolt if you do its got a very weak spark but if you dont then well you arent getting anything out of it.

[twkmaster]

think we did try that and my son got a jolt. but, we've been working on both trikes alternately so it may have been mine. got mine running great now and it is time to work on his SX. supposed to work o n it Sat. so i was hoping to learn somemthing before i pulled the rotor etc. any way to check alternator w/o it running that i don't know about? i work on locomotive alts./gens. but two different animals. guess i could break down and buy a shop manual. :rolleyes:

[jeswinehart]

i e-mailed you a couple of scanned pages,,, good luck !


john