someone please help

[sirfunkeybut]

ok so, i rechecked the spark and it's all erratic. It will spark as soon as i start to crank and will go up to 7 seconds or so before another spark, sometimes shorter, sometimes longer. i tried checking the pickup with a DVOM and i cant get any reading from it. so would this cause this spark/no start issue?

[DonTZ125]

The crank pickup signal is AC intermittent, and can really only be read with an oscilloscope. Check your pickup wires ; if the pattern is coming in backwards the TCI will get seriously confused.

[sirfunkeybut]

i thought i read on another thread that you use an ohm meter and measure the ohms across the wires and it should read around 120 ohms or so. i did this and get 0 ohms.
i took the spark plug boots off and ohmed them and two read about the same and the other two read nothing compared to the other but were pretty well matched with themselves. i also trimmed them back a little for a better connection and now it just backfires twice as much so i guess its progress?

[sirfunkeybut]

where can i find a new set of boots for the wires?

[DonTZ125]

Sorry - I thought you were talking about measuring the actual signal. Brain cramp, never mind ... Yes, you should measure a resistance of 80-120 ohms @ 20C across the pick-up coil wires; if you are measuring 0 ohms, then there is a short, likely right at the coil where it joins the wires - have a look. If this short is intermittent (but usual), then that would prevent a start while still giving you the occasional spark.

Plug boots can be had at any bike shop; it doesn't have to be a dealership.

[sirfunkeybut]

the coils themselves tested fine, but when i took the boots off and ohmed them and thats whats wrong im hoping. when i called the local dealership they said that theres resisters in the boots that will rattle when bad and 3 out of 4 rattle. They're only 8 a piece so im gonna replace all them. i hope this solves this goose chase of problems

[sirfunkeybut]

so i was checking some wires after reading through another thread that i found and it said that if you test the red/white wire and the white/blue wire on that connects to the TCI to the negative side of the battery it should read infinite ohms. Mine reads ohms so is this telling me the pickup coil is bad? I've checked the connections and found no corrosion as well as pulled the stator cover off and found no contaminants. and if so is this why I'm not getting any spark, or the erratic spark?

also when i checked the ohms of the pickup, it read 160 ohms and slowly but steadily dropped. It says the it should read between 80-120 ohms at about 68* F. its probably 40* F out right now so would this explain why its reading so high?

[DonTZ125]

Not sure which wires you're looking at - are these on the 4-pin (or 8-pin) connector, or on the 6-pin? Which position?


Cold reduces the resistance of copper wiring; you should have a lower reading at 40F vs 68F.

[sirfunkeybut]

its the left plug, using the red/white and black/white

[yamaha_george]

i tried the car and it just backfires out the carbs and the pipe. this is getting to be quite hectic and seeming not to be worth it.

SFB,
Walk away from the problem. You are seeing the wood but no trees. In a frustrated mood you will not accomplish anything (after 50 years + of bikes I can say that ) Frustrating as it may seem leave it walk away rest sleep on it for a week and Start at the beginning again !

when you go back at it be sure
1} battery fully charged

2}Have a photostat copy of the cut down wiring diagram that MAWLER did to trouble shoot just the ignition system (I
would give you a link but am in Hospital on a very slim line to my servers)

3} have a fairly decent digital meter to use

4} a fresh plug set NOT the old ones cleaned ) gapped properly 30 thou if memory serves

5}The old set should be cleaned and dried in the oven

6} plenty of liquid for you NOT beer :-{

My old saying for students "there is no such thing as a stupid question EXCEPT the one you do not ask as the answer will never be given !"

[DonTZ125]

Something is very wrong here - you are correct, the p-u coil wiring is completely discrete and isolated from the rest of the harness. If you have ANY continuity to the battery, at whatever resistance, then you have a fray / short in the wiring.

[sirfunkeybut]

So I replaced the plugs and boots and now have a good consistent spark but still no start. I've tried spraying starter fluid and still no go, I've checked and re-checked the fireing order and still no go. Any other suggestions.

[sirfunkeybut]

the new boots i got when ohm tested read 4.96 measured on the 20k. on the "no spark now what" page it said they should read 9k-11,000. so does this mean that the boots i bought wont work?

[sirfunkeybut]

After going through everything twice(under exaggeration) and still no start I figured I would check the valves. I'm not to familiar with valves, so I'm not sure what I'm doing totally. I took the .004/.008 feeler gauge and tried to put in the intake sides while the lobes were in the right place and all but one valve were to tight. The exhaust side took the feeler gauge that was within the specs and not the next thicker one so I assume they are all good. My question is, what do I need to do to fix the intake valves.

[sirfunkeybut]

anyone? how am i to know what shims to get since i cant measure the clearance?