why does sparks just disappear?

[Jim mac]

project 185s, dragged it home a few weeks ago, finally installed a cdi, hooked the hacked harness up, hooked the black wire to the coil instead of the green one. bolted on a pull start and it sparks. Seller told me he took the locator pin off the cam for another project. I installed one off a spare cam, stuck a pair of springs on the advance weights and bolted it back together and....now no spark! swapped cdi, swapped coil, coil wire, plug. I guess I did the quick and easy things.
But it never fails to amaze me, a simple job always goes south. I bought a extra pit bike harness, im thinking if the stator checks out, I'm just going to use the entire harness with switch and all. jim

[MrConcdid]

Well, after a few years, men and woman just kinda grow apart, its just the way life is Jim. the sparks go out.

Mrc_builds, I am sorry I just had to.
Check the ohm reading on your coil.

[Jim mac]

hahaha. I think the sparks gone out on my trike hobby right now. instead of making 1 really nice 185s, I ended up with 4 projects and just burnt myself out on them. jim

[patriot1]

Sounds like 80% of the stuff I work on Jim, but every once and a while I hit the preverbal golf shot that keeps me in the game!!

[Jim mac]

swapped out a complete ebay pitbike harness, cdi,switch, coil and wire. got spark but won't start. feels like it's got good compression. next up, check timing, check valves.
jim

[patriot1]

Jim: You're way better than this than I am so build your shed! lol I did a top end on my a SX, took my time, checked and double checked the manual, put everything back together and torqued everything accordingly, installed carb, and all else and ZERO SPARK!

It ran before I tore into it, just had low compression... It ran rode and drove and now-NO SPARK...

And to make matters worse, I pulled the main fuse holder apart trying to check that today.

But good news is coming soon and I'll figure this one out as well!!

[Jim mac]

getting too old for this stuff. went to the basics. my yardbsale compression tester may okay not work. so I get the flywheel to the F position and notice the valves are open. pop the cdi cover off and timing sprocket is lined up but the pulse gen is 180* off. it's got hardware store 10mm bolts on the cam gear. It's 180 out. so it's all lined up but still won't start. Got a nice blue spark. tried starting fluid, new plug, nothing. the pull cord is a bit short. next up, pull the recoil and spin it with my large drill.
Maybe it's just low compression. maybe it's time to pull out another mystery motor. jim

[MrConcdid]

The cam is 180 out, not just the sprocket.
Common mistake, cam lobes should both point down at TDC no load on the valves.
MrC

[Jim mac]

when I first checked it, both valves were open at TDC on the flywheel. now it's on compression at TDC. I think its just low compression. jim

[patriot1]

Jim: Keep us posted on what you figure out. My 200 is the same way except I have compression, fuel and fire but it won't start. Won't even hit with starter fluid. It will push start easily, but can't get it to do anything with the rope.

[MrConcdid]

I tore down a 200e last night, it had 35psi compression. It was the rings, they had collapsed.
mrc_builds

[Jim mac]

I hooked my compressor up to the cylinder, ran it to about 100 psi, held the pull handle so the motor stayed in position. No air out the pipe or carb. felt a little air coming out of the vent. but not very much.
put the flywheel at TDC, O lined with the mark on the housing. pulse gen lines up to the pick up. both valves I feel a little gap between rocker and valve. This thing is starting to make me mad. jim

[Jim mac]

SUCCESSSSSSS!!!!!!.
went out tonight and decided to start at square 1. pulled plug,recoil, valve covers, pulse generator cover and looked at the chain and sprocket.
got it all zeroed out at TDC sprocket exhaust was tight, loosened it by feel, probably too big. but the rotor wouldn't line up to the pick up. Then I got to thinking..guy I got the trike from said he needed the springs for his suspended 185s. I pulled another rotor and eureka! the rotor notch and magnet is in a different position. Swap the correct rotor and it runs!. jim

[patriot1]

lol! The preverbial golf stroke! Good job Jim!

[MrConcdid]

Congrats, never give up. lets see some pictures
#mrc_builds