HS40 with lights wont start....

[motomonster212cc]

SooOOOoo... I got a 1970 Rupp Roadster with a HS40 and lighting coil. Replaced carb (Oregon brand), new plug set @ .30, new points (set @ .20) new coil, new condenser. Got spark (shocked me good when pulling and holding spark plug wire end. :laugh, compression seems good at exhaust pipe (hand over end of exhaust), gas is going to carb, timing should be ok (no sheared key at flywheel)

i'm a pretty decent mechanic, work on cars, trucks, boats, heavy equipment, etc.

This HS40's got me baffled. All the lights including the brake light work when I pull the cord fast enough, so I don't think its some kind of grounding issue. even cleaned and replaced the ground plug/bolt on front of the engine.

Anyone here got any other ideas? I'd really like to take this thing for a spin (obviously)

Thanks in advance!

 

[Harleys Papa]

Is the plug getting wet?

 

[markus]

will it at least spit, pop, or sputter?

did you remove the magneto assy when you changed the coil out, if so did it go back into the same exact spot that it was in before. Does it actually have visible fat spark at the plug or did you just see if it would shock you. is there adequate clearance that nothing is touching or very close to the plug wire end/plug- those bikes can have close quarters depending on what plug you use.

Have you tried it with the harness unpluggged from the engine?

 

[motomonster212cc]

Harleys Papa: Not 100% sure if plug is getting wet haven't pulled it to look, the last time I did it was dry, but have since then put a bit of gas down there, reinstalled plug, pull cord... nothing, not even a cough. I try it again now and see if its wet..

markus: I get nothing, not a spit, pop or shutter. I did remove the magneto, I had a brainfart at the time and didn't mark where is was originally, so i put the top and the bottom in the middle when I reassembled. I haven't tried unplugging the harness from the engine, I figured if I did that I wouldn't start. I have unplugged it in the past and plugged it back in to make sure it had a good connection, then pulled, nothing. I'm going outside right now to try it completely unplugged and see what happens....


Should be back in 10 mins MAX.

 

[capguncowboy]

If you removed the magneto/stater from the engine, you need to get it put back exactly how it goes. On these engines, the timing is very specific -- even as little as 1/16" off and it won't start, or will sheer keys and make you angry, like you've never been before!

I put together a tutorial a while back. I'll see if I can dig it up. If you don't have a Tecumseh Dial Indicator, you'll need to remove the head to locate .035 before top-dead-center and set the timing.

Here is the tutorial: http://www.oldminibikes.com/forum/t...tecumseh-engine.html?highlight=setting+timing

I hope that helps

 

[motomonster212cc]

cajuncowboy: Thanks for the link, I'll read that here in a few.

Went and pulled the plug, it was wet. Unplugged the front plug and tried it, still nothing... what I did notice though, the rear taillight comes on regardless where I have the light switch placed (up, middle or down, its on)

 

[motomonster212cc]

tried another plug, just to make sure (even though the one that was in there was brand new), didnt help.

 

[motomonster212cc]

capguncowboy: I read the thread you posted, couldn't find a Tecumseh dial indicator for sale, so I'm going to get a different brand one and see what happens. I did take pictures of the original setup up before I took everything apart. I also, put the magneto/stator back exactly where the bolts/washers left an impression (ring) on the metal from before I took the mag/stator off. I'm still getting a dial indicator just to make sure. I'd prefer not to take the head off, don't want to open another can of worms.....

 

[motomonster212cc]

UPDATE!:hammer: Got it running, and she's running great. Here's where I went wrong.... (almost embarrassing). I sat here for awhile and thought about what I could have possibly done wrong... then it hit me.... I haven't worked on my old VW bus in awhile, and I so I started to think about the points and condenser on it...

I put the damn negative wire AND the positive wire from the coil to the points. DUH!! Unhooked the negative wire, put it where it belongs, on the small bolt that holds the condensor itself in place, replaced the flywheel, cover,etc. and PRESTO, started and ran great on the first pull!

Got to late to take it on a test run, but the lights work and everything,

Thanks to everyone on OldMiniBikes and especially the people that replied to this post, hopefully this will help another person out in the future.

 

[buckeye]

Aww man, sometimes it's the simple things we overlook.
Glad she's running. Got pics?
We love pics. Good ones, bad ones, videos, just good old mini bike pics.
Thanks for the update.

 

[capguncowboy]

Don't feel bad. I sheared about 10 flywheels keys on a Rupp HS40 before I realized I was putting them in backwards :doah:

Glad it's working for you