Test Drive after Rebuild / Question...

[Bookm]

Here's a couple resto pics and video of first test. As you will see, the 440-Rotax was idling quite nicely at first. But soon I lost spark to the left cylinder at low R.P.M.'s. The spark returns when I rev it out, but it's impossible to drive like this.

I tried swapping plugs and the coil with another = didn't help. I'm pretty weak when it comes to engine electronics. Hopefully someone will recognize my symptoms and offer some suggestions.

Also, the belt was WAY stretched and worn. I have a nice new tight one on now and look forward to testing again at lower R.P.M.'s.

[LarryW]

Nice job on the resto. Looks great.

For your spark problem its sounds like the charging coil under the flywheel that puts juice to the ignition coil. My 340 rupp has a charging coil for each ignition coil. One side went dead like your saying. I swapped the coils left and right and the same cylinder still wasnt working. So I then rewired them so the charging coils are swapped with the ignition coils and then the other side when dead. Thats how I narrowed it down for me. I am assuming yours may be similar? Good luck
Larry

[Bookm]

Ah yes... the highs and lows of vintage hobbies. Removing a big engine through that little Argo hole is not fun. If only I didn't have bones in my arms it would be waaay easier! But now it's out and I now realize there is ONE tool I don't own... a three-way puller (to remove flywheel). I'll go get one after a much needed break from scraping my knuckles and cursing up the neighborhood, LOL

Something to note in pics... 60's fibreglass floor pans and hood scoop (turned backwards for that cowl induction look

[Bookm]

I would imagine both internal coils should look the same. It' looks like one has been replaced. I'll replace the other one. I have a spare motor to pull parts from.

[Mike]

That has to feel good getting to drive it some although I'm not so sure that your dog was thrilled about it

[LarryW]

You have a coil for the lights/charging and another for ignition coil. Its been a while but I believe my ignition coils where stacked on top of each other and I had 3 total under the flywheel. Hard to tell on yours but looks like you only have 2 coils total. You may have a point/condenser problem if you only have one coil running the ign. coils.

EDIT: The list below shows yours is the same way as my rupp with 3 coils.

[Bookm]

Thanks for the followups. I'm slowly starting to comprehend how this stuff works. I ran out of weekend (and enthusiasm) but will take a closer look tomorrow (will chase the wiring)

Found this diagram but I down have the part number reference sheet.

[Bookm]

Problem solved. Point gap was under spec and one set of points corroded. A little polishing with emery cloth and both plugs spark a glorious bright blue once again

[LarryW]

Thats great to hear.

[ArgoGirb67]

good deal problem solved.the parts argo i bought has same air filter setup(440 kohler).you may want to relocate muffller back to outside of body(should be metal box where you have the tin plate,muffler under it)to keep temps down under hood.oh your hood is backwards.last pic is of my 4 stroke,the others are the 2 stroke,first shows air filter and duct for engine cooling.2nd shows hood and you can see the "mufflerbox" i was talking about,muffler sits above front tire,HTH