Topic: Looking for troubleshooting Help on my 76 750F

[smee]

Alright. Sorry for the radio silence. It's been too hot here to work on anything and it's finally starting to cool down.

I put in new plugs, new carb clamps, put it 87 octane and it ran great for a day. The next day it's back to the same 'ol crap. I'm at a total loss here!

Today's symptoms: I had a hard time starting it up. It starts, but dies immediately, with or without choke on. It's worse with choke on. Holding onto the throttle it's obvious it's not running on all 4 cylinders. Pipes 1 and 4 are hot, 2 and 3 not so much. Took it around the block. It struggled. Plugs seem ok, except 2 and 3 are a little wet.

I left it on it's side stand overnight with petcock off.

(Looking back at my previous posts maybe I'm actually making progress considering how the plugs l look... )

Few things I've noticed:

Not sure the order of your newest spark plug photos, but your timing is off on at least 2 of the cylinders. Recommend to re-check cylinders 1/4 and 2/3 and adjust.

One of your older photos of the intake boot had fuel on it. Any leaking from your carb bowls? Float heights set correctly? Recommend to re-check and raise them if necessary to lean it out a bit.

[Don R]

 A pretty blue spark is a good one, a tiny yellow spark is not as good. 

[tofan]

Wanted to share an update. I think it's finally behaving really well! I've ridden it for a few days now and no issues. The last thing I did was replace the plugs on 2 and 3, fine-tuned the timing on 1 and 4 and found that timing on 2-3 was slightly off. I actually didn't know the Dyna S had adjustment for cylinders 2 and 3.

Thanks for everyone's assistance on this. I couldn't have done this by myself.