No combustion on 3 & 4

[mindtrip]

I figured i would move this thread into here, since now i have ignition and electrical is working fine.

Check the previous thread here: http://www.thegsresources.com/_forum...d.php?t=180175

I have no combustion in cyl 3 and 4. Oh yes, I have a nice blue spark coming from 3 & 4. The engine runs and idles on 2 cyls and revs to 5k. Ive dipped the carbs and synced them as well. New o-rings etc.

any advice would be great

-Andy

[BassCliff]

Hi,

Did you check to make sure the new float bowl gaskets matched the old ones exactly?









And there are other obvious questions like; Are you sure the carbs are clean? Many here have had to clean them two or three times to be thorough. Are the float heights set properly? Is there fuel in the float bowls? Etc.

Keep us informed.


Thank you for your indulgence,

BassCliff

[Gonzo]

Check the plugs to see if they are wet with fuel. If not, I would check your bowls to see if they are full. If they're empty and after being primed fuel still doesn't get through, I would assume there is a blockage somewhere (despite the fresh cleaning). I'm sure there's other possibilities, but that's what comes to my mind right now.

[tom203]

Make sure plug wires 3 and 4 haven't been interchanged- remember plug 4 connects to left coil with plug 1.

[mindtrip]

Alright guys. checked the float bowl gaskets and they are all punched with that hole. Second, i put everything back together and tightened everything up and fired her up and wouldnt you know it, cyl 3 and 4 are firing. I revved her up and she gets all the way to 8 or 9k. but im still having a surging issue. It seems like the bike will rev high and then drop back down to 3 to 5k and surge. Sounds like the cyls are firing sometime and then not firing at all.

my plug wires are connected like this.
firing order 1-2-4-3 coil one has plug 1 and 4 and coil 2 has 2 and 3

[Gonzo]

How's your timing look?

[mindtrip]

Not sure how to go about checking that. I do have a timing light accessible. Seems to be getting some black smoke out of the tailpipes. Ill make a video of what its doing in a second.

[mindtrip]