Engine Problems (Not running on all cylinders???)

[txironhead]

Is it possible that your regulator's gone out and is frying your electronics? Is the hot wire to the Dyna fused? I'd contact Dyna and see what they suggest, possibly when they take yours apart they can tell you what happened to it.

 

[Mgriz]

Alright, so after an embarrassingly long time of the bike sitting in my garage collecting dust. I decided to make an effort to get it back on the road.

I bit the bullet, replaced the rectifier and regulator with a new single R/R piece and purchased another Dyna S. I went though what was left of the electrical system and got rid of a mess of nasty wiring the bike had from its previous owners and cleaned the carbs again. I got out my trusty multimeter and checked the ignition system thoroughly. Everything is within spec and timing is right on so I was feeling pretty confident.

Didn't work out so well. It sounds worse than it did before and that's because its still running on 2 cylinders. Except now its only firing on 1 and 2! I guess I'll check the compression in 3 and 4 tomorrow, not sure what else could be going on. All spark plugs are relatively new, new wires, new coils, new carb boots, etc. Any ideas?

 

[49er]

Alright, so after an embarrassingly long time of the bike sitting in my garage collecting dust. I decided to make an effort to get it back on the road.

I bit the bullet, replaced the rectifier and regulator with a new single R/R piece and purchased another Dyna S. I went though what was left of the electrical system and got rid of a mess of nasty wiring the bike had from its previous owners and cleaned the carbs again. I got out my trusty multimeter and checked the ignition system thoroughly. Everything is within spec and timing is right on so I was feeling pretty confident.

Didn't work out so well. It sounds worse than it did before and that's because its still running on 2 cylinders. Except now its only firing on 1 and 2! I guess I'll check the compression in 3 and 4 tomorrow, not sure what else could be going on. All spark plugs are relatively new, new wires, new coils, new carb boots, etc. Any ideas?

You say that you have now checked out the ignition system thoroughly and yet it is still not running on 2 cylinders. Worse still the problem has moved from a likely coil problem on 1&4, to cylinders 3&4 not firing. Both 3 and 4 are fired on different coils, which means you either have a crook set of leads to those plugs, or your carbs are the problem. How have you established that 3&4 are not running? Is there no spark, or are the pipes just cold? If It's cold pipes, you are likely to have plugged passages in the pilot circuits on those carbs. If you don't have spark, cut back the lead at the caps and reconnect them and try again. Also re-check all the connections at the coils.

Were you working from the correct wiring diagram for your model when replacing the old harness wiring?

 

[Mgriz]

Thanks for the help... I finally got it running and on all cylinders at that!

Yes, the 3+4 pipes were stone cold... I checked spark and had a nice strong spark for each plug on their respective cables, compression was within spec... so I pulled the carbs.

Sure enough the bowls for 3+4 were bone dry, I had assumed since the plugs were wet and smelled like fuel, the cylinders were getting fuel. Guess they started out that way. Anyhow, there was some green goo under both float needle valves. Cleaned them up and threw the carbs back on the bike and it fired right up. Looks like the electrical work payed off.

Thanks again!

 

[49er]

Thanks for the help... I finally got it running and on all cylinders at that!

Yes, the 3+4 pipes were stone cold... I checked spark and had a nice strong spark for each plug on their respective cables, compression was within spec... so I pulled the carbs.

Sure enough the bowls for 3+4 were bone dry, I had assumed since the plugs were wet and smelled like fuel, the cylinders were getting fuel. Guess they started out that way. Anyhow, there was some green goo under both float needle valves. Cleaned them up and threw the carbs back on the bike and it fired right up. Looks like the electrical work payed off.

Thanks again!

Good to hear it's running right again. There's no short cuts to cleaning carbs.