Dropping 2 cylinders again

[dpep]

Last June I rode from Jax up to the Maine ride on my 850. On that trip I started losing two cylinders after the enginge had been runnining for a time. . At first I could keep them by keeping my rpms high (over 5000), but eventually I couldn't keep 4 cylinders regardless of rpm. I tried various fixes, including swapping out coils, in Luke's garage, but the problem always returned. I decided it had to be my Dyna III igniter even though I only had a little over 10,000 miles on it. I ordered a new one and got it replaced at the Suzuki dealer outside of Laconia. The problem didn't retrun for the rest of my trip and the return to Florida.

Well, now it's back. I took a ride to St Augustine (70 miles round trip) and just a few blocks from my house I again lost two cylinders. They dropped out more suddenly this time. I am having heavy oil consumption and I first suspected fouled plugs. But after I removed and cleaned off the plugs I still only had two cylinders at startup.

I can't believe The Dyna igniter has gone bad after less than 2000 miles. But if I have further eliminated the coils and plugs, where else do I look?

[Anonymous]

I would say

I would guess the coils are bad only if it does it while the bike is hot, if all the time then its time to get the dyna S and get ridd of the box, my xs1100 had a simialir problem I swapped the coils didn't help cause both coils where going bad, butI really think its the box again, electronic stuff I have found either works great and lasts along time or it is short lived, and is very short lived if you have had any voltage spikes, check for loose battery cables and connections that may cause spikes as well as your chargeing system out -put, may be bad rec/reg if excessive, or if you have the third leg of the alt. tied direct and your running with the headlight off, may be over loading the R/R, also look for excessive coil resistance, this may be putting a strain on the box if its alot.

[saaz]

Is it the shared cylinders off a coil?

I had a recent frustrating experience like this. Just in case it may be the problem, mine was the plug caps breaking down when hot. Didn't happen when testing and swapping coils etc. It took out 3 coils before I figured out the problem. The problem was harder to find as once a coil was going it semed like it was the problem consistently.

Good luck.

[redliner1973]

Are the coils stock? Are they the 5 ohm instead of the 3 ohm? Other than that, I wold check the R&R, as posted above, if it is putting out too much voltage, it may be killing the ignitor box. As for the oil consumption, is it all the time, or just in the 2 cylinders that are going out? If not all the time, it may be getting sucked up the rings because there is no igition to keep pressure on the rings.

[Anonymous]

I had the same problem on my 750 Magna. I'd lose two cylinders for no apparent reason at any given time. I replaced the coils (2 on magna) plug wires, plugs. Nothing worked. One of my friends finally told me it was the "pulse generator" 75.00 and an hour of work in my garage had her back on the road with 0 problems. I don't know if our suzis have this electrical part but it's definately something to look into. Good luck, I know it can be veerrryyy frustrating.

[Anonymous]

P.S I forgot to tell you I also went through that cotton pickin' bike with a fine toothed comb checking every possible electrical connection, wire etc etc etc. I replaced the coils twice, thinking I may, just may have gotten another bad one My mechanic told me that in all his years of service, he's only replaced a few coils, mostly in Harleys because the owners leave them switched on :?

[dpep]

Thanks for all the good feedback. I was wrong about my ignition. I do have a Dyna S; I always get my Dynas confused. The coils are Dyna also.

The plug wires or caps may have some role in this. This bike puts out so much electrical noise, it shuts off my CD player above 4500 rpm. On the Maine ride, another rider who had a portable FM radio said he got very bad static anytime he got close to my bike.

The oil consumption is all the time, not just when the cylinders drop. I actually changed coils at Luke's not just swap them. This year I started carrying a spare set of stock electrics--coils, stator & R/R--when I tour. I guess I will have to start carrying an igniter also.

There is nothing more fun to find and fix than an intermittent electrical problem.

[Anonymous]

dyna S

If you have the Dyna S already then the problem is in the connection to the harness from the sensors and power leads on the ign. if you used the connectors in the box remove all and solder the wires these connectors are junk and should never be used,

[KEITH KRAUSE]

Re: dyna S

If you have the Dyna S already then the problem is in the connection to the harness from the sensors and power leads on the ign. if you used the connectors in the box remove all and solder the wires these connectors are junk and should never be used,

The Dyna S only uses one wire (red) to power the modules. If a bad connection is made at the harness, all four cylinders die.
A bad module will kill two cylinders, but I don't think dpep's problem is a bad module.
I would try cleaning or replacing the leads and installing NGK plug caps. A poor connection gets worse as it heats up. If it starts up, I would also check the Reg/Rec for high voltage output. A good carb synch may be needed too.

[Anonymous]

dyna S

Kieth got to disagree The problem that the dealer had with my dyna s and could not fix and sold me the bike cheap, and I figured out, was the main red had a bad connection at the big red wire, it would drop 2 cylinders, some times all of them, this was caused by low voltage, not a total lack of voltage, ( high resistance at the connection) as a side note it only did it once off the choke as the mixture got leaner and the system heated up. and of you read my post you will see that I also mention the pick up connections whitch can cause his problem.

[KEITH KRAUSE]

Ok. Not arguing. There's only 1 new hot wire connected at the harness. If it fails, all 4 cylinders die. If it's a poor connection, all four would be weak. He has 2 good cylinders. I just don't think his problem could be that connection. If he lost a module it would cause his problem.
I still suspect the coil lead/cap connections. The R/R may be putting out too much voltage.

[Anonymous]

coils

When you have weak current the coil with the least amount of internal resistance will be the one that still fires after the one with higher resistance has quit, even new coils will not have the same internal resistance, a used coil will have even more diffence between the two. not argueing just exchangeing ideas and things I have come upon in years. Got to go Iam looking at a couple of bikes on the net that I may add to my collection

[dpep]

I am bringing this old tread back to tell what the problem proved to be. It was due to the mounting of the coils. The Dyna Coil has two holes in the mounting bracket on the back side, one close in to the coil and one further out. The one close to the coil should not be there; it is too close. The picture below shows what I mean.



I had my coils mounted through the front set of holes. You can see they are right next to the terminal coming off the back of the coil. If the mounting bolt wiggles a little it can make contact with the terminal or get close enough for the short to jump the gap once it heats up. Moved the bolts to the outside holes and it ran like a champ. Or at least it did until one of the stator/rr connections burned up and fried my stator. But that is another story.

I mounted the coil this way the last time I swapped them out troubleshooting. I don't know if I was just putting it back the way the mechanic who put in the ignition had them, or if it was all my doing. It was dropping out before I started messing with the coils and before I paid over $200 for a new Dyna Igniter. I didn't take any pictures of it when the problem first started, so I will never know for sure. I kept the "bad" Dyna but I don't know any way of testing it without remounting it to the bike and riding it around a few hours.

If you ever start loosing two cylinders intermittently especially after the engine has heated up, check the mounting and connections on your coil before you do anything else. It could save you a lot of time and $.

[Anonymous]

short

Good find I will remember that cause I have a set of dynas coming next week