Dyna Coil?

[New2Me]

Hello everyone,

I just bought a 1980 XS1100G a couple weeks ago and stumbled across this site when looking for information. This is my first bike and I am pretty excited about it. (like most new things) Anyways I decided the brakes need to be rebuilt and its not a bad idea to update the spark so the pile of parts is growing every day the mail lady stops by. I impulsed when reading posts about coils and bought the Dyna DC2-1 (Red) but then read a post that im not goin to get full voltage so now I think I want the (green) 3 ohm. Can someone verify if that part number is DC1-1?

Like most bikes it seems my carbs need attention and Im a bit intimidated by 4 of them. As a kid 1 carb was enough for me. Heck if the bike could be easily retro fit with 2 carbs id jump on that! The person I bought the bike off of pulled the air box and installed pods and a 4 into 2 exhaust. They replaced the main jet with 130 (or something close).

If anyones feeling generous today this are the "problems" I want to solve.

1. Coils number and wires (8.8mm stranded?)
2. What jets are others using with the same set-up
3. After cruising a for a while and I hammer down I tend to miss 2nd and recently 5th. Does anyone else have this problem?

[CatatonicBug]

Welcome to the world of XSives! If you haven't yet, make sure you take an MSF rider course.

I have the dyna coils on mine, but they're yellow. I have no idea what the part number is though...

These bikes are known for an issue with 2nd gear. The symptoms usually start with jumping out of gear when you hit the gas hard. There is a tech tip (top of the screen, under XS11 Info) that walks you through what is referred to as the "Dremel Fix". It can happen on any gear, but most commonly on 2nd for the XS's and 1st on the XJ's. Yours may be having the problem in both 2nd AND 5th.

[TopCatGr58]

Hey there,

Well, I just reviewed the Dyna Coil Upgrade Tip that Gary posted back in 2003 in the tech tips, Repairs, Electrical section. The DC2-1 coils he used he says he was told by Dyna that they were rated for 6 volt systems?? They are the lower 1.5 ohms coils that would work with the 78-80 series ignitions with ballast resistors. The BR drops the voltage to the coils to about 9 volts, but that's still 3 volts MORE than what these coils were supposed to be run at?

I just downloaded the 2011 Dynatek catalog, and they still list the coil as a 1.5 ohm design, but they don't specify the voltage...on ANY of them?? I'll be dropping them an email requesting clarification of their voltage requirements, or ranges for these two types of coils we are interested in.

The DC1-1 coils are the 3.0 ohm style, and they can be used in the older Pre-81 systems, just need to bypass the BR and it's resistor so that the coils see the full 12 volts at all times.

Pssst, Bug....I think your YELLOW coils are ACCEL ! Dyna uses black/red / green/ blue, but not yellow.

And yes, stranded solid core style wires are what are used, either 7mm or 8.8.

The carbs are little more tricky, because you "might" have a set of the early 80 bastard carbs where it has the TUNNEL between the pilot and main jet towers, where the Pilot gets it supply via the Main jet and the tunnel, and the pilot tower needs to be capped, and therefore the jet size would be close to the 78-79 series carbs that use the 137.5 stock jet.

If they don't have the tunnel, then they get their fuel supply separately directly from the bowl, and the Mains are reduced to 110 stock size. So..your 130 mains could be too lean or too rich depending on the design of the carb bodies! More info from you about their design..tunnel or not, and pilot jet towers capped or not would be needed before suggestions in jetting can be provided...but there's a jetting guide in the MISC forum that you can review and compare your setup with.

2nd gear slipping is common with these bikes, but not 5th? Are you saying that it jumps out of gear when you WOT in 5th, or does the engine rpms rise but the bike doesn't feel any faster and the speedo doesn't show any increase in speed in 5th?? You could have both conditions, the skipping 2nd gear, and a SLIPPING clutch that could manifest its symptoms in the higher gears under strong throttle load.

Or, what do you mean Hammer down..as in shifting the gears? Yes, it's easy to MISS SHIFT thru 1-2 as well as 4-5 and hit neutral as well the false neutral, so more deliberate shifting techniques are required to ensure full shift stroke and proper gear engagement.

T.C.

[crazy steve]

I'll confirm also that the DC1-1 coils are the ones you want... green.

[CatatonicBug]

Oops! You're right... Accell coils on mine. Brain fart. Sorry. However, I DID have the gear slippage in 5th gear myself. Started in 3rd gear, then went to 2nd, then 5th. Definitely less common in 5th gear though. I have hit the "false neutral" in there too. Strange feeling when you're expecting thrust and only get VROOM!!

[lakecountrydave]

Congratulations on the new bike! This link should help with jetting:

http://www.xs11.com/forum/showthread.php?t=382

[Pat Kelly]

[QUOTE=TopCatGr58;330547]Hey there,

Well, I just reviewed the Dyna Coil Upgrade Tip that Gary posted back in 2003 in the tech tips, Repairs, Electrical section. The DC2-1 coils he used he says he was told by Dyna that they were rated for 6 volt systems?? They are the lower 1.5 ohms coils that would work with the 78-80 series ignitions with ballast resistors. The BR drops the voltage to the coils to about 9 volts, but that's still 3 volts MORE than what these coils were supposed to be run at?


That was my Dyna coil project that Gary posted for me. Dyna told me the 6v coils would work as 12v too. They've vbeen on my bike since 2003 (been that long?). They work great. I kept the ballast resistor too. No problems at all.

[cywelchjr]

Makes sense that the 6v coils would work, since 1.5 ohm with a 1.5 ohm ballast would drop about 1/2 the voltage across the resistor, although in reality what with AC (ok, pulsed DC) impedance added into the picture it raises the actual effective resistance a bit which is why you appear to see 9v across the coil (but your not really seeing that, a DC meter can't really accurately measure pulsed DC like what your seeing there, you would need to use and oscilliscope to really see what they are, and they are probably actually closer to 1/2 across each (try measuring across the ballast resistor sometime). That said, why keep the ballast resistor when you can remove that possible point of failure? I'd say that's what the stock coils really are, is 6v coils, the ballast resistor just drops it down enough to keep them from burning out or drawing too much and burning out the output transistors on the TCI.

[James England]

Yes, the green Dyna 3 ohm coils are DC1. I have them on my bike. You're better off getting rid of the ballast resistor and running the 3 ohm coils, IMO. It's one less thing to go wrong and a failed ballast resistor can, from what I've read here on the forum, stop the bike from running.

My green Dynas have been on for several months now and made an immediate difference to starting and running. They look like a solid piece of kit and mount easily onto the bike, using the original mounting holes (you'd need 4 small L-shaped brackets though).

[New2Me]

Thanks for the quick responses! And yes I did take that MSF class last month. It was a law set by the women if I wanted a bike. Good experience though and will eventually take the "Master" class where you bring your own bike.

As bad as it sounds I'm glad to see other's have the same problems with the trans. The day after I bought it I registered it and went crusin with my brother. But when I got back to town I pulled away from a stop light, shifted to second, hit the gas and looked like a chump that just missed a gear. So I kicked the shifter up and lightly accelerated with no problems. Then the other day I took the bike to the bank and decided to take the long way home. I left a stop sign with moderate throttle and when I got to third it was like I went to neutral and I could feel the gear in the shifter pedal. So I slowed down a bit down shifted and went back threw the gears nicely with no problems.

I'll have to check the original jets that the previous owner gave me and look for a serial number on the carbs to find out what im working with. Start up seems to be my problem but once she's ran for a bit she's good. Even with the choke full on I have to give it part throttle and sometimes nurse it to stay running. This is also the only time I notice a "miss" on cylinder 1 or 2. If I try to drive it with out letting it run for at least a few min. it will burp in the same carb. (I think #2)

[crazy steve]

...But when I got back to town I pulled away from a stop light, shifted to second, hit the gas and looked like a chump that just missed a gear. So I kicked the shifter up and lightly accelerated with no problems. Then the other day I took the bike to the bank and decided to take the long way home. I left a stop sign with moderate throttle and when I got to third it was like I went to neutral and I could feel the gear in the shifter pedal. So I slowed down a bit down shifted and went back threw the gears nicely with no problems...

These bikes really need a firm, deliberate technique when shifting or you'll find that false neutral often. It's been said before, they shift like a tractor. I bought one of mine new, and it did the same thing right from the start until I learned to firmly and fully stroke the shift lever on every shift. If you have the dreaded 'tranny troubles', they'll go into gear, then pop out if you apply throttle; how much (or little) throttle you apply will usually indicate how bad the gears are. Finding a false neutral is shifting method more often than not.

Failure to correct how you shift can turn into the 'troubles' if it's done enough...

[New2Me]

How many of you have done the "dremel fix"? It seems like something you would need to do semi-often since the metal will continue to mushroom and round off. Which in turn is going to cause play in the trans and cause faster wear. Can these parts be bought anymore if it does get to that extreme? (Sorry for the ramble) I'm just curious to see what I've got myself into.


Looking at the Jet Guide I see you go up 1 Jet size for 4:2 exhaust and 2 Jets for 4:1. Does the 4:1 really flow better?

[jetmechmarty]

It's my understanding that these bikes would never have 2nd gear issues if proper shifting technique is used. As Steve pointed out, shifting must be very deliberate. Mine lost 2nd gear as well, and I'm sure I contributed with poor shifting technique.

I replaced the gears in mine with new and performed the "washer move". It works great now, but if I'm not careful I can find neutral between 2nd and 3rd as well as 4th and 5th.

My contrast, I have a XS650 of the same vintage and it shifts with a light click. It's totally different.

My SG has stock jetting and 4 into one exhaust. Last I checked, it was fine.

Marty (in Seattle)

[TopCatGr58]

Hey Pat,

Thanks for that info regarding the tech tip, and your followup report that they are still working well. I wrote to Dynatek, and below is the info request as well as their reply regarding both the DC2-1 and the DC1-1 coils!

> Below is the info entered on the Dynatek Tech Contact form submitted:
> Jun 21, 2011
> ------------------------------------------------------------------------
> -----------
> Inquiry type: Dynatek Customer Tech Support Enquiry
> Inquiry from: T. Curtis Gresham topcatgr(at)cox.net
> Regarding: Sport /Import bikes
> On: To Tech Support
> ------------------------------------------------------------------------
> -----------
> Name: T. Curtis Gresham
> Email: topcatgr(at)cox.net
> Comments: Have downloaded the 2011 catalog, but can''t find the Specs
> we''re looking for. I''m the ADMIN for a website whos members have
> Yamaha XS1100 series bikes, 4 cylinders with a pair of dual output
> coils. Several years ago(2003) one of our members was informed by your
> company that the DC2-1 coils which are 1.5 ohms were rated at 6 volts. 3
> year models of our bikes use 1.5 ohm coils with 1.5ohm resistors in line
> to drop the 12 volts to ~9 volts to reduce stress on the OEM coils. The
> later year model of our bike did away with the resistor and used 3.0 ohm
> coils running 12 volts continuously. We are requesting clarification of
> the voltage requirements for the DC2-1 and DC1-1 series coils to ensure
> we are getting the most spark power from them when installed, without
> possibly damaging them by over driving them with too much voltage??
> Sincerely, T. Curtis Gresham www.xs11.com

Their reply:

Dear Mr. Gresham,

Thank you for your interest in Dynatek ignitions. You may use either the
DC2-1, 1.5 ohm coils with the 1.5 ohm ballast resistor or the DC1-1, 3 ohm
coils without the resistor, it really does not matter in this case.
Personally, I would use the DC1-1's and get rid of the additional part. From a
performance aspect there is no real difference. Both coils are fine for a 12
volt application. If we can be of any further assistance, please feel free to
contact us anytime.

Thank you,
Scott Valentine
Customer Service
Dynatek
1-800-928-DYNA (3962)
http://www.dynaonline.com

Regrettably, they still didn't provide any actual Operating VOLTAGE Specs, and the box in the tech tip as well as the box that my DC1-1's came in also did NOT have any voltage specs? I'm not an electrical GURU, so I don't know all of the rules/laws regarding the power and effect that running lower voltages thru the primary windings would do, but I would think that it would generate a weaker field, that would then generate a weaker impulse when it collapses!?

But most likely the DC2-1's are designed as 6 volt as they told Pat/Gary and why they are designed with 1.5 ohms primary resistance. The DC1-1's have the required 3 ohms that the TCI needs to see so that it won't pull too much current thru it and won't burn it up. And removing the B.R. will provide the full 12 volts to the coils which I would believe to provide the strongest possible spark energy that can be created...30K + volts!!!

Now on to the Gears. Marty is a JET MECHANIC, and they can't install "used" or reconditioned parts in their JET ENGINES...they have to use NEW PARTS! MANY of us have done the dremmel fix, and with UNDERCUTTING the gears they PULL together instead of trying to push/slide apart, and the gears are very strong/hard throughout their construction, so grinding down a little to the inner layers does not necessarily expose much softer metal to the stress.

New gears WERE available last year, but Yamaha keeps dropping more parts from their supplies, so not sure how much longer you may be able to acquire them NEW....and they ARE BACK/UNDERCUT in the new design...they learned!

There's an alignment check you can do with the shifter and shift pawl mechanism under the shift cover.... it's in the repair/service manual. Also you can reposition the shifter lever downward a few teeth on the spline to provide a better angle for your foot so you won't have to pull UP/flex your foot so far upwards to get a good firm complete shift motion/throw!

T.C.

[SFerinTEXAS]

feeling frog y . Cart before the horse. Get what you have working before you try to improve whats not running. OE coils are fine if they are working. Fix those carbs then play with upgrades if you want. Never had a reason myself to f(mess)k with the OE coils if they are working.