Pamco Electronic ignition vs. high output?

So that kills them? How long can you leave the key on before something goes wrong?
 
Travis,

About 5 minutes. Points have the same issue, of course. The factory TCI and some other aftermarket systems have a built in time out if the engine is not running.
 
I have an 81 650xs with an 83 motor im thinking i need to replace my coil as well. I was looking on mikes and there are so many to choose from and none of them seem to have the wiring harness will I have to splice them in? And on any of these upgrades will the bike have to be rejetted and how do I find out wich jet kit to buy?
 
This coil no re-jetting required. Jetting changes are for a change in free flowing intake and exhaust.

High Output Replacement Ignition Coil
High Output Replacement Ignition Coil - for 80-84 XS650's with Factory TCi
ignition (dual lead - 1 used per bike ). Used on 80-84 models Only, and is Not
for contact point systems. Mounts to stock brackets. Plug Wires not included.
Not for use with Boyer Ignitions. Mount this coil to stock bracket on opposite
side and with high tension plug wires facing to front of bike ( Red/White wire
from stock harness goes to + terminal on coil).

WARNING!!! Do not operate or apply power to the ignition system with one
or both spark plugs disconnected. Operating or applying power to the coil or
ignition system with one or both spark plugs disconnected will cause IMMEDIATE
FAILURE to the coil. Ignition coils are NOT WARRANTIED for this reason. Part #17-6803$37.50 USD Ea
 
i was looking at this one and will order it i am going to make sure that my coil is the problem im having first. the bike was popcorning but i found out that the exhaust was not properly mounted into the engine. it looks like they wanted to replace the doughnuts but instead just put another set on top of them. then also they put k&n air filters on the bike and i dont know if they re-jetted after that. i wanna get the bike running then go from there. thank you for your help!!!!
 
javafinger,

You will need the complete advance setup, but MikesXS has several kits that include all the parts you need.
 
I have an 81 650xs with an 83 motor im thinking i need to replace my coil as well. I was looking on mikes and there are so many to choose from and none of them seem to have the wiring harness will I have to splice them in? And on any of these upgrades will the bike have to be rejetted and how do I find out wich jet kit to buy?

With the "Ultimate" 17-6903 coil I do recommend that you increase the main jet size for BS34's in the later models because the mixture is more completely burned due to the hotter spark so the result is similar to running a slightly lean mixture. I suggest that you go up one main jet size to 135 from the stock 132.5 .You will still get better gas mileage with the larger mains due to the more efficient burning of the mixture.

Here is a chart of some tests that I ran with my stock '81/H:

iridium.jpg


The higher voltage from the 17-6903 "Ultimate" coil allows you to open up the plug gap to as much as .040 to increase the exposure of the mixture to the spark and produce a larger kernel of flame that goes on to ignite the rest of the mixture. The larger kernel of flame is also increased in size by the longer spark duration and higher current flow in the spark that produces a hotter spark.

This recommendation to increase the mains to 135 for the BS34's is also suggested by others to overcome the very lean mixture of the stock BS34's.

www.mikesxs.com has the 135 jets available for $6.50 a pair, Part #48-0119.
 
i have just purchased the pamco kit to convert my tci... after reading a little i got the impression that perhaps the iridium plugs i'm running will not be ok with the kit that i purhcased... the regular kit, not ultimate high output... am i ok?

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dillrepair,

The coil in the kit you got produces about the same voltage as the stock TCI coil, so you will see the same performance you currently have with your TCI and the Iridiums.
 
so i should have just gotten the the higher output coil kit... silly... i'm already at 145 main and whatever the bigger pilot jet was with the heiden kit... open exhaust and pods... should i go up if i get the bigger coil? i have some 147.5's sitting here along with the bigger needle jets
keeping up with all this reading is a PITA... but thanks for all your advice guys

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dillrepair,

Generally speaking, you should go up on the mains when you install the 17-6903 "Ultimate" coil with otherwise stock BS34's (see chart above). Once you step out of a stock situation, then each case is different. If you go for the 17-6903 "Ultimate" coil, then just keep keep track of your plug condition. I would suggest that you use Autolite #63's until you get it dialed in because of the high cost of the Iridiums.
 
I have an 81 xs650 special with a crapped out charging system and TCI ignition...otherwise in great condition...feel lucky to have it. I've fixed the busted kicksarter, added a Heiden oil cooler/filter kit, replaced the sump filter, I've got a bright halogen headlgit to install once the charging sys is upgraded, Ive got an xs750 tank to rehab and install, an old seeat to cut down and reupholster, clubamn bars, and I'm working my way thru all the routine maintainance schedule so I can get to know it piece by piece, got new battery from MikesXS, I've got a Clymer manual, I get the importance of reading everything, making notes then writing out the steps required, marking parts as I take them off, taking digital fotos of dissasembly process that I've not done before, and paying close attention to advice from people a lot more experienced than me. I'm a beginner wanting to get better at living with this great old motorcycle.

I have read a bunch of websites regarding switching to PMA (Hughes Handbuilt) and PAMCO ignition swaps. I'm a total novice on electronics so I get a little lost reading the exchanges of info between guys way ahead of me in electronics savvy. However I do I get why these are real good moves to make and get that I need to do these projects in a careful way, and since I am just moving into this new world of hands on motorcycle work......I sure don't expect to be hand fed and I probably missed some of the the details but.... I have some questions I'd like some advice for:

[1] Is it advisable to do the PAMCO ignition swap BEFORE doing the PMA(Hughes Handbuilt kit just arrived)? If so why?..electronics is unfamiliar area so I'm eager to learn whatever I can. If not, I'd like to get started with the PMA kit sitting on my work bench.

[2] Which of the various PAMCO ignition kits from Mikes would be best for my bike? I do not expect to build a high performance engine..just going for max reliability.

[3] What are the big ignorant errors a novice like me should be aware of in doing these swaps?

[4] I have read the correct order of the projects I have in mind should be [a]do the ignition, then do the PMA, then [c]timing chain, [d] then valves. Is that correct?..again I'd like know the why of this sequencing so I get ahead a little on understanding this wonderful old machine.

[5] Are there training videos that cover the PMA swap? PAMCO ignition swap?

Thanks for any advice,
Charlie
 
larks...,

1. Do the PAMCO first, even if you have the PMA parts in hand. This will allow you to get the engine running, set the timing etc. before you install the PMA as you have to have a running engine to test the PMA. You can also check your timing marks that you put on the PMA compared to the timing that you pre set with the PAMCO. I also recommend that you actually run the engine with the PAMCO powered by a separate battery sitting on the floor as you test the PMA to be sure that the PMA is not producing a harmful high voltage, which could damage the PAMCO.

2. The Part #14-0902 kit has all of the advance parts that you need to convert your '80 Special to mechanical advance. The 17-6822 coil that comes with this kit is a very good, everyday rider coil that will give you about the same performance as your stock TCI coil.
If you do want to go with the "Ultimate" 17-6903 performance coil and kit, then here is a chart that shows the improvement in Gas Mileage with that combination. Generally, gas mileage improvement is a result of the engine running more efficiently. A more efficient engine also produces more power, starts faster, idles smoother etc.

iridium.jpg


These road tests were done on my '81 Special, which is identical to your '80 Special. Note the increase in the main jet size, which is highly recommended.

3.
a. Pull the stock rotor off with the timing mark aligned to the idle mark to make it easier to mark your PMA rotor.

b. Double check your wiring before running the engine with the PMA.
c. Wear safety glasses when you first start up the engine with the PMA as a unexpected high voltage can boil the battery or cause the capacitor to explode.
d. Do not leave the ignition on while you are fiddling with the engine not running.
e. Do not disconnect a plug wire when running the engine. Although the 17-6903 and 17-6822 coils are not as susceptible to self destruction with one wire off, it's just good practice.
f. Put a large fan in front of the engine while running the engine.
g. Charge your battery up overnight before starting this project.. Can't go very far with a dead battery.

4. Do the timing chain and valves first because their condition will affect the timing of the PAMCO.
 
Hi Pete,

I have a couple more questions related to running a Pamco on a 1981 that I am converting from TCI to your system.

1.MikesXS sells needle bearings that are upgrades for the brass bushings, however, your kits come with brass bushings not the needle bearings. Can I use the needle bearings instead of the brass bushings?

I just thought that since I needed to install the whole advance mechanism, I might as well upgrade it.

2. I am going to use the ultimate coil, and I see you recommend increasing the main jets in stock carbs. I run VM34 round slides from MMM/650Central. Do you have any size recommendations for these carbs?

Thanks!

Jon
 
Chi2,

1. I do not recommend using the needle bearings in place of the brass. Unless you have the tool to press the bushings in then there is a chance that they will not be perfectly straight and that results in a binding advance rod. That's why I recommend using only 3 of the brass bushings to reduce the possibility of binding. I also suggest that you read the specific installation instructions on my web site www.yamahaxs650.com for the advance parts. There are a few more tips there to prevent binding.

Here is a video of how your advance weights should "snap" back when properly installed.



2. I do not have a reccomendation for that carb. However, I believe that this link will provide the answer:

VM34-36 Carb Guide
 
The problem with the Iridiums is that they only really work on one of the cylinders because the dual output coil produces a positive voltage on one of the wires and a negative on the other. The Iridiums are only beneficial on the negative wire.

I also found that the Iridiums work best when hot, resulting in poor starting with a dead cold engine.

Hey pete, that's interesting, but I have no idea what you mean by "really only work" - what is the advantage of the iridium that one side will miss out on?

Thanks!
 
Hey pete, that's interesting, but I have no idea what you mean by "really only work" - what is the advantage of the iridium that one side will miss out on?

Thanks!

Iridium spark plugs have a precious metal tip that can get much hotter before it melts. Heat encourages the electrons to literally jump off the tip and go towards the ground electrode. If you are old enough to remember tubes in your TV set, you will recall that they had a hot cathode that emitted electrons towards the positively charged plate, and that's the problem with a dual output coil. Only the negative wire actually has any electrons to emit from the hot tip. The electrons are negative and they are attracted to a positive voltage. So, the plug with the positive wire does not have any electrons to take advantage of that hot precious metal tip.

Also, because the electrons flow from the hot tip to the cold ground electrode, the negative wire plug is more efficient, like, 40% more efficient and that is the main reason that modern wasted spark systems have a "high performance" coil in the first place. To overcome the positive wire deficiency.

Knowing this, if you could determine which wire is the negative wire, you just install an Iridium plug on that wire and install an ordinary plug on the positive wire, thus saving the cost of one Iridium plug.

Ford motor recognizes this anomaly and they supply two kinds of plugs in their cars that have a wasted spark system. One of the plugs has the precious metal on the tip for the negative wire, and the other plug has the precious metal on the ground electrode, although the negative wire plug is still mote efficient because the tip gets hotter than the ground electrode.

You can also buy double platinum plugs that have the precious metal on both the tip and the ground electrode.

One of the ironies here is that the Iridium plugs work better on a stock points system because both coils produce a negative voltage, although the benefit is questionable because the stock points coils produce such a weak voltage that there is not enough current flow (available electrons) to make a difference.

Now, on the 277 RePhase PAMCO setup there are two coils and they are both negative, so Iridiums on a 277 is the way to go. Perhaps another reason to do the conversion!

I had though about making a dual sensor PAMCO for the standard 360 engine if there was enough interest and understanding of the potential benefit.

Of course, the other argument is that high performance coils, like the 17-6903 "Ultimate" coil produce more than enough voltage and current flow that it doesn't matter about the plug wire polarity, and that's the argument that I believe in.

I find spark plugs fascinating. There are people who get a Masters or Doctorate degree to study and improve spark plugs. Same with golf balls and baseball bats.
 
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Thanks for the verbose explanation, thats very cool stuff. With the unequal efficiencies due to polarity, would it be unreasonable to posit that using iridium plugs could be a bad thing, because they favor the negative plug, thus creating an even greater disparity between the efficiencies of the two plugs? It seems like you'd want both plugs to operate at equal efficiency, especially for ease of tuning.

Thanks!
Adam
 
Thanks for the verbose explanation, thats very cool stuff. With the unequal efficiencies due to polarity, would it be unreasonable to posit that using iridium plugs could be a bad thing, because they favor the negative plug, thus creating an even greater disparity between the efficiencies of the two plugs? It seems like you'd want both plugs to operate at equal efficiency, especially for ease of tuning.

Thanks!
Adam

I'm still curious about this!
 
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