Tech Info, Etc.

[pegasus54]

After hearing someone discuss high-output ignition coils and finding a set on mikesxs.com, question is: why would a person change from stock coils to the hi-performance set? Question 2: I heard a rumor of a speedometer that would fit my '82 XJ-1100 that goes up to 160. Any comments/info on that? Any help would be appreciated.

[SFerinTEXAS]

I was going to school you on reading the tech tips on the site about that speedo mod. Then found it was not so easy to find here. My Bad. But I did find it. http://www.xs11.com/xs11-info/tech-t...peedo-mod.html

As far as the coil upgrade there is lots of info on the subject and many who have done it and therefor will tell you why you should do it too.Myself I say if your coils are good save your money(or not , don't really care). I am running 2 bikes with stock coils just fine.If you suffer from weak coils that upgrade is the only practical way to put NEW on these bikes.

15 post in 4 years. Some people get that many a day on average. Good for you.

[Pat Kelly]

Everything that is manufactured is a set of compromises. If the 'best' was used then the product would be too expensive.
Also, what is 'best' for one persons' application might not be 'best' for another person.
Higher output coils will have a stronger (longer?) spark and will, in theory, lead to more complete burn of the air/fuel mixture in the cumbustion chamber.
I think the stock coils put out around 25,000 volts. When I (thought I) had a coil problem I went the Dyna coil route (45,000 volts). My seat-o-the pants dyno noticed a difference in power on a stock engine, albiet a small increase.
This increase wasn't needed, but the bike is for enjoyment and I like the feel of a fast bike.
The coil wires being easier to replace seperate of the coil(s0 is an added benefit.

[bikerphil]

Anything for a hotter spark is good, I even run 12V direct from the battery thru a relay to power my 3Ω coils , I get at least an extra volt that way.

[natemoen]

Anything for a hotter spark is good, I even run 12V direct from the battery thru a relay to power my 3Ω coils , I get at least an extra volt that way.

do you have anu details about this anywhere Phil?

[bikerphil]

do you have anu details about this anywhere Phil?

Sure do, .

http://www.xs11.com/forum/showthread...ght=full+power

[SFerinTEXAS]

Anything for a hotter spark is good, I even run 12V direct from the battery thru a relay to power my 3Ω coils , I get at least an extra volt that way.

I say an adequate spark is all that is needed which stock coils in good shape provide. Hotter than that is pointless, sounds good but pointless.

Assuming chacal @ xjbikes.com knows a bit about these things i quote from his coil section.

And a final note: using hi-performance, aftermarket coils (like Dyna or Accel brand) will generally NOT "improve the performance" of your bike in any measurable, meaningful way if your factory coils are performing okay.

http://xjbikes.com/Forums/viewtopic/.../start=15.html

[crazy steve]

I say an adequate spark is all that is needed which stock coils in good shape provide. Hotter than that is pointless, sounds good but pointless....

Well, that's not entirely true... I'll agree that high-output coils rarely deliver any significant power increases that can be quantified on a Dyno with a stock motor, but they do help with starting, can fire worn plugs better, and can help with preventing low-speed fouling. That's why Yamaha went to the trouble of fitting the ballast resistor set-up on the earlier bikes; increasing the voltage into the coils on starting effectively 'makes' them high output during the starting cycle. If you're fitting them for a 'performance' gain on a otherwise stock motor, you're wasting your money.

But if you're messing with things, like running a more agressive timing curve or have boosted compression, they can help make the spark more consistant and give you a bit more 'headroom' in tuning decisions.

The other thing that should be mentioned is MikesXS has had some quality issues lately, so you may want to look elsewhere for coils. Dyna also make replacement coils very similar to the Mikes units (in fact, the Mike coils are probably cheaper knock-offs of the Dynas) that can usually be found for less money if you shop, and do come with a warranty...

[SFerinTEXAS]

After hearing someone discuss high-output ignition coils and finding a set on mikesxs.com, question is: why would a person change from stock coils to the hi-performance set?

We were asked a question. My comments and those like from crazy steve are the type of information relative to the question for the uninformed to make a decision.

Much better than "YOU GOTTA GET SOME" typical replies. To that I add that if anyone questions the OE coils integrity and/or can not test all aspects of them to satisfaction . Then upgrade. But if trying to correct an unknown run problem and new coils does not fix it then lesson learned and don't wine.

[bikerphil]

JMHO, don't waste your time with cheapo Chinese made MikesXS coils, spend a few Xtra $ and get some reputable ones, a coil failure will ruin your day if you are far from home. Newer OEM (doesn't have to be Yamaha) 3 ohm coils are a good choice too.

Sferin, Hotter spark = cleaner combution = better mileage = smoother power.

[fredintoon]

After hearing someone discuss high-output ignition coils and finding a set on mikesxs.com, question is: why would a person change from stock coils to the hi-performance set? Question 2: I heard a rumor of a speedometer that would fit my '82 XJ-1100 that goes up to 160. Any comments/info on that? Any help would be appreciated.

Hi Pegasus,
there are Dyna coils on my bike because it came that way. Why did the PO change them?
1) The stock coils &/or their built in plug wires were shot?
2) Trying for better performance?
3) Bragging rights?
The PO I got the bike from was not the PO who swapped the coils so I couldn't ask him but #1 is the most likely.
As to the speedo upgrade, that looks like a whole deal of work.
Face it, the only time you'd need a 160mph speedo is when you are racing.
And real race bikes don't have speedos, they just have a tach.
Just as well the speed-Nazis didn't think to limit tachs back to 6,000 rpm, eh?

[natemoen]

JMHO, don't waste your time with cheapo Chinese made MikesXS coils, spend a few Xtra $ and get some reputable ones, a coil failure will ruin your day if you are far from home. Newer OEM (doesn't have to be Yamaha) 3 ohm coils are a good choice too.

Sferin, Hotter spark = cleaner combution = better mileage = smoother power.

the dyna coils are cheaper than makes XS anyways.