Flash,

Sorry I haven't gotten back to you on this sooner. I've been using every spare minute I can, trying to get all the photos formatted, CD-burned, and sent off to Gram for the big Engine Teardown Article series (over 100 photos). I'm very excited.

Anyway, about your question(s) on the Speedstar ignition module thingy: After looking up a few things, and talking with DK Montgomery (DK's Powdercoating), here's what I've come up with:

1). The SS ignition will set your spark timing to WOT, if the TPS is unplugged (as best DK and I can remember).

2). The SS ignition will leave your engine warning light blinking, if the TPS is unplugged.


Anymore questions--ask away.

Hope this helps a little.


Thanks for your interest.

Thanks Randy, yep you are right if your dealing with the stock ign, but the compitetion ignition shuts off the engine lite even with the tps disconnected.. that was the main reason I went with the yamaha ign, instead of the dyna..as at the time I was unsure if the dyna would turn the lite off..looking forward to seeing the engine build. now if I can just talk you into financing it, I'll be good...

Flash,

Really (the light goes off with the SpeedStar ign)... That's interesting. Both DK and Joel (Odo) were sure the light would stay on with that ign.

Cool . It's not often I get to say, "I told you so"--especially to those guys.

At any rate, you should be good to go, if you want to install a VOES. The input from the TPS wires should work fine with the that ign module. I think you'll get a little better grunt in the low end. Should be enough to notice, for sure. It won't be dramatic, mind you, but it should definitely be noticeable. Gas mileage should pick up a tick or two, as well.

Hope this helps.

Well I can promise you that the comp ign module from yamaha, did shut down the engine light... the light still works when you turn on the key,, then it goes out... I guess my question was, since the module seems to ignore the signal from the tps, would it ignore the signal from the voes as well... in any case, I am looking forward to the engine build, I have a lot of questions about the bottom end being able to handle the extra cubes...compression..etc....

NOW I UNDERSTAND YOUR CONFUSION! Sorry to be so dense.

The Dyna shuts off the engine light, too. Actually it isn't ignoring the TPS voltages at all. It's just smart enough to recognize that the TPS has been unplugged, and since this module is made for competitive use (like racing), it figures that you know what you're doing, and you've unplugged the TPS on purpose. So it shuts that dash light off for you.

However, if voltage signals start going to it from the TPS (because you've installed a VOES), it'll know how to handle that just fine, too.

Not to worry, mate. All is well.

Does THIS response address your question a little better? If not, keep asking.

Well that sounds like a good thing. .. I do have a question tho,, many actually, but I will hold on to those until I see your newest project.. but when you went to the big bore..(113ci), did you need to modify the cases any? I have read somewhere that if you go too big, you will need to cut some of the case bore.. which makes sense.. just wondered if 113 is the majic number....

Yea, the new Tech articles cover all that stuff--108ci, 110ci, 113ci, 122ci.

I do have to be careful what I say the the articles, though. Don't want to upset the feelings of others who've made different decisions. So let me say a few things NOT in the articles, in addition to a few things that ARE.

Bottom line answer: Anything above 110ci, the cases must be bored. Some say the safe limit should be 108ci, since the cylinder sleeves must be made thinner for the 110ci to fit--allowing for heat expansion (so I've been told). There's no HP difference between 108 & 110 anyway (according to Skip Dowling, owner of OE). It's just a numbers thing.

None of the R* big bore kit companies make their own pistons. The market is WAY to tiny. There are three suitable pistons for our engines: Westco (or Wescco or something like that) which Barons sells, JE which PR & OE use, and Omega which NR uses.

But I think the question is much more involved and interesting than just, "How big of a hole do you want to make?" I think it's much more about piston weight, shape, and materials. I think emphasizing THAT makes for a much stronger, longer lasting, more rideable bike.

It's pretty simple to pull the cylinders, swap them for bigger ones (without thought to the piston confiuration), put in some bigger pistons and a bigger carb, and go. But most guys are pretty disappointed with the results. There's more power, but not THAT much more. So they end up also swapping cams, swapping valve-springs, going to bigger valves, and porting their heads. The results of all this, however, are often that the motor lacks strength unless RPM is kept high, carbon builds quickly unless the engine is run hard (often), and extra vibrations come from piston weight varying too much from stock weight (Note: there will be more vibration anyway, due to the higher compression).

Personally, I've been through all that: building a racing motor, bragging about the laundry list of components, street racing other bikes to prove my point, getting tired of having to fiddle with tuning because of carbon or other issues, and then ending up selling the bike because it's just not relaxing to ride anymore.

I ride for relaxation, fun, sightseeing, commuting, and only occasionally: thrill. I also really like working on bikes. But I wouldn't want to make my priorities (or opinions) your's. That's just how I see it.

It'll be a good three weeks or more before the engine info is online. It's a lot of info. So if you get anxious before that, send me a personal message. Maybe we could arrange for a phone call or something.

Hope this helps.

I have a question about which VOES to use. My engine has PR pistons in stock bore size, PR cams & springs, and an HSR42. plus I am using the DYNA 3000 ignition module. Your advise will be appreciated.

Fasrnu,

The 4" Hg, Drag Specialty# 2101-0009 unit should work well. Your HC pistons alone, put you in the 4" category. Add to that, the cams (higher lift, longer duration equals more volume into the cylinder), and you're solidly into the 4" category.

I have big bore, but stock cams and valves. The 5" works well for me, but I'm thinking of swapping with a 4" so I can compare the two (on my engine) side-by-side.

If you're in doubt, get the adjustable VOES. Don't have a part number for you off hand; you could look in the Drag Specialty catalog if your supplier can't come up with a # for you. Just be sure you don't end up getting a MAP (manifold air pressure) unit by mistake (unless you WANT to go that way).

Let me know if this doesn't address your concerns. Thanks.

Well it's after christmas, I figure I can link up the tps to the hsr fairly easily as it does not have to go more than a half rev..I can use a linkage to the throttle shaft and tie it in..I don't know if it will make a difference with the yami comp ignition mod, but yami sells the comp mod to folks that have a stock carb,,so it's either that or the voes,