saab9k wrote:
07roadstar wrote:
Your going to have to explain what this person said because when i read it it may me a bit confused too. Here is his quote about the 42 carb and only the 42 not the cv carb most have from the factory. Not stepping on your toes here.

The 42 does require the use of a Dyna ignition but, contrary to what some believe it does not need the TPS connection when a Dyna is used... It is just an extra expense that has no measurable or proven difference in ride or performance.

I think you would need it anyways, right!

that pic is my bike look alike

Well lets do that again.

Nice bike you have there too saab9k!!

texasscott1 wrote:
Ok, I'm back and I'll try to explain although Erbman has done a pretty good job.

Back when cars used distributors there were two separate mechanical advance mechanisms. The flyweights which advanced the ignition according to engine speed and the vacuum advance which added in more advance during light throttle operation. The engine would run without the vacuum advance connected just not as well during light loads. During full throttle the spring in the vacuum advance mechanism overcame the low vacuum signal and shut it off. That old fashioned system worked very well.

Now the TPS - It can be thought of as the electronic equivalent of the old vacuum advance. At low throttle openings the TPS signals the igniter that the load is low and more timing advance can be added over and above what has already been added according to engine speed. Disconnect the TPS and the only advance the timing will get is whatever was determined by the engineer to be the maximum the engine can sustain at full throttle at any given engine speed..

Like Erbman said the engine will run the same at full throttle without the TPS but you'll give up the efficiency and extra fuel mileage available at light throttle loads. Which is probably where most of us spend the majority of our time anyway.

Any of the aftermarket ignition boxes are the same, if they use the TPS signal them maybe they can help performance but if not then it would seem to me to be a step backwards.

Questions?

Thank you Scott.

I found this link to the Dyna 3000 instructions -

http://www.dynaonline.com/skins/downloads/instruct/D3K7-3.pdf

It states right in the instructions that the timing curve varies smoothly between the closed throttle and the WOT curve with the TPS. So if, like I've seen recommended, you leave the TPS hanging locked in the closed throttle position you probably will have to use a lower curve to prevent pinging at WOT. If, on the other hand, like I've also seen recommended you disconnect the TPS then the Dyna will default to the WOT curve - just like the stock ignitor.

The big advantage with the Dyna is the ability to change curves and to raise the rev limit so the next shift is higher in the power band.

The testing I've read about was with the TPS either locked in the Closed Throttle position or disconnected and with the Dyna as with the stock unit those two options would lock you in one curve or the other. The advantage of having both curves when needed would be lost.

Oh, and they use the same kit # up through 2007.

Texas Scott wrote: Importance of TPS 1 Day, 5 Hours ago
Ok, I'm back and I'll try to explain although Erbman has done a pretty good job.

Back when cars used distributors there were two separate mechanical advance mechanisms. The flyweights which advanced the ignition according to engine speed and the vacuum advance which added in more advance during light throttle operation. The engine would run without the vacuum advance connected just not as well during light loads. During full throttle the spring in the vacuum advance mechanism overcame the low vacuum signal and shut it off. That old fashioned system worked very well.

Now the TPS - It can be thought of as the electronic equivalent of the old vacuum advance. At low throttle openings the TPS signals the igniter that the load is low and more timing advance can be added over and above what has already been added according to engine speed. Disconnect the TPS and the only advance the timing will get is whatever was determined by the engineer to be the maximum the engine can sustain at full throttle at any given engine speed..

Like Erbman said the engine will run the same at full throttle without the TPS but you'll give up the efficiency and extra fuel mileage available at light throttle loads. Which is probably where most of us spend the majority of our time anyway.

Any of the aftermarket ignition boxes are the same, if they use the TPS signal them maybe they can help performance but if not then it would seem to me to be a step backwards.

Questions?


Samson wrote: now this subject has been beat to death.... but you 2 guys still have to prove it to be a fact to Shane of S/S CUSTOM CYCLES.

FAREWELL BOYS AND GIRLS.....
me makes no difference either way

Samson, My intention here as always been to provide information to the members that is correct especially when I see something that is contrary to statements made by the manufacturer. Shane seems like a really nice guy but there are options other than what he recommends that, in my technical mind at least, are a better choice. So I tell folks.

I remember a post here a while back from a member that was experiencing pinging when trying to run the Dyna at the curve most use. I don't know if anyone came up with a fix so I'm wondering if he was running with the TPS locked in the closed throttle position and trying to run at wide open throttle with the higher timing curve.

Working at a Yamaha dealership gives me access to a lot of technical information that consumers never see. I read a LOT not only for my own information but to help the new Techs we have. That's how I found the float level update that was published back in 2000 which for whatever reason was never published in the discussion forums.

Sorry if I offended you. Maybe someday I'll discover something that helps with a problem you're having.