You may find it necessary to add the power commander in some cases if it stalls. The factory fuel map is lean during cruising and in some cases with the tip it might stall. Did not occur here but others have seen this observation
It appears more people need the power commander anyway to get rid of the factory lean condition causing other issues mostly engine and exhaust heat.
The Wolverine is very lean at idle, but this proves that the tip is increasing flow to the exhaust system, enough apparently to cause hesitation during start up.
Tinken, have you blocked off the AIS? It will make it show lean at idle and part throttle when the AIS opens to allow more air into the exhaust. It doesn't open at WOT.
It's a useless piece of crap to appease the EPA. It injects air into the exhaust port to burn off excess hydrocarbons. The YXZ has it too and Graves motorsports came out with blockoff plates for it.
It's an Air Induction System mixes air into exhaust gas; the Yamaha AIS is directing air into the engine for exhaust cooling. This also aids the catalytic converter & meeting emissions. It's supposed to aid proper combustion in a stock system. Once you change anything, get rid of cats, etc. it's pretty much useless, & will cause popping of the exhaust during decel. Something that needs to be blocked off and re-tuned.
Fuel map will be off from actual AFR. Probably not enough to matter. Disconnecting will not throw any codes but not sure if it leaves in open or closed state. On the R1, YZF and so forth there are machined block off plates. I think there is a AIS delete kit for the raptor too.
The extra air will make the popping on decel worst just like an exhaust leak will.
Thanks for the information Deeyoh. I didn't know there was an ais valve on the engine. Machined block off plates are the way to go. It will change the maps a little for sure and something I will address. I have a couple of work arounds I can do with mapping which I will try later today on Boss's Wolverine.
I was able to finally get Boss's Wolverine tuned without modifying the ais valve. He has reported no deceleration popping, better starting and better power through the powerband. I will tune with the ais blocked off as time permits.
I'm not sure it really did make a difference, maybe, but not in the way I originally thought it would. The ais pumps air into the header to aid in burning excess fuel which would show a false reading across the lambda sensor. Originally I thought it might be showing a leaner condition than what really existed. Common sense would dictate the retraction of fuel. The opposite was actually the case here. I boosted the fuel up to 10% in a nonlinear envelope down the fuel path which smoothed out the power band, possibly ending the mid-range stalling issues. I made several other changes to the beginning and wide open throttle areas for reliability as well, including an extra timed addition of fuel for whiskey throttling. Ignition timing changes are less abrupt and safer now. So over all, it was a combination of changes which made the difference.
In my experience, the lambda sensor should be used as a guide to fuel tuning, but should never be considered an absolute. There is so much more to tuning engines than just placing a number in a map. Anyway, I would love to dive further into theory of fuel tuning, but we'll save that for the fuel tuning thread.
So, has anybody with a stock 708 (no tuner no pcv no ais block off) had problems after installing the hunterworks tip?
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