Dyno run brings bad news
 

The previous owner of my 2009 XTR removed the snorkel and fitted a stage 1 filter. I bought it in great condition at 2500 miles. Now, at 4500 miles, I'm wondering how it's running, as I'm not sure about these mods without changing the fuelling.

So this morning I took the bike into my local dyno centre for an air/fuel run. My expectation was that it would be a little lean, but nothing to worry about, as that seems to be the consensus on the forum: stage 1 filter and snorkel removal is OK without more fuel.

After an hour, the tech comes back clutching pieces of paper and starts explaining things. His view, in a nutshell, is that at low throttle it's so lean it's almost off the chart. His opinion is that if the bike is used regularly at low throttle or cruising, that it's lean enough to eventually cause problems. On the plus side, power does seem up a couple of bhp on the default XT660 chart. I mentioned a 2000-mile trip coming up and the tech's view was not to use the bike for the trip without sorting the lean mixture.

So I have 4 options.

1) Leave it and hope it doesn't go pop.

2) Buy a standard OEM filter, take the performance hit, and hope for the best. Maybe pay another �35 for a dyno run to see if it's at least better. Keep an eye out for an old snorkel.

3) Buy Kev's fuel and O2 mods. With all respect to Kev, I had hoped to leave the bike as stock as possible without resorting to the DIY wiring that one finds on used vehicles. The stock running of the bike doesn't bother me too much.

4) Cough up the �500+ for a Power Commander. Their usual price is �300 including fitting, plus �150 for the custom map. However, they said the inclusion of the O2 module in the XT kit would probably add cost at all stages, so expect �500-�600. Yikes!

Needless to say, I'm pretty gutted. I certainly didn't want the bike with less performance, and I did expect it to be on the safe side of lean. I'll wait for the quote on the Power Commander option and then see what to do.

:(

Here's the dyno chart.
https://lh6.googleusercontent.com/-D.../s912/dyno.gif

:eek2:That is rediculously lean between 3000 and 4500rpm!
You'll need to either go back to stock for now (which is still rather lean in that area), or get a Kev mod/O2 controller sharpish. You really don't need to spend big bucks on a PC to sort this out; the only significant benefit of a PC is you can "fine tune" everything in small increments with a custom map. The PC is the perfect solution, but you'll have to ask yourself is it �400-500 better?

Doesn't the Kev mod simply enrichen the mixture by X at all times (in open loop)? Wouldn't that mean that the setting that sorts the lean range would then cause the 5500 to 7000 range to run incredible rich at around 10:1?

Yes, in a way, but it is adjustable. The O2 controller is more what I was thinking. Looking at your problem, it is controlling the closed loop that would see the best results.

I considered removing the snorkel removed but I seen an ad for DNA filter mods and I noticed that that they recommend a restrictor being fitted to reduce the size of the aperture into the mouth of the air filter when not using a power commander,
I have fitted a Kev's Mod, Pipercross airfilter and a GPR exhaust, so instead of removing the snorkel I shortened it considerably but the aperture into the airfilter has remained the same I have set the Kev mod to 9 oclock and WOW what a difference (brilliant).

Hope this helps

I don't know if the DNA filter is what's made the bike so lean, but I have a K&N version I could try. Unfortunately, each dyno run takes about 3 hours of my time and �35, so I could spend a lot of money swapping filters and blocking the air intake before I get any safe results.

Pleiades could be right that the O2 controller alone would sort my problem, but I'm looking for Kev to spot this thread before I take any action. If I spend �70 on the O2 controller, plus another �35 on a dyno run, and it's not solved the problem, I've spent �100 of the money that could have gone on a PC and custom map.

If I could find a used snorkel online I'd go back to stock for now, but it seems people must hang on to them. I wish the previous own had kept the one from my bike!!

One big question was the AIS blocked off for the Dyno run?

The Dyno graph only shows 100% throttle run, what was the part throttle run A/F ratios at? Can you get me the Dyno run files so I can have a look at them?

Thanks for getting involved, Kev.

As far as I know, the AIS was not unplugged or blocked. The tech didn't mention AIS at all, and I've certainly not done anything to it. The bike has the standard cans so I think AIS is untouched. Why??

I've left a message asking the question though, and also requested the dyno charts and information on the part-throttle run. I'll update when I hear back.

This is why you have shown abnormal low end leanness results on the Dyno but the real facts are your bike is not lean at all in the low end.

AIS stands for Air Intake System, the system injects air into the exhaust system after the exhaust valves, the Dyno will see the extra injected air as a lean mixture. You need to block off the AIS every time you want to check the A/F ratio otherwise you will always get false A/F ratio readings. If you disconnect the connector at the AIS the valve will remain open^& the whole map will show over 16:1 A/F ratio from idle to rev limiter.

Any good Dyno operator should know this basic prerequisite before a Dyno run.

They won't give you all the Dyno graphs as there would be many of them, ask them for the Dyno run files they can Email them to you, I will decrypt them for you & will be able to tell exactly what your bike is doing on the Dyno.

Thanks Kev. I've not heard back yet but I will as soon as I hear anything.

Do you know on what criteria the AIS works? Is it temperature dependent, revs dependent etc.? Is it likely on the graph I posted that the AIS would be operational up to 5000rpm and then not? Or is it more likely that the entire graph is skewed by 2 and that it is actually fine at low revs but rich higher up?

Despite having a mania for having other bikes dynoed I've never bothered with my XT,it came with Akra's on it and nothing else,I fitted a K+N and then a DNA2 still with nothing done to the fuelling I could tell it was running lean just by the feel but short of riding down the motorway on the stop for 20 miles ran good enough.

Sent for Kev's fuel mod and it was obviously blowing more fuel in made a world of difference and I see no reason for you not to do the same,how much is the mod now? but expensive it ain't and a 2 minute job to fit just takes a few runs on the road to try different ajustments and it's a good'un.

What you have to make your mind up about are you in it for the long haul and a PC etc or not as the case may be and go for a Kev mod.

I've tried both a PC with the above and the snorkel out ran even better but the icing on the cake are the holes in the airbox .

I won't comment too much on your post you seem a little frazzled but you can sort an XT out for far less than the crazy prices your quoting

Thanks for the advice. Apparently the tech is waiting for advice back from Dynojet so I still don't even know whether the AIS was blocked.

The reason for my "frazzled" state, which I do confess to :) is that having done a highlands tour a few weeks ago on my K1300S, I'm heading back on a trip to the Isle of Skye 2 weeks from today on the XT to see whether I can sell the K13. With an estimated 1500 miles in the week, including 600 miles of motorway, I could have done without the tech's advice of "I wouldn't take it that distance with the A/F like that". I don't claim any real technical knowledge so I rely on others for advice. When I'm close to skint and someone tells me by bike will be damaged by the trip I have booked a few days away, I feel frazzled. :)

Fingers crossed it will prove it be an error on the tech's part, or easily resolved by Kev's technical wizardry. :)

The AIS mainly runs below 5500RPM at any throttle opening as it does not affect the combustion A/F ratio, it is there to burn off the hydro carbons after the exhaust valve for emission control & as you now know will affect the A/F ratio reading down stream of the exhaust valve.

Why on earth would the Dyno tuner need to contact Dynojet, very strange statement from him. If he had blocked off the AIS he would have said straight away yes it was blocked off. I have spent many hours on the Dyno with these XT660 & have only seen that type of leanness when the AIS is not blocked off.

I called the dealership this morning and was told that the bloke's gone off to collect a bike, but is still waiting to hear from Dynojet.

I said "All I want right now is a simple 'Yes I blocked it' or 'No I didn't'" so I can stop worrying and throw those graphs in the bin.

Apparently they're aware of AIS-type system and usually clamp the pipes. Fine, but that still doesn't tell me whether they thought to do it on mine.

Very frustrating.

Thanks again for the help, Kev.

The bottom line you've been 'HAD' I have a bit(lot) to do with bike trade I see dozens of bikes K+N's open pipes they(punters) wouldn't know any of the fuel mods or a PC so long as they've got a hole in their back side never mind an engine map or changing oil this side of 20,000 miles!!!,and they all keep running like Swiss watches.

But when the panic subsides let me know what you need I'll loan you snorkel etc till you can get one,you'll be coming past my house going to Jockland junction 7 M6 we can even talk k12/300's!!,I thought I'd seen you name else where.

Thanks mate, I appreciate it. I'll see how things go over the next couple of weeks.

Well the tech that did the dyno run finally called back. Not that I'm any the wiser.

He says, "The AIS is just a form of pair valve. Not disconnecting the pair valve isn't essesential. It WILL be lean at the very start, but only for the first few rpm. Your XT was lean for 2000rpm. That's not because of the pair valve. If it had a lean blip at the start I would ignore it, but yours doesn't - it's lean for half the rev range. The guy at Dynojet also says that in the case of these bikes, the O2 Optimizer is as important or more so than the map."

So, he reckons it's lean for too long to be the AIS. I have no idea. I asked him about part throttle graphs, and he said that they do part throttle as part of the full mapping process, but not for a simple A/F ratio run. Again, I don't know if this is important.

End result - I am discarding the dyno results as I don't know enough to interpret then. The dyno bloke, and the guy from Dynojet apaprently, claim it is not essential to bloke the AIS, and that the AIS is not behind my lean graph. Kev, who I respect, says that's not true. All I know is that I'm �35 lighter and don't have a clue whether I have an issue or not.

For my next bike, I am going to check the forums first to make sure that no ****** mods it at all!! :)

Hamslay, see my recent post 'Kev Mod feedback'. I fitted the mod the other day and where the bike was feeling very lean for the first half of the rev range, it now feels completely normal. It's also adjustable, so you can tinker with the settings until you get the mixture you like/need. I assume the mixture is enrichened all the way through, but there are certainly no ill effects at half-throttle and up. It runs like a champ at all revs now. Perhaps the map is more sensitive to air temperature (which is the parameter being altered) at lower revs in any case?

It comes to just over 45GBP, and 20 minutes to fit, so to me if you have a long trip coming up it's a no-brainer. Your engine will be safe, even if it might use a bit more fuel. I'm 99% satisfied with my setup now (still have some final trimming to do), and wouldn't consider paying 300+ for a PC.

Just my €0.02.

(ETA: the mod comes with a block-type connector which works fine, but if you prefer a non-DIY appearance, you can always solder the device into the wires and heatshrink to finish it off. That's what I plan to do when I get a minute.)

OK. I just bit the bullet and ordered Kev's mods on ebay. Fingers crossed they turn up quick enough for me to fit at least the O2 controller before the trip. I tried to contact the forum member in the UK that was meant to have an unwanted controller but he didn't reply. Shame.

Dyno run brings bad news
 

Regardless of whether or not you ever get to the bottom of AIS/dyno run mystery, you WILL notice a big difference with the O2 controller - it is money well spent.




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I hope so. Thanks mate.

Mine was delivered to my door on the 6th day after ordering. Not too shabby for a journey of 12,000 miles (Aus to GB).

If they said you don't need to block off your AIS system I would be taking my bike to a dyno center that knows what they are talking about, utter rubbish mate, part throttle tunning is very important you load the dyno brake to simulate a load & watch part throttle A/F ratios, what is the use of only looking at the A/F ratio at 100% throttle, the part throttle opening A/F ratio's are one of the most important readings as this is where we ride all the time.

One thing I do agree with is that the O2 closed loop circuit needs to be contolled as well to get these bikes to run well, that is why I recommend a fuel mod + O2 controller.

Thanks Kev. It does seem it was a bit of a waste of time with these guys. I was a bit pissed off when they finally phoned after 3 days and said "We didn't block the AIS because you don't need to on a simple A/F run".

Oh well, hopefully your mods will be here soon and will sort everything out.

Blimey it really sounds that you have been had mate, or at the very least they give very shabby service and dont seem to know what the heck they are talking about. Ask them for the money back cos they dont know what they are doing. And find someone else!!! Good luck, I have the Kev fuel mods and my bike was transformed!!!

The mods will make sure you don't damage your motor in anyway.

And they do say that "a little knowledge is dangerous", indeed......