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Author Topic: 690 (New model) Wafer check valve, air pump and evap cannister  (Read 264 times)

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Offline GW

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  • Bike: KTM 690 Enduro
    Location: Western Cape
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Hi. First post ever here. My new model 690 Enduro has a couple of oddities that my previous 690, which was a 2014, did not have. I thought I would share this and as I go along let you guys know how I decided to live with/deal with these add-on gizmos. My previous  had a twin spark cylinder head which, with the inlet temp monitoring, FI, narrow band Lambda and exhaust cat was deemed efficient enough to pass emission standards at that time. All I did on that bike to restore its self pride as a performance bike was to fit an fmf exhaust canister and Twin Air flat foam filter (from Wayne Puzey) on the standard air box with an open type fine mesh cover. Of course it was very powerful.

This all new motor has additional cylinder head mounted balancing shaft and the cam operating directly on the inlet valves, and only one rocker arm extending across to the exhaust valves -so perhaps those issues of failure are sorted who knows? Time will tell.

But the reason for this post is firstly, to reveal my discovery of KTM's (and Husky's) addition of a wafer check valve behind a cover on the cylinder head and secondly, the evap canister/ fuel vapour contol from the fuel tank.I know the 701 has had this motor for a year or two but this is all new for the latest KTM 690.

On the wafer check valve cover is an outside pipe connected to a rubber tube which leads to a little 12v air pump which draws fresh air via another rubber tube from the air box and it (the pump) tries to introduce this air into the exhaust port via a built in channel in the cylinder head towards an inside point just where the exhaust header bolts on. The wafer check valve allows air to be drawn/pumped in to the exhaust during the rarefaction part of the exhaust pulses and especially during vacuum scavenge (I think). This addition of fresh air into the exhaust header helps to oxidise unburnt fuel and make the bike pass emission tests after the exhaust gases pass through the large oem cat exhaust. (Also it makes the top section of exhaust run kind of hot; this is in the section where the lambda monitors for lean/rich).

I took the large stainless steel heavy oem cat- containing exhaust off and fitted my fmf pipe. It wasn't straight forward but nevertheless easy for me as I can do the required fabrication mod which was to make it Momar clamp friendly and adjust the top bracket. And I put my same flat Twin Air filter onto the airbox. I thought all would be fine but no. No.......it wasn't.

The excellent inflow of air and the performance exhaust with the additional air being pumped into the exhaust makes for quite dramatic popping and backfire on beginning to tap off, deceleration. I think this is because there is now dramatic scavenge, and maybe combined with valve overlap there is some inlet cycle mix just managing to hammer into the exhaust header and this, combined with the hot header and extra air pumped/drawn in through the wafer check valve caused a detonation or two or twenty. (Maybe)

So I knelt down and looked at the pipework, there's a lot of it but actually quite simple and neat..... And I left it all in place. (for now). BUT: I made a same shaped 1mm in-between plate to close the check valve whilst still leaving the cover plate in place on top. (I cut up an old junk desktop cd drive enclosure for the thin steel plate) We were in lockdown at this stage so the test ride had to be a shopping trip and I went to an unnecessarily far shop in the Tygerberg hills. The backfire was gone and the light popping that remained was just that happy crackle that a big single has. I did fill up in Durbanville and that caused its own problems.

The second issue ie: the fuel vapour control system reared its head. The bike started fine at the garage and shortly afterwards I made a roadside stop to call home. When I started up to get going again the bike stalled immediately when I cracked the throttle open to let out the clutch. With a Ffffrrrpoptt! decomp valve sound. Twice.

Back home I knelt down (again!) next to the bike and discovered that the overflow from the fuel tank travels downward via a Y connector to a thick closed-at-the-bottom collector pipe (which is joined to the bottom of the Y section) and then up and all the way forward to a charcoal filled canister and then another suction pipe goes from the plastic cylinder out to a 12v solenoid valve, then to the throttle body manifold side. When I removed the stopper at the bottom of the thick pipe below the Y-piece quite a column of fuel ran out onto my hand. Also, I popped the vacuum pipe off at the throttle body/manifold side and even there the inside of the thin pipe was wet with petrol. so the canister was not really able to remove condensed vapour fully and it caused a fuel rich vapour to be sucked in, stalling the motor.(I think) If the fuel tank is not full you may not experience this as much but off-road there is a lot of shaking and fizzing of petrol  which will find its way down that collector pipe.....And I left it all in place (for now) BUT I removed the stopper from the collector pipe under the Y-piece so the overflow is once again an overflow and I put in an internal block within the thin vacuum pipe near the throttle body. So even when the solenoid valve is open there is no suction.

Another important item was needed from the shops, this time Olive oil from a farm shop on Tygerberg hill. WOW. The bike is now absolutely different; smooth idle, ridiculous snap and wicked wicked acceleration.a very different bike. Not sure if this is an interesting read, but at least it demonstrates that the very high performance motor is not at all happy with all the secondary air system paraphernalia and it is there just to pass the EU tests, probably very frustrating for the design engineers at KTM and Husqvarna. At another stage I will do the removal of the pipework, valves etc. but for now it is functioning exactly the same. It is basically a very new bike so for obvious reasons.......

 

Offline teebag

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Re: 690 (New model) Wafer check valve, air pump and evap cannister
« Reply #1 on: May 01, 2020, 06:57:07 pm »


Mine mysteriously fell off, onto the garage floor.


Sent from my iPhone using Tapatalk
 

Offline GW

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    Location: Western Cape
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Re: 690 (New model) Wafer check valve, air pump and evap cannister
« Reply #2 on: May 01, 2020, 09:21:08 pm »
Ja, those are pretty much all the bits that should fall off  ;). I'll see about the Lambda at a later stage though. I left my 2014 with the O2 sensor in and I was happy enough. :thumleft:
 

Offline Dirt Junkie

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Re: 690 (New model) Wafer check valve, air pump and evap cannister
« Reply #3 on: May 02, 2020, 08:04:11 am »
Proper 1st post :thumleft:
2003 KTM 640 adv,  Aprilia RS 250, Yamaha YZ450F, 2014 KTM 690, 2010 KTM 690R, 2011 BMW F800GS, Yamaha XT600E , 2012 KTM 250 SX-F , KTM 400 EXC, Kawasaki  KLR650, Honda 125 estorm, 2012 KTM 300 XCW, 2008 KTM 690, 2006 BMW G650Xchallenge

Current:  2006 KTM 640 Adv, 1979 Suzuki SB200
 
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Offline BuRP

Re: 690 (New model) Wafer check valve, air pump and evap cannister
« Reply #4 on: May 02, 2020, 10:35:20 am »
@GW ,

Goto Rottweiler's website, they probably have (a) kit(s) to remove all those gizmo's - to make it more reliable & run better, not to get more power!
Power comes from de-catting (done) and intake improvements (done a bit).
If your bike has the large carbon-canister sitting behind the radiator then by removing this huuuuge 'blockage' you will improve on cooling also!

Btw, correct summary indeed.
Oh, be careful what you buy from Rottweiler, because some of their stuff is and costly and not really necessary to actually buy.... you've done a few things already yourself  ;)
Whilst there perhaps also look into the sidestand switch removal - which you also can do yourself (you do know the magnet needs orientating correct?).

Enjoy this bike!  :thumleft:
Sparta MC50, 46 other 50cc's, Garelli Tiger Cross, Jawa 250, Kreidler RS (plated), Kawasaki S1 250/3, S2 350/3, H1 500/3, H2 750/3, Suzuki GT380/3 - 10 year gap - KDX200, BMW 1150GS Adventure, Honda CBR600RR, Honda XR650R 2007 & 2003, Honda CRF230, Yamaha BWS100, BMW F800GS Adventure, Husqvarna 701 Enduro 2018, KTM 790 Adv R 2019, KTM 2020 XC-W TPI 300 Six Days, KTM 2014 500 EXC-W Six Days, KTM 790 Adv R Rally 2020
 
The following users thanked this post: GW

Offline Rough Rider

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Re: 690 (New model) Wafer check valve, air pump and evap cannister
« Reply #5 on: May 02, 2020, 03:01:20 pm »
 :sip:
Current rides: 2015 WR250F / 2016 690R / 2017 701SM
 

Offline GW

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  • Bike: KTM 690 Enduro
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Re: 690 (New model) Wafer check valve, air pump and evap cannister
« Reply #6 on: May 03, 2020, 10:43:33 am »
@GW ,

Goto Rottweiler's website, they probably have (a) kit(s) to remove all those gizmo's - to make it more reliable & run better, not to get more power!
Power comes from de-catting (done) and intake improvements (done a bit).
If your bike has the large carbon-canister sitting behind the radiator then by removing this huuuuge 'blockage' you will improve on cooling also!

Btw, correct summary indeed.
Oh, be careful what you buy from Rottweiler, because some of their stuff is and costly and not really necessary to actually buy.... you've done a few things already yourself  ;)
Whilst there perhaps also look into the sidestand switch removal - which you also can do yourself (you do know the magnet needs orientating correct?).

Enjoy this bike!  :thumleft:

It might be a long while before we can get any deliveries of online purchases, but yes, I can do the mods (proper aluminium cover plate etc.), myself in my workshop. ...And once I get the correct resistor values to mimic the loads on the air pump and evap solenoid I will be sorted. (They have very low actual values; around 20 and 26 ohm). There are conflicting values on the internet, some say 22Kilo ohm some say 2.2Kilo ohm. If I used actual values the resistors will need to be wire wound 10Watt as the "work" they will be doing will only be as little heaters as opposed to the pump/solenoid doing actual mechanical moving pumping/valving work.

The Rottweiler mimicking resistor dongles look biggish so maybe they are the 10Watt type? Maybe someone will actually measure the bought kit resistors. I found and jury-rigged a 2.2k resistor temporarily just out of interest  and it did not work, the yellow (tiny engine icon) light came on.

Of course, I am just being impatient I guess. We can't do any trips so what's the point except that it relieves boredom to tinker with the bike.....? Thanks for the encouragement. I would prefer to be discussing this while sitting around a fire chewing on a braai chop of course.
 

Offline BuRP

Re: 690 (New model) Wafer check valve, air pump and evap cannister
« Reply #7 on: May 03, 2020, 11:46:27 am »
No wirewound power resistors GW, just metal (blue) quarter-Watt types .... at least these are what was inside my 701's kits.
They are worked inside connectors hence may seem bulgy - but aren't.
Besides, would be ridiculous to shed heat by emulating the removed power devices, and 10W is a lot, you know surely?
If you've got resistors lying around by all means experiment, you only want to find the sweet spot (band actually) in which the diagnostics are 'happy'.
When you do best to play with temperature as well, ditto water, to see if the system 'stays' happy.

Come over for a braai?  :thumleft: :P
Got dop too  ;)
Sparta MC50, 46 other 50cc's, Garelli Tiger Cross, Jawa 250, Kreidler RS (plated), Kawasaki S1 250/3, S2 350/3, H1 500/3, H2 750/3, Suzuki GT380/3 - 10 year gap - KDX200, BMW 1150GS Adventure, Honda CBR600RR, Honda XR650R 2007 & 2003, Honda CRF230, Yamaha BWS100, BMW F800GS Adventure, Husqvarna 701 Enduro 2018, KTM 790 Adv R 2019, KTM 2020 XC-W TPI 300 Six Days, KTM 2014 500 EXC-W Six Days, KTM 790 Adv R Rally 2020
 

Offline Dwerg

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Re: 690 (New model) Wafer check valve, air pump and evap cannister
« Reply #8 on: May 04, 2020, 01:31:51 pm »
Most of that went way over my head. I'll come back and re-read this until I understand some of it  :lol8:
Current: KTM 690R
Previous: KTM 790ADV, 640ADV, 950ADV, 250XCW BMW F650GS Single, F650GS Twin, F800GS, G450X, R50/2 Honda CRF450X, CRF230 x 2, VFR400 NC30, Z50 Mini Trail Yamaha BWS100 x 2, LB80 Chappy
 

Offline BuRP

Re: 690 (New model) Wafer check valve, air pump and evap cannister
« Reply #9 on: May 04, 2020, 07:49:31 pm »
I'll come back and re-read this until I understand some of it  :lol8:

I'll repeat the basics Dwerg:

Come over for a braai?
Got dop too

 :P
Sparta MC50, 46 other 50cc's, Garelli Tiger Cross, Jawa 250, Kreidler RS (plated), Kawasaki S1 250/3, S2 350/3, H1 500/3, H2 750/3, Suzuki GT380/3 - 10 year gap - KDX200, BMW 1150GS Adventure, Honda CBR600RR, Honda XR650R 2007 & 2003, Honda CRF230, Yamaha BWS100, BMW F800GS Adventure, Husqvarna 701 Enduro 2018, KTM 790 Adv R 2019, KTM 2020 XC-W TPI 300 Six Days, KTM 2014 500 EXC-W Six Days, KTM 790 Adv R Rally 2020