Airbox breather update – (almost) a year on

Aprilia Caponord ETV1000 Rally-Raid airbox breather drainJust gave the Capo motor a service. No drama, everything went according to plan. I just thought I’d share a couple of pics of the inside of the airbox – with the modified breather – straight after the air-filter assembly was lifted. No cleaning, no Photoshop ….. just as it looks after 5,354 miles. The throttle butterflies, velocity stacks and idle air control valve (IACV) are all perfectly clean.

The extended drain tube from the airbox (down below the oil filter casing) held about a spoon full of oil when drained and what can be seen in the photo was only a light coating in the bottom of the airbox. One sheet of kitchen towel had that as clean as a whistle in a few seconds. Since doing this breather modification I’ve ALWAYS run the oil level to the HIGH mark on the tank. So without the tedious job of removing and cleaning out the complete airbox, it was a pleasure to simply replace the Athena air filter and button everything back together.

Aprilia Caponord ETV1000 Rally-Raid airbox breather drain

Check Valve AP8104251 – symptoms

Aprilia Caponord ETV1000 Rally-Raid AP8104251vacuum check-valve exploded viewA couple of folks have asked what the symptoms where that prompted the replacement of the check valves (AP8104251). Well, for a while I’d had an intermittent ‘cough’ or momentary stumble when lifting the throttle off idle …. maybe once every twenty times or so. More than enough to make your heart skip a beat when you think she’s about to stall just as everyone’s powering away from the traffic lights! Other than this annoying habit, everything in the garden was Rosie. Or so it seemed.

I’d cleaned and rebalanced the throttle bodies and all the vacuum hoses and inlet rubbers were perfect as they’d been replaced – but it kept happening. In the end with nothing much else to go on, I’d pulled the check valves and found them both to have failed.

Since replacing them, I realise there were other symptoms – very subtle –  and the sort of thing you adapt to without realising it.

  • Reduced engine braking. This was really noticeable within a couple of miles after the valves were replaced – Engine braking  is certainly  stronger now
  • ‘Burble’ from the exhausts on overrun. This is greatly reduced, especially at low RPM
  • Eratic idle during warm-up. The idle became lumpy at 65°C then smoothed out again by 70°C – now stable throughout.

With a few hundred extra miles under the belt, it’s fair to say that the intermittent off-idle stumble has well and truly gone which is great of course …. but I do miss that bit of ‘Burble’ on the overrun! So if you have idle issues and any of these symptoms ring a bell, then take a moment to check the valves as well as the usual old favourites – IACV, vacuum lines and inlet rubbers. You might be surprised.

MCCruise control revisited

Aprilia Caponord ETV1000 Rally-Raid MCCruise CIU throttle servo cablesWhile the Caponord was stripped for the vacuum check-valve replacement, I decided to get my act in gear and finally, once and for all, unequivocally ….. Sort out the MCCruise control/throttle cables. Last year I relocated the CIU (Cable Interface Unit) to the left hand side of the throttle body. This had pros and cons ……….. The upside was a lighter feel on the throttle grip, the downside, the Servo/CIU and CIU/Throttle body cables were overly long and the Servo cable fed into the CIU from the wrong side. However, the cruise was working perfectly and so it became one of those ‘mañana’ jobs!

Well today is that tomorrow! First I jotted down a list of what had to be done:

Aprilia Caponord ETV1000 Rally-Raid MCCruise CIU cable interface unit1. Make a spacer to fit onto the side of the CIU. This is to move the throttle cable adjuster further out and make the inner cable a better fit on the spool.
2. Drill new cable holes in the CIU so it can be rotated 180° so the Servo cable enters from the rear not the front as is the current arrangement.
3. Shorten the CIU/Throttle cable while allowing for the new spacer at the CIU – 350mm down to 190mm.
4. Shorten the 1,150mm Servo cable to a more reasonable 750mm!

I have to say here and now that I do like learning new skills or adapting old ones to suit a new task. I also have to admit that in a good few years on this Earth, I’ve never made up or adjusted Aprilia Caponord ETV1000 Rally-Raid throttle cablethe length of clutch/choke/throttle cables before! So time to adapt the electronics soldering skills and brush up on required technique courtesy of the Internet. Now I’m not going to bore you to tears telling you how to do it – there is tons of advice on various websites/YouTube. Suffice to say, sort out the duff advice from the good, have the right equipment to hand and practice, practice, practice  …… do the job once and do it right! All the cable bits and pieces I needed came from Venhill in the UK.

By late afternoon everything was buttoned up and the cruise control recalibrated after the throttle bodies were rebalanced, fault codes cleared and TPS reset via TuneECU. As the sun faded behind the hills I cracked open a cold beer happy with how the day played out …. Time then to put the tools away and get back to revising for the next Amateur Radio Exam!

Aprilia Caponord ETV1000 Rally-Raid MCCruise controlThe MCCruise has been installed for approx. 25,000 miles and worked perfectly throughout. The CIU was relocated because the initial location proved to be problematic – causing slight binding of the throttle cable. This meant that the cables supplied in the kit (as specified by me) were now the wrong length and the orientation of cable entry into the CIU was wrong.This is not the fault of MCCruise, what they sent is what I asked for! Should anyone else wish to go down this route I will of course be glad to provide notes/measurements etc so a kit will be a simple bolt-on job.

Vacuum check-valve …….. part2

Aprilia Caponord ETV1000 Rally-Raid check valve AP8104251The new vacuum check-valve (AP8104251) arrived yesterday and today, while the rain poured endlessly from a depressingly black sky I set about swapping out the bad one on the front cylinder. Just to be Boy-Scout ready, I’d also made sure to have some new hose and stainless steel click-clamps to hand – just in case! Getting the old one Aprilia Caponord ETV1000 Rally-Raid AP8104251 failed check valveout is a real trial of patience and dexterity believe me! Here is a pic of the old valve cut in half and you can see that the valve has broken up completely.

 With the valve cycling anywhere between an estimated 11-73 times a second depending on RPM, it looks like the 0.5mm thick valve flaps suffer from fatigue and  rips develop where the material flexes most. The valve doesn’t completely fail until the flap is ripped away as my other (rear cylinder) valve is testimony too. That valve flows in one direction but also a very small amount in the other and when Aprilia Caponord ETV1000 Rally-Raid AP8104251 valve stress testviewed end on, light can be seen through the valve flaps leading me to think that rips have already begun. So now another new valve is on order and I guess I’ll make a note to check these again in 15K miles or so, it’s easy and quick to do – simply pucker up and suck or blow! 😳

Aprilia Caponord ETV1000 Rally-Raid AP8104251 one way valve sectionOh and I’ve been asked a couple of times …. why not use a cheap Ebay ball-valve replacement? Well it seems to me they’re just not designed to cycle rapidly, a ball/spring valve may well be susceptible to the same phenomena as an engine valve train at high rpm – valve bounce/float. Of course in the real world it may make no damn difference what so ever and I’m just a sucker for buying genuine Aprilia parts! 🙂

UPDATE

Aprilia Caponord ETV1000 Rally-Raid check valve AP8104251Second (rear cylinder) valve replaced and all now in perfect condition. In this case the valve was leaky as it had a tear down one side – so a partial rather than total failure. It also seems that these parts were upgraded some time ago, this looks like it’s a modification to the plastic body …. on the old one the case is simply presses together, on the new one it is welded. Maybe they had instances of the cases coming apart in service, who knows.

Pucker up and suck or blow …. your choice!

Here’s todays little quiz ……

  1. What’s this?
  2. Where does it go?
  3. How many are on YOUR bike?

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Of course the smarty-pants among you will scream out the answers to 1 & 2 in double quick time – it’s a check-valve or none-return valve and it fits between the throttle body and clutch in the vacuum line. Excellent stuff, spot on …… but question 3 …… one valve or more than one? Hmmm.

Here’s what Aprilia show in the parts manual (click for photo of matching engine) …..

Aprilia Caponord ETV1000 Rally-Raid pneumatic vacuum clutch and one way valve

The front cylinder throttle body port has nothing but a piece of clear hose and a bung – the manometer/VAC gauge test point. All the slipper-clutch hose/valve assembly is ONLY attached to the rear cylinder throttle body port and TPS port. This may well be fine and dandy for an 01-03 bike.

But if you have a Rally-Raid or an 04-onward bike, next time you’re under the fuel tank/airbox take a good look at the front hose …… my guess is you’ll have a ‘T’-piece and more black hose disappearing downward below the mire of cables and wires running alongside the frame. Now this might be no surprise to you, but it had me scratching my head for a while I can tell you! 😕

And this is what I’ve got on the Rally-Raid (click to enlarge)……

Aprilia Caponord ETV1000 Rally-Raid slipper clutch pneumatic vacuum lines and check valves

A second complete set of pipes AND a second check valve connecting to another ‘Y’-piece. Why do this? Well this is my hunch, guesstimation, call it what you will ….. the 01-03 Capo has I believe a clutch pack that is 43.6mm thick, the 04-08 is 44.9mm thick. A difference of 1.3mm – in other words the valve springs will be compressed an extra 1.3mm on later bikes and that means a little more spring preload for the vacuum system to overcome when getting the clutch to slip, hence the second set of connections to improve the vacuum – 2 cylinder are better than 1! Also, two sources of vacuum from cylinders running out of phase (60° remember) may well help smooth out the pulses you can sometimes feel through the clutch lever. It simply looks like Aprilia modified our blessed Caponords and just didn’t bother to update the parts manual.

So what’s all the hullabaloo, why rip this poor little thing from the Capo’s delicate innards? Well the long and short of it is that one of them is pooped, shot, completely knackered ….. where air should only flow one way, it flows happily in both. Looking at the defective duckbill valve reminds me of Daffy-Duck cartoons, the ones where Elmer Fudd rearranges his bill with a shotgun! No worries, simply order a replacement …….

……. Aprilia part no AP8104251   Just make sure you’re sitting down when you look at the price! 🙁

I’ll shortly open up a new page with some more 3D images to try to better illustrate how the system is operating at different stages and how to go about testing the valves and what to expect.

Oil in the Airbox …..fixed!

You may (or may not!) have read the post a couple of months ago – Fixing a few Capo niggles. That was where between Continental trips, the original air-box molded connection for the crank-case vent was drilled out and a new 90° bulkhead coupling and Aprilia Caponord ETV1000 Rally-Raid extended airbox drain tubepipe fitted to drain any oil into the front of the airbox, well away from the throttle body and IACV (Idle Air Control Valve).

Now with the Caponord seriously (+1,000 miles) overdue a service, I got stuck in and removed the tank ready for plugs/air filter. I admit to being really pleased to see no oil what so ever in the upper part of the airbox and only a tell-tale smear in the front section. A syringe sucked what oil there was from the drain tube – approx. 5cc @ 3,000 miles WITH the oil tank filled to the HIGH mark.

Previously it didn’t seem to matter where the oil tank level was, oil kept getting thrown into the airbox and sucked down into the throttle body. Look closely at the design of the airbox and you see the ‘fenced’ in area (red) around the velocity stacks – and of course, the two slots in the stacks (arrows) for excess oil to drain through.

Aprilia Caponord ETV1000 Rally-Raid new crankcase drain inside the airbox

It’s pretty obvious then that Aprilia/Rotax EXPECTED regurgitated oil – and tried to ensure it was fed back to the engine and burnt. Unfortunately that isn’t always the case and when some bikes are left on the side-stand oil manages to get over the ‘fence’ and muck up places it shouldn’t!

Of course a little hot oil can spread a long way and look far worse than it really is ….. I guess it just niggled the hell out of me each time I lifted the airbox lid. In hindsight it’s one of those quick jobs I wish I’d done years ago.

Down the tubes

Boy doesn’t time fly. It only seems a few days ago (weeks really!) I got here and already I’m packing again to head back to the UK on the Capo. Other than a check over, the Capo’s as she came back – unwashed even.

Aprilia Caponord ETV1000 Rally-Raid vacuum pipesBut this morning, with only a couple of days to go, events took a turn for the worse. Off we went for a little run around and suddenly, out of the blue, she’s running rough at idle …. Cough, cough, snuffle and splutter. In all honesty, only one thing came to mind – vacuum pipes.

Anyway it didn’t spoil the day and we got home with no drama (she ran fine at higher rpm) and 15 minutes later the tank was lifted … and here’s the culprit. One split vacuum hose on the front cylinder. So for now a generic bit of fish-tank plastic line has been press-ganged into service and a couple of nice new silicone hoses have been ordered of Ebay – one blue, one red. Colour coded vac pipes for each cylinder!

After 12 years and with almost 80,000 miles now on the clock I guess it’s probably a job that was getting towards the top of the to-do list!

All teeth aren’t equal!

Aprilia Caponord ETV1000 Rally-Raid Sunstar 16T front sprocketA good few year back when I had a Triumph Trophy 1200, I had an issue of excessive noise from the chain/sprockets – especially on the over-run. They were almost new and as far as I could tell, it was correctly tensioned. It drove me mad for a week or so, until I decided to try changing out the front sprocket, why I can’t remember, but it worked.

Now the same issue has raised its head on the Capo. The Sunstar front sprocket was fitted at the same time as the chain/rear sprocket, so about 3,500 miles ago give or take. Gradually I began to get a noise – mostly on the over-run that progressively got louder as the miles piled up. Once again, chain tension was fine, the slipper block in perfect condition – no obvious reason for the noise. What had changed?

Aprilia Caponord ETV1000 Rally-Raid front sprocket - Renthal & SunstarThe only difference I could think of is the make of sprocket. I’ve always used Renthal since I got the Capo, so the Sunstar was a step away from what I know and trust. Back to a Renthal 407-525-16P it is then.

And …….. all the noise has gone! Yes a good run around yesterday afternoon including annoying the hell out of an R1200GS rider desperate to give me the slip, proved once and for all that the Sunstar was the culprit. It certainly makes me think that the profile of the teeth may well have something to do with it, maybe that’s the reason Aprilia fitted a sprocket with cush-rubbers?

Fixing a couple of Capo niggles

Aprilia Caponord ETV1000 Rally-Raid airbox / crankcase vent modificationOne niggle that has wound me up more than anything about the Capo over the years, is its unerring ability to regurgitate oil into the airbox – apparently no matter how much or little I fill the oil tank. In the end, enough is enough, time to do something about it.

So this is it, remove the molded spigot/structure into the airbox and replace with a new low-profile 90° coupling and pipe to dump regurgitated oil into the front section of the airbox, from where it can be drained off via the extended drain-line down by the oil filter. Hopefully no more lumpy idle and intermittent ‘cough’ coming off idle after extended (12Hrs+) runs at motorway speeds from the vented oil draining down into the throttle bodies. A better fix of course would be to build a trap before the airbox that would allow oil to drain back the way it came while still passing vapour into the airbox. That’ll wait until winter, for now I’m hoping this will work good enough.

Aprilia Caponord ETV1000 Rally-Raid clutch oil jetsSecondly, and I don’t mind admitting when a change to the Capo doesn’t work – I’ve gone back to the #60 clutch oil jet from the #40. Why? Simply because the benefits were outweighed by the losses …… yes the #40 jet made the initial 1st gear selection go from ‘CLONK’ to ‘clonk’ but it also buggered up all subsequent gear changes, gone was the silky smooth shift that I’d had with the #60 jet. In the end I would say that if your Capo shifts gears smoothly and doesn’t have an issue selecting Neutral, then leave well alone. I’m sure for those with no jet, a blocked jet or a nasty gear shift this may well be a worthwhile modification, for me I’m glad to have the old slick-shift gearbox back again.

Cool running Capo

Aprilia Caponord ETV1000 Rally-Raid Agip Permanent Plus coolant (Antifreeze)After fiddling around with the cam chain tensioners, it was time to refill the coolant system – something Aprilia say to do every 2 years and MotoA has successfully neglected for almost double that! The handbook says to use either Agip Cool or IP Ecoblu. While Ecoblu is still available, the Agip coolant has apparently been superseded by Agip Permanent Plus and Agip Permanent Spezial ….. and wait for it ….. they’re about to be rebranded again as ENI Antifreeze Bike P and ENI Antifreeze Bike S. So which one do we need for the Capo? Well the ENI website says Bike S, while AF1 recommend Permanent Plus (Bike P), so I ordered Permanent Plus before the headache-of-confusion got any worse!

Aprilia Caponord ETV1000 Rally-Raid Agip Permanent Plus coolant (Antifreeze)What’s the difference? One is blue and one is red …….. but it goes a bit deeper than that! I must admit that the heady and scintillating world of antifreeze has past me by for most of my adult life, my knowledge pretty much stopped at – it’s green (mostly) and it stops my engine exploding into an ice block during winter-woolly-wearing time. Oh no, it seems that is most definitely NOT the end of it, our aqueous boffins have been brewing up a positive Smörgåsbord of antifreeze variants and as you can guess only some are suitable for our precious two-wheel companions. If you want to fry your brain with antifreeze techie stuff, have a read here. Otherwise it simply comes down to the difference between the two Agip products – Permanent Plus (Blue) is hybrid technology and good for 2 years while the Permanent Spezial (Red) is OAT (Organic Acid Technology) and good for 5 years – hence the ‘long-life’ tag.

Aprilia Caponord ETV1000 Rally-Raid coolant expansion tankBut in the end, whatever you buy just make sure it’s good down to -40c and nitrate free and pre-mixed or mix it to a 50/50 solution. Remember that over time the corrosion inhibitors will be used up and the solution will slowly become acidic. Consider buying a PH tester for a couple of pounds/dollars to check the PH level in the radiator when doing a service, ideally it should be 8 or higher when new. If the PH is below 7 then the coolant definitely needs replacing before the acidity starts to eat away at the engine.

So now the Capo has had a nice flush and refill with Permanent Plus and the spreadsheet has been updated to give me a gentle nudge when it’s due to be changed again, rather than the fill-it-forget-it method I’ve used to date!