Just 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.
A 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.
out 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.
viewed 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! 😳
Oh 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 – 
pipe fitted to drain any oil into the front of the airbox, well away from the throttle body and IACV (Idle Air Control Valve).
A 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.
The only difference I could think of is the make of sprocket. I’ve always used 
Secondly, 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.
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 