So I just hit 18k. Doing another inspection. at 12k, no adjustment was necessary at all. At 18k, every valve is at max clearance. I can't find the old notes from the previous inspection and previous adjustment, so I can't recall how the valves have worn. At 6k I adjusted to near maximum clearance. 12k miles later, I've got pretty minimal wear. One exhaust valve is getting tight and both intakes are wore equally tighter by like... 10% of the allowable range. Not bad at all.
At 20,000klm mine measured (mm) I: 0.24/0.25, E: 0.44/0.42. I decided to re-shim and are now at I: 0.26/0.265 E: 0.425/0.41
I also had my valves checked for the first time at 12,000 miles and no adjustment required. I next time I will have them checked will be 36,000 miles as my mechanic recommended.
I have to share the same experience as Shawn. I have checked mine twice now. Once at 12K and once at 32K. Spot on both times.
Two observations: 1. Obviously the top end of these engines are well designed with so little adjustment required; and 2. The longevity of these engines appears to be as good as anticipated with quite a few riders above 50,000km / 30,000 miles by the sound of it. As far as I'm aware, no one around here has reported having to replace rings, pistons, cam chains or valves from normal wear and tear (excluding the obvious but rare 'lemons'). Makes me wonder why the 'other' similar performance singles don't seem to be quite as low maintenance, reliable or long-lived...
Was reading a post on AdvRider thread titled "why Thumpers have a relatively short life span " where a Dakar owner (post 131) reported 110,000 miles from his Rotax 650 and it had never been opened up. Also read elsewhere where a BMW 650 owner claimed over 200,000 miles with only parts apart from normal service items changed was new water pump. Since the TR650 is based on the same engine (but with modifications for the extra 10 HP), I'm hoping the TR650 engine will last as long if looked after.
1. Obviously the top end of these engines are well designed with so little adjustment required; and 2. The longevity of these engines appears to be as good as anticipated with quite a few riders above 50,000km / 30,000 miles by the sound of it. As far as I'm aware, no one around here has reported having to replace rings, pistons, cam chains or valves from normal wear and tear (excluding the obvious but rare 'lemons'). Makes me wonder why the 'other' similar performance singles don't seem to be quite as low maintenance, reliable or long-lived...[/quote] My Terra has already 50.000km. somebody knows when do you have to change the distribution chain inside the engine?. someelse to change?.
Overkill, I shall not be thinking about mine until 50k Km and then only if it is noisy, bad starting or loses performance, why bother?
I monitor highway fuel economy & backfiring on deceleration. If one decreases & the other increases, a good tell-tale to look at valve adjustment.
