Valves

It's been a long time since I've written anything on this blog; my other one has taken up most of my free blog time lately (Claret and Blue in My Blood had 179,000 unique viewers in January alone!), but I finally got back to thinking about bikes a few days ago.  And while I know the weather is closing in again, the recent sun and slight warming is enough to get my motorcycle hormones running again.  It's still too cold to do any serious off-road stuff for a while, so I'm concentrating on getting the bikes ready for when the weather warms up a bit.  One thing I've done is to install a 12 volt charger for my iPhone and GPS on the DR.  But the bike itself needed some TLC. 

I bought the DR just before Christmas 2010 with 9,8000km on it.  I changed the tyres taking off the "Deathwings" as they are euphemistically called and put on some Conti TKC80's.  I loved them, but after 5,000km the rear is looking the worse for wear and may not last past May, so I've picked up another.  The handlebars were upgraded; the oil has been changed twice, a rear rack installed and an rock bash-plate has been installed.  After riding it for 5,000km last year, I changed the oil again in the fall and made a mental note to find out when the valves needed adjusting.  Looking online, it was suggested they should have been adjusted at 2000km then again at 12,000km and every 12,000km after that.  Well, with the odometer at 15,000km, my eyebrows raised a little: it was over due.  Then I read the warnings about delaying valve adjustments.  The gap between the valve and the piston shrinks with wear, so that eventually you either get a catastrophic coming together or the valve gets too hot and distorts, refusing to seat and then finally falling into the bore.

Nice.  The information did say a thousandth wasn't too bad to be out, but any more and you're asking for trouble.  Yikes.

Well after washing all the mud off the bike - you don't want any of that stuff falling in the the engine - downloading the on-line workshop manual, I popped off the tank, seat, panels, TDC inspection port bolt, crank bolt, and valve covers and took a look.  First you have to rotate the fly wheel until you see the "T" mark symbol in the hole.  This you do with a socket wrench.  The first time the mark flies by, you have to look at the valves and see if the whole head is moving.  If it is, continue rotating until the T spins another 360 degrees and appears centred in the inspection port.  The valves should all be closed, and there should be gap between the tappet and the valve stem.  This is different for the exhaust valves than the intake valves.

Then comes the next little surprise.  The valves need a special "adjustment" tool to adjust them.  After several unsuccessful forays to purchase a cheap substitute, I realised I had something that would do, and although not perfect, it saved me $50:

For the DR, the recommended intake setting is in the range of 0.003 - 0.005 inch.  They were perhaps a little tight, so I lubed the 0.004inch feeler gauge and firmly slipped it into the gap.  It took some persuading, but it went.  The 0.003 went easily and the 0.005 didn't go.  The manual recommended both intakes be done at the same time, so that the feeler gauge friction could be better judged and balanced between the two.  

 As you can see, the intake valve lock-nuts are easy, but the inverse Robertson head adjusters on the valve stems confounded Canadian Tyre, Lordco, Baker Supply and Napa Autoparts.  I was damned if I was going to purchase it from Spunkies: that's a front tyre!!

So good news, the intake valves were within spec and actually needed opening just a fraction.

But the exhaust valves were a different matter.  The manual recommends between 0.007 and 0.009 thou for them.  So, naturally, I went to stick my .008 thou feeler in and it wouldn't go.  Nor would my 7 thou or my 6 thou or my 5 thou...  True to form they had tightened, and I was lucky I had bothered to check.  I was half thinking that it was all a load of rubbish, and I'd check them in the fall of 2012.  So I opened the lock nuts and adjusted them with my handy dandy 1/8 inch spanner and noted that a 10 thou wouldn't go in, so the widest they could be was 9 thou; a gauge that I don't have. 

I'm guessing the valves were not readjusted by the previous owner at 2,000km...  They certainly weren't done by me at 12000km!  The book mentions that valves that are too wide are OK, noisy, inefficient and potentially safe as long as the engine oil is kept topped up, but tight valves are a big no no. 

I'll be checking the valves every fall or 12000km whichever comes sooner now.  It's quick and easy and not worth the risk of neglect. 

Paul