Not for those weak of heart or mind
So I decided that before I added any more kilometers on my Wee's odometer (39,300 km) I should check the valve clearances. Yes, it's a tad overdue, I admit. I've successfully repaired single cylinder small engines in my previous lives. So, I wasn't daunted with the prospect of working on a 2-cylinder motorcycle engine. How difficult could it be? :mrgreen:
Stripping down the bike to get at the vital parts was tedious, including completely removing the radiator. Hell, it was time for a flush and recharge of coolant anyway. Messy, but not all that difficult (once I figured what had to come off the bike). :thumbup:
Removing the valve covers required careful attention to prevent damage to the delicate gasket - entirely reusable if you don't damage it. Checking the valve clearances was no biggy but I took care to follow the instructions in the service manual (Page 2-8,9) for rotation of the crank and using the proper timing marks. This is very important for getting proper measurement. :fineprint:
My measurements showed that all eight valves were at the very bottom of the allowed clearance ranges. I couldn't risk riding another 1,000 klicks and I didn't want to have to do this job again for a long time. But, I needed to get this job done so I ordered the Hot Cams kit from Rocky Mountain which arrived in five days which is very good cross-border service (FedEx). :hurray:
When the time came to remove the cam journals and cams to get at the tappets I knew I was going to be severely challenged. In order to release even one cam from the cam chain it was necessary to release ALL of the tension provided by the cam chain tensioner. Following the advice of NTM and Black Lab I removed only the tensioner bolt (not the complete body - which could NOT have been done on an ABS equipped Wee anyway without pulling the engine). Front tensioner came out easily enough but the rear one required a combo of extenders on a ratchet wrench attacking from the rear wheel area. It was necessary to completely remove the rear wheel to even see the tensioner body. :jawdrop:
I made a big mistake. :yikes: I chose to start on the rear cylinder because I thought it would be the easier one to work on. After being confounded with the results and freaking out when, while turning the crank, I saw that the chain was skipping over the cam sprockets because I had not yet replaced the tensioner bolt. I was too upset to do anymore work that day so I left it all there in the shop and started again the next day.
This time I resolved to read ALL of the relevant pages in the manual and marked up the really essential points with a hi-liter like a cramming college kid. Reason prevailed and I FINALLY understood the intricacies of crank and cam lobe positions and why you have to start with the front cylinder. Those of you who are planning to do this job must read manual pages 3-99 through 3-106. This is required reading. :fineprint:
At this point the project began to take its toll on my patience. I found it was very difficult to replace the tensioner release bolts into their respective bodies because there is precious little room for the hands of grown man to manouver. The rear one in particular. There is a lot of extra gear and plumbing in this area for the ABS system. Only when I detached the rear shock at the top and dropped the swingarm a tad (it only dropped a half inch before bottoming) did I finally get enough room to attack the tensioner body. Because of the angle of the body it proved extremely tiresome getting the bolt to catch the first threads. This was by far the most difficult part of the whole job. :furious:
I'm happy with the results. No pistons crashed into the valves. All the clearances are now in the mid-to-upper numbers in the ranges. I figure it will be a while before I will need to check again. But, given all the drama that this project created, I'm not sure I EVER want to do a valve adjustment on my ABS Wee again. That will be done at my local dealer - if I can afford to pay them a princely sum. :jawdrop:
Many thanks to NTM, Black Lab, Greywolf and others on this forum who provided useful tips and suggestions. :thumbup:
