I’ve got old motorcycles, so I fix stuff.
Now I’m lucky (I Think) that these old motorcycles are BMWs, and can sometimes go for long periods of time without requiring much in the way of sacramental ministrations from me.
But no machine made by the hand of man is perfect. BMW Motorcycles certainly are not. So in a garage where the average age of a motorcycle is currently 36 years, stuff is going to break.
I’ve talked about how — after skipping my normal warmup process and pushing my Flying Brick motor too hard and far too fast — I’d come back into the garage to discover two thirds of a newly liberated exhaust manifold stud.
I’d hoped to have an independent BMW mechanic buddy of mine attend to the failure, but his circumstances seemed to keep his attention distracted by a whole passel of other things. He’d gone miles out of his way to convince me I could affect the repair, and after a while, despite my candid mechanics self appraisal, I began to believe I could do it, too. My recent change in economic circumstances made me susceptible to arguments to frugality, as well. So I headed down to my local Harbor Freight, bought a set of reverse drill bits, a set of extractors, and some industrial grade penetrating oil, and set about the fix, man.
Let it be noted, that any story that begins with the phase “So I headed down to my local Harbor Freight…” has already formally set the stage for tragedy.
I pulled the lower belly pan from the left side of the LT, and eyeballed the broken stud. It turned out to be the number 1, frontmost cylinder, in the farthest forward position. Of all the studs, it has the best access from directly below, not being fouled by exhaust headers, stands or any other stuff.
I laid down a few layers of heavy mover’s blanket down on the garage floor, got my drill and my LED worklight and dove in.
I got one of Grandpa Wadi’s mechanic’s punches, and nicely centerpunched the broken stud end. I got my reverse drill bits, chucked a fine one up in my Bosch 12v drill — a very precise, small, light tool — and executed a nicely straight hole right into the middle of the stud. I took the next size up, then the one the size after that and enlarged the initial pilot. I then hosed the whole operation down with the penetrating oil, and left the job for the next afternoon. For a bit of delicate work — especially considering the exhaust was still in place – this was going pretty smoothly.
The next day I resoaked the stud in pentetrant, and after leaving it soak for a few, took an extractor, threaded it into my pilot hole, and immediately became that guy — Bang! the extractor tip sheared cleanly off.
Please supply your favorite stong oath of any culture here.
After some deep and embarrassed thought, I called George Mangicaro at his shop – Gridlock Motors – and confessed my manifold sins and inadequacies, and begged for mercy. Or if he couldn’t supply mercy, at least better tooling and equipment to unmess the mess I’d helped make worse.
I pulled the rest of the belly pan so George wouldn’t have to deal with that. While the lower bodywork was stripped, I installed a set of new spark plugs since access was now trivial. Plug readings on the ones that were removed indicated that inside that precious engine, all was operating optimally.
I had a nice ride taking the LT down to Warrenton. The Brick’s smoothness and ability to deliver big torque at highway speeds never gets old.
Here’s hoping George’s better preparation, training and skill translate directly into better luck.
The R90S continues just to be a stone. After a recent ride, I finally seized the opportunity to get some clean oil into the old girl after the drowning she took last summer while the big teardrop build was going on. In a good half hour I changed the oil and filter and she ran noticeably quieter and more smoothly with motor oil having lower water content in the cases.
Case closed, your honor.
So with one motorcycle fully ready to ride, I went to the back of the garage and set my sights on the /5. The poor old thing had been running poorly. For a bike that I’ve ridden since the early 80s, and which has 180K or so showing on the clocks, running like crap was something the bike has never really done, so my attention was fully engaged. I assumed that being thoroughly drowned in four or five months of Maryland Monsoon, combined with a little benign neglect, had produced this unfortunate turn of events.
It would turn out to having nothing to do with that at all.
I undid the two bronze wingnuts that secure the rear of the bike’s fuel tank, then popped it off and sat it in the tank saddle fixture I have on my workbench. One has to love a motorcycle that can have its fuel tank removed in under three minutes.
I pulled the left carb intake tube, then the left airbox cover. There was a very old K&N reusable gauze filter installed, which, given my recent education in their usefulness as filters, was removed and unceremoniously binned in the shop trash. I threw out with it two fairly good size mud dauber wasp tubes that had also been in the airbox. I used my LED micro flashlight to look into the right side intake, just to make sure that there were no other oddball foreign objects sitting in the carb’s intake venturi. There’s weren’t, so I dropped a stock air filter in the housing, and buttoned everything on the intake side back up.
I disconnected the battery’s negative lead, and then prepared to pull the front engine cover. With my 3/8 ratchet and allen head bit the three bolts that secure the cover were out promptly, and then I pulled the engine cover free from the rubber seal that secures the tach drive in place. Immediately, it was clear that something was not quite right.
As soon as the cover tilted away from the case, oil began pouring out onto the exhaust crossover. I am, you may have observed, somewhat precise in my use of language. This, it should be noted, was not ‘seeped’, ‘dribbled’ or ‘ran’ — this was ‘poured’. The shop manual and troubleshooting pictures I referenced a short time later will show a little oil collected on the engine case lip under the points plate and wryly observe that ‘this may be evidence of a cam seal failure.’ This wasn’t that. If the theoretical maximum volume of the entire points cavity is, let us say, 5 fluid ounces, there was at least three if not four full fluid ounces of motor oil in the /5’s points housing.
As I scrambled to find something really absorbent, I kept thinking the same thing over and over.
I don’t know how it ran.
Since my whole theory of the case had now been thrown summarily out the window, I was on the hunt for more data. I pulled both spark plugs — sure enough, both were dark, sooty, indicating weak spark, which is certainly what they had with the points operating submerged in oil.
I finished the work that could be completed without the new parts I was going to need. I pulled the left cylinder head cover to check the valve clearances. Rocker end gaps were in spec, and both valves were a little tight. I passed on retorqueing the studs — at 180,000 miles and 65,000 miles since a major top end overhaul, I’m pretty confident that this engine is stable and ‘run-in’. I opened up the clearances in both valves, replaced the cover, and then rotated the engine through 360 degrees and attended to the other side. On the right side, rocker endplay was also fine, and only the exhaust valve was out of spec. A quick adjustment, replace the cylinder head cover, and it was Gojo and laptop time.
A little Internet time later I had a line on a new seal, a seal puller, a set of new points, and some allen head screws to replace the flatheads on the timing plate, which after 46 years, are a little worn.
Looking at the timing cover, it was clear that oil had been working its way down onto the front of the engine – there was a fair bit of dirt and oil accreted on the bottom of the cover. There were also six or eight carbonized Marmonated Stink Bugs in the cover. Another mystery – I have no idea how they could have found their way in there.
When the postman finally comes, we’ll remove the points, timing plate, pull and replace the seal and then put new points in and retime. I’ll end up having to completely resynch the carbs, as all of the richarding around I did to try and get the bike to idle will have thrown things off horribly when there’s good spark and airflow again.
Given how far this old motorcycle has carried me, setting it right — given how little is required — is the very least I can do. I’ll keep her rolling and ready to ride again for as long as fortune and luck hold out. More than that is a road too far ahead for me to be able to see.