Tech Day: Top End Removal for a BMW Airhead

This past saturday, the 10th of November, I rode over to Brook R's home in Arvada, Colorado to watch him and Dick P, the Colorado Air Marshall work on Dick's 1972 R75/5 Airhead.

One of the four rods which hold the left side cylinder/head had become stripped you see, and they were going to show whomever attended the tech day how to repair that.

It was only myself and a young fellow by the name of Jason that showed up to be elucidated.  I'd seen Brook do this once before but it never hurts to see such things more than once!

 Brook is describing the oil passage flow into the head

from within the engine.

Dick had rented a special jig from Northwoods Airheads in Golden, CO to do the repair.  It ensured that when he drilled and tapped the hole for the helicoil insert, that the drill bit and tap tool would be straight and "square".

 Installing the round portion of the jig, which allows it to be

centered on the cylinder's hole in the engine case.

It also supports the connecting rod once installed.

 A shot of the main part of the jig, to show how it

slides along the remaining three cylinder rods.

Dick had already removed the stripped rod, as you can see above.

 Jig in place, tube sleeves are mounted and tightened to

hold the jig firmly against the engine case.

 Drilling out the worn threads.

 Tapping in the new threads prior to inserting the helicoil

which will form the new threads for the rod.

 The helicoil just before insertion, Dick had coated it

with Red Loctite to ensure it stayed in place in the long run.

It was at this point that things went slightly askew.  The helicoil was inserted a little bit too deep and while Dick tried to back it off, the helicoil somehow jumped a thread and got stuck.

 The red stuff is in the loctite, you can see (hopefully)

that the helicoil is in too deep.

Much head scratching ensued.  Several attempts were made to try and get the helicoil bit that had jumped a thread to lift and lie correctly but no go.

The session ended with a stop as it was getting a bit late in the afternoon, while Dick and Brook sent off queries to the jig manufacturer describing the problem and seeing if there were any suggestions/solutions.

I rode back home and got to the usual sunset watching spot with Brigitta but the light was to show better further south due to clouds as Sunset approached.

I rode Brigitta instead to the church parking lot near the house and got these shots instead:

 Pikes Peak, America's Mountain

I checked with Brook and Dick on Monday and they'd solved the issued with the liberal use of Acetone to melt the Red Loctite and a jeweler's screwdriver that he successfully fit under the 1st thread so it could be bent. Then a pair of needle nose pliers were used to grasp the bent thread, and turned counter clockwise to eventually unwind the helicoil insert from the hole.

Brook went ahead and successfully installed a different helicoil into Dick's motorcycle engine and now all is well.  The loctite is curing and will be ready for this coming weekend when they'll reinstall the cylinder and new heads which Dick had procured.  Not sure I'll be be able to attend though, still, I'm glad the issue with the helicoil was fixed and it sure was a learning experience for me.

2016 Denver Area Airhead Tech Day

Beautifully sunny weather here in the great state of Colorado shone down today on the annual gathering of local area Airhead riders who gathered once more at Dick Paschen's place for a sharing of knowledge, telling of tales, kicking of tires and even some wrenching!

Dick is the Colorado Air Marshall for the BMW Airheads Club and has played the gracious and knowledgeable host for many years to this event.  He makes a great pot of chili, puts out coffee and water, and can be seen taking part in almost every repair operation that got underway.

Pretty good turnout in terms of riders, perhaps 60% were the expected "older" riders who've been around Airhead motorcycles for many years.  What was gratifying to see if lots more of the "younger" riders who are entering into the Airhead world to seek knowledge and help with their vintage motorcycles.

 One of the first arrivals was this beautiful R90S in the famed Daytona Orange Colors.

It came in for some front brake work and a check of the wheel bearings.  The motorcycle had

sat unused for 20 years overseas, and is now being brought back online by its new owner.

 Here's Dick Paschen doing the initial examination of the front wheel.

 Not every airhead rider was a gray-haired gentleman!

Good to see younger members to someday carry on the torch.

 Speaking of younger members, though technically an oilhead, this R Nine T

motorcycle next to Fiona shows much things have changed for 

BMW motorcycles.

 Some airheads came in on the back of pickup trucks, this one owned by 

Cort, got all sorted out while at the tech day, he left a happy camper.

 Some airheads needed a bit more "work" shall we say.

This particular airhead had sat under a tarp out in the elements for ten years!

Radar, the gentleman in the black cap and dark blue long sleeve shirt 

wondered how much of the engine would still move!

Some penetrating oil was administered and a short time later, much to the amazement

and delight of onlookers and owner alike, not only did the spark plugs come out easily, but also

the cooling fins on the header pipes and bonus: they were able to hand crank the

engine over using the rear wheel! 

 Here Cort, a new Airhead owner, learns to do the valve clearance 

checks on his R75/5 for the first time under the guidance

of Dick Paschen.

 Clem C., recently retired from decades of work at BMW of Denver

made an appearance and provided help as needed.

I must say, this particular RS was quite "clean"

 Matt Parkhouse, on the left, another local airhead guru and former 

Colorado Air Marshall made his normal appearance as well.

 Ed, the gentleman closest to the camera, drove all the way from the

Chicago area, with attending this Tech Day as one of his goals.  He

was visiting his daughter who lives locally, so it was all part of the trip.

Ed suggested I take a look at the rubber diaphragm on Fiona's carburetors

after I described to him the intermittent fuel delivery issues I'd been fighting.

Here's Matt Parkhouse demonstrating how to balance the carburetors

on an Airhead using the shorting plug method.  First time I saw

it, it was like magic, with the end result being a nicely idling and running

set of carburetors!

The crowd, which at one point I estimate was close to 25-30 people and perhaps 15-20 motorcycles, thinned out by around 3:00 PM when I took my leave.

Great gathering, lots of knowledge imparted, I got re-acquainted with Clem whom I've not seen for at least a couple of years (and whom I hope will have time to refurb the carburetors on Fiona soon).  Learned a trick to hopefully make the disconnection of tight fuel lines easier:

Place a suitable washer on the end of the fuel line, you can then

push on it to remove the fuel line without causing compression

of the tube which makes things tighter.

Fiona drew her share of curiosity and questions as well from some of the riders.  It was definitely a friendly crowd around her at times, no BMW purists demanded my excommunication for riding a Russian rig with a Beemer engine in it anyways!