Mad Dog’s Own “Buyer Beware” Panhead Saga

Story & photos by Mad Dog

Another bro’ with a story about his pan!  Our bro, Mad Dog, from down in the Virgin Islands, has a righteous panhead in his own right. -MetalMan

My Pop had alerted me to the ad in the classifieds, went over to check it out and told me that it looked like it was in pretty  good shape. I called the owner and got some info on the bike. The scoot had only five miles on her since she was reassembled and he couldn't tell me all that much about what had been done during the re-build. This should have been the first clue to chime me in to the damnation that was about to occur. The guy had all the receipts for everything that had been done and it seemed pretty thorough. He'd used a local shop to do the rebuilding and it was supposedly stroked and bored, but again he couldn't give me numbers and had no idea what cam grind was in the bike. After we had negotiated a price, Pops picked it up for me.

Pops and I were planning on attending Daytona together, so this was the first time I got to see her. For the most part she ran well and I only had to fix some minor problems that you usually have to tend to during a typical shakedown run. After bike week was over I boxed her up and shipped her to my home in St. Thomas.

Once she was home I got her registered as soon as I could, then headed over to a rally in St. Croix. Of course I ran into trouble when I wasn't able to conveniently get to my box of wrenches. The first problem was when the clutch hub nut decided to conveniently back off  in the late evening when there was no way of getting into any shop. This screwed up my first night of riding. The next day I limped it to a garage where a bro was kind enough to let me use his tools and an impact wrench. I got the damn thing back together and managed an afternoon of excellent riding.

“Shit happens” #2 occurred in the evening when the front cylinder cracked. This really left me up shit creek without a paddle. I mean, J.B. Weld is a fine product and I've used it in many creative ways, but this time it just wouldn't cut it. Screwed again for the rest of the weekend, I was forced to resort to renting a cage to get to the rally sites.

Back home in the garage I took her apart. Lo and behold, I discovered that the bike indeed was stroked and had an S&S 4.625" inch flywheel and rods. And the cylinders were bored, too, a whopping .070" over on a set of stock barrels. The excitement subsided a bit when I discovered the pistons were for a shorter stroke motor. The squish was all right, but the pistons were never clearanced properly and they had scuffed the flywheel. No damn wonder the cylinder cracked!

I do all my own work and I'll be the first to admit that I'm no expert wrench. A lot of what I do I have to do myself because there just isn't a bike shop in the Islands. I learn as I go and usually have to ask a lot of questions from folks in the states. Fortunately I'm pretty computer literate and I got a lot of help from knowlegeable people on newsgroups like rec.motorcycles.harley and from e-mailing S&S direct at sstech@sscycle.com. S&S was especially helpful and I was able to get what questions I had answered through them.

Once I ordered the correct set of pistons I also ordered a replacement set of barrels. Though I lost a few inches in engine size, I gained a lot of piece of mind in the reliabilty arena. I took the new pistons and barrels and had them machined to S&S specs. I could have done this myself, but I figured this was better left to a professional who does this kind of work everyday and has the equipment to do a proper job. The drill press and honing tool from Western Auto probably isn't the best idea.

While the barrels and pistons were at the machine shop, I thoroughly cleaned the heads. They are aftermarket aluminum jobbies with a pan bolt pattern and shovel ports. I found a high temperature paint that matched the color of my bike and hit them with this. After the paint cured I sanded the edges of the fins and buffed them out to brilliant shine. It's amazing how aluminum buffs out with a bit of polishing compound. I even prefer aluminum over chrome because of the corrosion factor in the Virgin Islands. Once chrome gets any rust on it, it can't be salvaged. Aluminum on the other hand can be returned to a brilliant luster.

I also used the downtime to pull the cam cover off and polish this as well.  It had been painted black, so after a bath in paint stripper it was back to its dull aluminum finish. Some fine sandpaper and steel wool worked out all the nicks and scratches. I then buffed it with polishing compound. While the cover was off I also took the opportunity to remove the cam and check things over. I also pulled the screen on the oil pump and made sure than no metal parts from my mishap ended up in the oil system.

A couple of days later I had the barrels back and treated them to the same colorful chemical bath. I gapped the rings, again, according to S&S specs, coated them in oil, and slipped them on the pistons. Then I slipped the pistons in the barrels after a good coating of oil to both. I used stock sized pistons so it didn't matter what direction they faced. A larger bore may have the piston skirts cut at an angle so they don't hit one another at the bottom of the stroke. I had checked the piston clearance to the flywheel before I sent everything to the machine shop, so this didn't need to be done. After installing a new base gasket I then installed the pistons on the connecting rods while they were in the barrels. This can be a bit tricky and helps if you've got a buddy who can hold the barrel while you slip the wrist pin through the piston. Other wrenches prefer to install the pistons, then the barrels, but I think this method is much easier and a lot less frustrating. I kept a rag stuffed snuggly around each connecting rod. Losing a wrist pin clip or plug into the case is not a pleasant experience when you're this close to having it completed.

With the barrels on I torqued the base nuts to spec. Then I got a couple of new head gaskets and slid them on the heads. I lubed up the domes of the pistons and the inside of the head, then placed a piece of "Silly Putty" on the piston and bolted on the head. I did he same to the opposite cylinder and spun the engine over twenty times. I took the heads off carefully and measured the thickness of the putty. It was well within range and no clearance problems were noted, so I cleaned everything up and bolted on the heads for good.  One thing to keep in mind before a tear-down is to remember which head bolts went where. Some of mine were shorter than others and finding what ones would fit took a couple of tries. Once they were on I torqued them down to 65 ft. lbs. A nice device to have for this procedure is an H-D head wrench. Not much else fits.

Installing the pushrods was easy because they are adjustable and I have solid lifters. Getting an exact adjustment can be tricky, but you don't have to sit and wait while a hydraulic unit bleeds out. I adjusted each one so that that they moved freely, but with some resistance. I compare it to the same resistance a brand new sealed bearing may have when you spin it. I used the kicker to turn the engine and adjusted one pushrod when the opposite one of the same pair was fully extended pushing the valve open. Having a wooden clothespin to keep the pushrod cover up while you're adjusting is a must to keep from getting aggravated. (A rubber band with a couple paperclips bent into hooks making a mini bungee cord work, too. -MetalMan)

The engine was now together and just needed the carburetor and pipes installed. After fooling with these items the tanks went on, in went some fuel, and she was ready to be brought to life.

So my sight unseen purchase may not have been such a good deal after all. For me it was a lesson in shopping. I have no buyer's remorse. If anything I learned exactly what was in my engine and have the faith that the top end is now in order. Worries about how the bottom end was assembled still wakes me up at night in a cold sweat every once in a while, but after 30 hours on the engine and no problems most nights are spent just sawing logs.

Back, I say, BACK!                

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