'81 GS550 Cafe Build

[D-Mac]

September 17, 2012

Yesterday I put the rest of the valves back in. Nothing unusual to report here. A few pics….






Since I now have a good shop space at home, I decided to bring the original engine home from my office. Recall that I’m using the bottom end of this engine, along with the covers I polished, but I will be replacing the cylinders/pistons and the rest of the top-end from the lower-mileage parts engine I’ve been rebuilding from scratch.




My next step is to strip down this engine to paint the bottom end. Then I can FINALLY reassemble everything and get it back in the bike!

[Dec79]

Great project dude, I love your work ethic - very neat!

I managed to relocate my ignition on the right hand side just below the tank:



Dec

[D-Mac]

Great project dude, I love your work ethic - very neat!

I managed to relocate my ignition on the right hand side just below the tank:



Dec

I like that MUCH better. It's on my "to do" list at some point. In the long-term, I'm going to do something fun with the gear indicator lights too.

Where did you get your coils? I'm thinking about getting new ones (along with plug wires - mine are pretty ratty).

[ClineDesign]

How did you mount your ignition switch? Really nice work!

[Dec79]

Where did you get your coils? I'm thinking about getting new ones (along with plug wires - mine are pretty ratty).

Dyna 3 Ohms - do a quick search in eBay

How did you mount your ignition switch? Really nice work!

Thanks, a couple of tabs carefully welded to the inside of the frame, took a bit of positioning to get right

[D-Mac]

September 27, 2012

Progress continues and is picking up again……

First off, I got the top end removed from the original engine. It didn’t come apart as easily as the spare that I’m using, but it all looked OK. I might use the camshafts from it, but the rest of the head is probably scrap. Unfortunately, the front bolt where the head meets the cylinders was broken and glued on somehow (?!) As a result, the head had leaked a lot and it might even be a little warped. The fact that the head also has five broken exhaust studs (one reason I’m using my spare), means I probably won’t be using it on another project. At least engines are cheap for these things. Pistons looked ok, but I’ll be using the ones that match the other cylinders.

Anyway, here’s a shot of how it looked during cleaning (don’t worry – I very gently rested the connecting rods on the engine just for this pic – they are wrapped otherwise). Despite cleaning, and cleaning, and cleaning it, it was still hard to keep debris from going into the bottom end. I also cleaned up the threads on the engine studs.





I carefully removed the base gasket residue, cleaned for many more hours with an assortment of pics, brushes, cleaners (mostly a lot of acetone), and rags. Then I spent many more hours carefully taping everything off. I pulled the right cover and oil filter cover and taped the mating surfaces off, but decided to tape carefully over the stator cover rather than removing it.

Then I set up a little painting tent…..


Donned a mask and gloves (I look a little red here!)


And started painting (finally!) Here’s the primer coat done.


At the last minute, I changed my mind and went with “universal aluminum” instead of black. So the only black is the cylinders – just like an old café bike.

Top coat




I also painted the top starter cover, oil filter cover, and outer sprocket cover.

Since my last post, I’ve decided to put a cheap heater in the shop. I really want a fancier one, but this one fits my current budget and works great.


Safety first. So I added some other items ….

Fire extinguisher. I’ve also put a carbon monoxide detector and smoke detector in the shop.


I also have some BIG news about the fuel tank and seat cowling. My wife went to pick up her car from a body shop this week that specializes in European cars. They know her quite well because her BMW has been there FOUR times over the past year (it was hit hard three times while parked and she also hit a deer). Anyway, she noticed that the owner has some nice custom bikes, so she suggested having them shoot some paint for me. They were excited about the idea, so she took the parts to them and a note I wrote with some suggestions. They will fix the dings in the tank, smooth over the original side plates, and shoot some paint within the next 3-4 weeks.

In other news, I ordered K&N air filters and a drive chain this week.

Next up…..engine reassembly and putting it back in the frame! I hope to start that this weekend.

[D-Mac]

Just noticed that the clutch pushrod seal looks shot. Looks like an easy replacement (screw in drywall screws and pull old seal; carefully tap a new one in).

My clutch rod also came right out the left side. I thought it was supposed to be threaded in tight. No matter I guess.....the right-side cover is off anyway and the part it pushes on looks to be accessible enough to hold from that side. Hopefully I can just thread it back in without having to remove the dreaded basket and mess around in there (I didn't look closely, but the parts diagram makes it look like a threaded rod).

What ISN'T wrong with this bike?!

[Sci85]

Nice work on the engine D-mac. And yeah, I feel the same way as do many on here. I'm on my third try with with stinkin gas tank paint job doh!

[D-Mac]

Well, it’s been an interesting couple of weeks, but I do have a little progress to report.

After checking the ring end gaps, I put the new rings back on the pistons, reattached the pistons, and got the cylinders back on.
I had a lot of pics of the process, but I managed to drop my smartphone in a lake last week (!), and the pics were lost.

After the phone fiasco, I was busy finding a home for this….a pig we bought from 4H (mmm bacon!)


….then my old lawn mower blew up. I don’t know why. The oil level was fine, but it came with my house and had over 1800 hours on it, so I suppose it might be due for a rebuild. I picked up a new mower, but there’s more money gone from my “project” fund.


Anyway, here are a few pics of cylinder installation…

The procedure for installing the cylinders calls for placing the middle two pistons up and lowering the cylinders down over them first. I had trouble getting the first two pistons in – even though the cylinders are tapered at the bottom. After trying a couple of times myself (along with a few pieces of wood to hold them in place), I decided to get some cheap ring compressors. Hose clamps would work too, but I figured I might as well buy the tool for the long-term. Here are the middle rings compressed and ready for the cylinders.


After getting the cylinders over pistons #2 and #3, I had a little trouble sliding the cylinders down to meet the outside pistons. It turns out I wasn’t able to hold the crank steady and it was getting turned over. I had the cylinders a little cocked too. With some help from my kids, I was able to keep things steady and compress the rings for pistons 1 and 4 enough to get them in easily. Then it was just a matter of gently tapping down the cylinder the rest of the way, and it was done! New base gasket and o-rings were used of course.




Before re-installing the head, I decided to test my freshly lapped valves. I poured some kerosene into each combustion chamber. After 30 min there were no leaks, but I’ll check again in the morning.


Over the weekend I plan to install the head and begin the long process of getting the valve lash correct. There was no lash clearance anywhere when I began the project, and with re-lapping the valves I’ll have even less now. That, and I also managed to mix up a few buckets. The only way I can get the proper-sized shims is to use thin enough shims so that I can measure SOME gap for each valve, and then place in the appropriate ones based on a known shim used and whatever lash is remaining. Not a quick job methinks.

[Sci85]

Looking good d-Mac! You know the best thing about this time of year? Asking for things you needed for the bike project for Christmas!

[D-Mac]

Two steps forward.......

One set of valves failed the test. Both leaked a little and the chamber was empty after 12 hours.

So I removed and re-lapped those valves a little more. I reinstalled them and the second test was MUCH better. I still had one valve leaking a little more than I wanted, so pulled it yet again, lapped a little more, and tried again. A tiny bit better still (good enough I think - no visible weeping until after ~8 hours, and then only the tiniest amount).

Then, as I was cleaning up, I realized that I'd missed replacing a guide pin between the cylinders and bottom end. It goes around one of the studs, so the "easiest" thing to do was to pull off the cylinders, install the pin, and replace the cylinders again. It was easier the second time, although I still had to get one kid and my wife to help out.

I'm FINALLY ready to get the head back on.

[D-Mac]

As usual, I didn’t manage to get anything done over the weekend. Too many kids birthday parties and such.

As I mentioned the other day, I ended up removing and replacing the cylinders to get the guide pins in, so next up was the head, which was now ready FINALLY and not leaking. The only other thing I did was knock down a fine edge on one part with a jewlers’ file (I’m sure it didn’t matter much, but I didn’t want a fine burr on an outside edge to prevent a proper seal on the head gasket).

It took a little juggling to get the cam chain up through the head without any help. I went with a Suzuki head gasket and o-ring, even though they are fairly pricey. Then I torqued the various fasteners in the designated order in 4 steps. I used all new fasteners because the old ones were a little beat and rusty.

Pretty. Note that I hadn’t tightened some of the fasteners down when I took this photo (like the bolt on the front of the head/cylinder).




Now to tackle valve lash/cam chain tensioner, timing, etc. This will take a while.

[D-Mac]

Big news! Yesterday, I got my seat and tank back from paint. Here are a few pics (things are a little dusty, but you can get an idea; I still need a new gas cap and I have to get the seat upholstery done). I’m very happy with the quality of the work. The shop filled in the various dents and the original side plate attachment points. A few pages back you’ll note that I stripped the tank and re-lined the inside with Caswell tank liner.











My wife surprised me with a professional paint job, but the cost ended up being waaaaay more than I had planned for this bike. Suffice it to say that the paint cost nearly as much as I have in the entire rest of the project budget, so this will be my Christmas present! Before I do another project, I am going to take a couple of courses on painting.

Recall what I started with….. No more “Red Neck Rocket!”




Since my last update, I also started on re-shimming the valves. I started by removing the shims from the buckets of both engines and checking their measurements and markings. The markings are accurate, although they are generally +/- 0.01 in accuracy. Many are marked with an ‘x’ at the end, which seems to indicate that they are considerably thicker than the number marked on them, but still smaller than the next thicker shim size.

My issue is that most (all) were tight and a little mixed up, so I want to start with thin shims, measure the “extra” gap, and then get the right ones in there. Luckily, nearly ALL of the shims on the extra engine are thinner than those from the top-end of the one I’m using, so I swapped each “original shim” with a new one in a way that should give me the greatest gap in each case (assuming I didn’t mix them up too badly when I took the head apart). One was only 0.02mm smaller, but most are now closer to 0.10mm smaller than what was in there before. We’ll see what happens.
Shims, shims, and more shims!



Some of my notes (since entered into a computer so I can track this stuff).



Before I reassemble the cam shafts, I’m going to prepare the cam chain tensioner so that it’s ready to go back on. I now have the replacement parts I need, so I should get to it this week, and then (hopefully) check valve clearances.

[cowboyup3371]

Why not get Steve's Valve Adjustment spreadsheet to make that job a little easier?


Love the look of the tank.

[tkent02]

Sweet paint, that's going to be a beautiful bike.