Saturday, April 26, 2008

The bike is together...

Just a quick post. I've taken my motorcycle apart, installed new gaskets (cylinder base, head, and valve cover), reassembled the engine/motorcycle, and the bike starts. I'll take a test ride tomorrow. Wish me luck.

Sunday, April 20, 2008

Rats and being wrong

First, I had rats. More specifically, my house had rats living in the attic. We've taken care of the "construction errors" that allowed entry into the home, and the rats in the house have all been trapped, thanks to the help of an exterminator. I decided to clean up the nests myself. It wasn't a difficult job, but I do not recommend it to someone who is not familiar with how to use a respirator. You probably won't catch anything from cleaning up rat droppings, but you could catch HPV (Hantvirus Pulminary Syndrome), which has been reported in Southern California recently and can be fatal. The virus is transmitted by breathing dust left from rat droppings, urine, and saliva. Make sure you really know how to use that respirator, and it probably out to be a full-face model with a HEPA filter.

I removed four large and one small nest from my attic. I used a hand vacuum to remove all the droppings, and I disposed of the vacuum when I was finished. (I don't believe I'd be comfortable using that vacuum for anything else.) I sterilized the place the best way possible, with lots and lots of Lysol. That stuff kills just about anything, it's cheap, and if you use enough of it, it will get everywhere. I used three full cans in my attic.

And...my motorcycle is still not running. There was no oil leak from the tachometer cable, and everything else looks good. The oil is coming from a cylinder base seal that I did not install properly. There must have been some oil on the mating surfaces that prevented a seal from forming. I've ordered the parts I will need to replace in order to fix this (new head and cylinder gaskets), and I expect to receive the parts on Tuesday. At least I know exactly how to repair this. Let's hope that I'll be riding to work by the end of the week.

Sunday, April 13, 2008

The bike is still not finished.

Last weekend when I rode my motorcycle, it was dripping oil when I finished the ride. There was oil dripping off the engine, from the top to the bottom. I suspected that the problem was a leak in my head cover (aka valve cover) gasket, so I re assembled the cover using high temp silicone RTV to help seal the gasket in place. Today, I washed the bike of all the old oil, and took the bike for a test ride, and it looks like that took care of the head gasket leak. But there is still oil on my engine that should not be there.

I had taken the bike for a 15 minute test ride; riding at speeds of about 15 mph in my neighborhood up to 60 mph on the county highway that runs through town. This oil leak was covering the front of the engine between the exhaust header pipes, and there was a lot of it. At this point I was thinking (and saying under my breath, I do have children) many things that would make this blog unsuitable for audiences of all ages. After dinner, I looked at the bike again, checked my Clymer repair manual, and still couldn't figure out where the leak was coming from. It was only on the bottom of the engine, and I had a hard time believing that the new cylinder base gasket that I had installed was the source of the leak. At least, I was really hoping that the leak was not the base gasket. Fixing that would require a complete disassembly of the engine, again.

I checked out my bike's online community, www.gstwin.com, and found a little gem. One of the posts in the forum mentioned that sometimes the tachometer cable can be a source of an oil leak. The tachometer drive cable attaches to the engine directly above where I was finding oil. I checked my cable, and it was oily. I had packed a small amount of grease into the end of the drive cable, and it had all been washed out. Bingo! I'm going to talk to the parts guy at my Suzuki dealership and see if he has any ideas about this. I may need to replace the cable ($11), or there could be a seal in the tachometer drive gear that could need to be replaced. I'm hoping this is my problem. But until then, hang it all, I'm riding and checking my oil frequently. I'm sick of being stuck in my cage!

Sunday, April 6, 2008

Together, but not finished...

I put my bike together today. Everything went together relatively smoothly. (I've always had a difficult time installing the air box--there's not a lot of wiggle room to get that part back in.) I turned my fuel selector to 'prime' for a bit (to fill the carburetor bowls), back to 'on,' and started the bike up; it sputtered a bit, caught and quit. I switched the fuel selector over to 'reserve,' and the engine caught and ran just like it did before! Success! I had to run the bike on reserve because I only had a small amount (~1 gal) of fuel in the gas tank when I took the bike apart. There was a bit of burning grease from the assembly process, but nothing unexpected. I let the engine warm up, adjusted the throttle cable, clutch, and idle speed (all things that were changed or replaced during the rebuild). I then changed the oil to get rid of anything I inadvertently got in there, like grime, cleaning solvent, or 5W oil from my oil can.

Since everything seemed to be going so well, I took the bike for a short spin around my neighborhood. I cruised around going 15-20 mph for 5-10 min, then I decided to take the bike out to the main road and took the bike up to 35 mph for about 1/2 mile. Another minute or two and I was back in my driveway. Everything went well. I readjusted the idle speed, and saw oil dripping from my engine. Working my way up from the bottom of the bike, I found oil on my cylinder base gasket, then on my head gasket, then on the tachometer cable, then on the spark plug gasket, then on the head nuts, then on the head cover gasket. My head cover gasket is leaking, and in retrospect, I'm not surprised. The new gasket is a soft rubber thing that was stuffed into a bag before I put it on my bike. It didn't hold it's shape well, and kept springing out of place when I tried to install it. I'll get some high temperature silicone sealer, and take care of it soon. I'm getting tired of being stuck in my cage every commute!

Here's a quick look at my newly assembled, but not washed, wheels. My 1999 Suzuki GS500EX. I love this bike.


Saturday, April 5, 2008

Bike Reassembly

Today, I put my motorcycle back together, mostly. I cleaned the crankcase, cylinder block, and head as best I could with solvent, and I carefully put everything back together with the new gaskets. The gaskets appear to be made of stamped aluminum with some sort of coating. I'm hoping I got everything together well enough. All the head nuts are torqued down, and I won't know if there is a leak until I fire up the engine and/or do a compression check. Both of these checks require the engine to be running, and I'm not quite there yet.













It looks like I put the cam shafts on in the correct orientation; I checked the alignment

at least five times before tightening everything down. After I got everything tightened, I manually turned the engine over several times by rotating the crankshaft with a wrench. Nothing seemed to be seizing up, and I felt what I believe to be normal compression. At this point, I believe I was able to reinsert the pistons into the cylinders without damaging them. Again, a compression check will tell me what I need to know.

Since I've now got my engine back together, I've turned my attention to the carburetor. It was the right carb that seemed to be giving me trouble, so I disassembled it first. I didn't find any clogged jets or ports anywhere in the system. The only abnormality I did find
was the carburetor piston seemed to be slightly stuck when I removed it from the body. The piston is attached to a diaphragm, and pressure differences on either side of the diaphragm raise or lower the piston, which in turn raises or lowers a needle valve that controls fuel flow within the carb. Maybe my problem was as simple as a stuck piston that can be fixed by a simple disassembly and reassembly. I'm certainly hoping that is the case. (There's a quick connect in the parts picture. I'm toying with the idea of putting those between my fuel tank and petcock to make tank removal easier.)

Tomorrow I will be replacing a few fuel lines. (I wanted to complete my carb work before deciding how much tubing to buy.) After that, I've only got a few parts to reattach to the motorcycle: carburetor, air box, fuel tank. Then I've got to run the fuel/vacuum lines and reconnect the control cables.

After all that, we'll see if the bike is running again, and if I was able to correctly diagnose and fix my mechanical problems. Wish me luck.

Tuesday, April 1, 2008

A little oil leak.

About a week ago, I noticed that my motorcycle had an oil leak between the cooling fins on the engine block. I cleaned off the oil, rode the bike, and saw new oil in the same place. A few days later, my pants leg had a fine spray of oil on it. I examined the bike and realized that the oil was coming from a leaking head gasket. Hey, it's a $20 part; how hard can it be to fix?


I pulled the seat and frame covers off, and I removed the fuel tank. This I've done before, and it went smoothly. Then I had to pull the air box and carburetor out. I drained the fuel from the carb float bowls, and nothing came out of my right carburetor. So now I have to disassemble and clean my carbs. I just set them aside in a plastic bag to keep them clean.






Next I removed the head cover to gain access to the cam shafts. I rotated the crankshaft with a 19 mm wrench to line up the markings on the crankshaft with the pickups. This lined up the camshafts so that I could position them correctly when I reinstalled them.









Now, with everything off the top of my engine, it was time to remove the cylinder head so that I could replace the head gasket. Btw- Every gasket I've pulled off the bike so far has needed to be replaced. All of the gaskets were tearing or brittle. In fact, I only got a few off of their respective seals without destroying them. The rest stuck and tore. A this point in the repair, I've racked up around $90 worth of gaskets that need to be replaced as a result of my teardown.

I tried to remove the cylinder head from the engine, but it just wasn't budging. I gave the engine block a few taps with a 16 oz. rubber mallet, and then pulled on the head again. I lifted the head up, bringing the entire engine block with it! The oil that had leaked out had carbonized and glued my cylinder head to the block, allowing me to lift the entire engine block off the engine's lower end. I now had yet another gasket to replace (the cylinder gasket). I started with an oil leak, now I'm doing an engine rebuild. C'est la vie.

So now I have my bike apart with the engine block on my workbench, and the pistons sticking out of the lower end of the engine that's still in the bike. The good news is the pistons and cylinder walls look to be in great condition, and the gaskets I ordered on Monday morning are all here today. I've got to clean all the parts I've removed so that the new gaskets seat well, and I've got some carburetor maintenance to do, too. I've decided to replace the clutch cable while I'm in there (it was in the way; I removed it to get the engine block out), and we'll see what else happens while I've got the bike opened up. How hard can it be to replace a simple $20 part, anyway?

I had to remove the exhaust to get the head off.

Here's the culprit.

My engine on my workbench. You can see the burned oil on the cooling fin of the cylinder block (block on the right) on the upper left corner.

Two pistons with nothing to do.