Torn Carb Diaphragm and Stripped Jet

When I pulled and cleaned the carbs, I noticed a ripped carb diaphragm. It is probably one of the reasons that the bike would not run under load. The diaphragms work under a vacuum and when the bike is sitting still the engine requires very little movement of the diaphragms to pull the carb needles up when you rev the engine. But under load (riding) the diaphragms actually move quite a bit. a torn diaphragm equals no vacuum and as such no movement of the needle, resulting in a poor running bike. That coupled with the dirty carbs and I hope I have solved the problem.

I fixed the diaphragm today using Permatex RTV Ultrablack High Temp gasket seal and hope that it is good to go tomorrow (24 hours to cure). I can remove the top side of the carb while it is still on the bike, so I can check it as needed.

The jet however is underneath the carbs and I will need to remove the bank of carbs one more time to remove and replace it. I am going to try to see if I can run it without replacing the jet for now, and wait until I have a little more cash.

I hope to be up and running this weekend. If not, I will break down and replace the jet.

In the meantime, I have almost completed the 3D Maya model of my virtual 1980 XS1100 Special as chopped in the real world. I think that it is coming along well. Much like my real XS11, this virtual XS still needs some engine work.

Totally Rebuilt Carbs

Thanks to a wonderful and understanding wife who took over the care our sick kids, I was able to spend the entire day in the garage this Saturday. Now I have a clean garage as well as a very clean set of the carbs. It took a lot longer than I would have imagined, but I think I got all the gunk cleared out. It took a set of tiny brushes, two cans of carb cleaner, time and a set of steel string guitar wires to clean out a myriad of tiny ports and holes, but after a good soak, scrub and cleaning, all four carbs are back together. As soon as the new Petcock kit arrives, I will rebuild them, install the tank, sync the carbs and zing off into the sunset... or maybe just cruise around town a bit.

Plus, now I have a sparkling clean garage to play in.

Still roars but no Varoom

Well, it seems that the carbs on these bikes are touchier than I thought. I cleaned them out so that they looked clean, but apparently the insides of the channels need some thorough going through. I will need to re-clean them using welding tip cleaners and such.

The bike starts and runs fine in neutral, but in gear it will not rev. Rather, it sputters and dies. And so I will need to remove, disassemble and clean the carbs more thoroughly before I can ride the bike.

Also need to rebuild the fuel petcocks because one has sprung a leak. I am no expert, but fuel leaking into a hot engine or exhaust doesn't seem like a really bright idea to me.

In the mean time, since I cannot ride the bike, I am developing a 3D version of the XS1100 in Autodesk Maya.

Roar!!!!

And so, with the carbs cleaned, I filled the tank and prepared to coax the bike to life. By coax, I mean the usual riggormaroll: throttle up and down, choke it in and out, bounce on the seat, let it sit, try again in ten minutes... etc.

BUT MY FRIEND.... THIS WAS NOT TO BE ON THIS FATEFUL DAY.

I turned the key to the on position, started the fuel flowing and hit start... BOOM! CHUGGA ROOM! VROOOM! It roared to life with a sound that makes even large bikes whimper!

IT IS ALIVE! Mua Ha Ha!

But seriously, it literally roared to life! varooom. Apparently, I had the throttle set too high from when the carbs were dirty, so it quickly jumped into the 7000 RPM range. After a little tweaking I have it humming nicely at 1500 RPM. I still need to hide the wiring mess in the front fork bag, but that is a ten minute job for this evening.

Man it feels good to have it purr like that. I feel ready to take on the world. But I have to teach class in a few minutes, so I will hope back into the JEEP and drive, not ride to work.

Will post pictures of the painted seat this weekend.

Man, do I feel good. I really built a bike! I mean really... and it works afterwards! Better than when I bought it! Ha. Thanks again to all of you guys for all of your support. I am on cloud nine!