new carb holders, and it now runs rough

(my first post in this new site!)
Hi everyone,
I just installed a set of new carburetor holders (intake manifolds) to my 83 1100 Ltd. The motor runs rough now. It idles ok, but it's lacking power when actually ridden, even at very slow speed. I also hear strange sound. It sounds similar to running with only 3 cylinders firing.

The bike was running fine before the carb holder installation. However, I knew air was leaking from the old holders. My question. Is it possible that these new carb holders threw the fuel system out of balance? The carburetor was synchronized about 3 years ago. Do I need another carb synchronization to adjust the carbs to the new air-tight intake?

Things I checked:
- air leaks from new carb holders
- vacuum hoses
- fuel flow
- sparks

Thanks in advance.

Nob

Post edited by: nob_1100, at: 2006/08/29 22:15

im no carbonater expert but i would think if the carbs were tuned to compensate for leaking carb boots before,they might be running rich now.:whistle:

Thanks for your reply. I didn't check spark plugs to see if the gas was too rich/lean, but it makes sense. I'll see if a cab synchronization will fix it. (I hate that mercury stuff:pinch: )

Did you use any sealer between the boots and head?

In the first try, without any sealer, there was an air leak. I put a high-temp sealer on the mating surfacses and it fixed the air leak.

In case someone encounters the same problem in the future and come here to search solutions...

The new carb holders indeed threw the carburetors out of synch. I synchronized the carbs and the engine runs very smooth now.

But the day was filled with bad karma. The battery ran out of juice TWICE, so I had to interrupt the job to recharge it. Also, my petcock decided to start leaking during the synchronization job.:pinch: I happened to have a rebuild kit, so it saved me. When I synched carbs before, I used one of these mercury type manometers. I didn't want to poison myself with mercury again (I know I did before:woohoo:), so I made and used the "yardstick" manometer. Mine was actually a broomstick manometer. The carbs were so out of synch that the engine kept sucking in the ATF fluid I put in the monometer tube. Towards the end of synching job, the engine was running really rough...it sucked in too much ATF oil I suppose. I decided to ignore the terrible sound from the engine and concentrated on the manometer reading. After finish synching carbs, I checked spark plugs. They were incredibly wet as you guessed. I put them back in after thoroughly cleaning them...and voila! the engine ran as smooth as butter. I was so happy and decided to take a spin around the neighborhood. Very smooth and no vibration. I was approaching my house, feeling a sense of accomplishment... then it happened. I heard strange cyclical sounds coming from the rear end. I couldn't believe my luck. I got a flat tire caused by a door key that stubbed the rear tire.:pinch: In my 20 years of riding motorcycles and cars, I've never, never got flat tires from a door key. Why today? Ive got an even better ending of the day. I entered home, feeling defeated, and decided to take a shower to wash away dusts, sweat, ATF fluids...only to find out that no hot water was coming out. The water heater decided to quit. At this point, I would simply say, WHATEVER!!!

nob

Post edited by: nob_1100, at: 2006/08/30 22:33

There are two types of carb holders (intake manifolds) that will allow a 34mm carb to fit. The difference is how they are molded as the outside of the venturi that goes into the carb holder is shaped differently on different types of carbs. If you use the wrong intake manifolds, you can get a bad seal... not saying this is the case here, just tossing this little tidbit out.

Nob, sorry about your bad day. I guess we all get them from time to time.

Your story of the flat reminded me of the time when I was a poor college student. I just got a new set of rear tires on my car and I was driving somewhere and got a flat.

Turns out my tail pipe had rusted off the muffler and was hanging down and dragging on the inside sidewall of my new tire. It completely wore through in about 15 miles. Luckily I had a spare, but the new tire was shot.

wiredgeorge, I'm pretty positive that I've got correct carb holders. They look similar to the old ones. But thanks, I'll watch out in the future.

Thanks IowaKZ, your story is therapeutic to my sunken spirit! It's a story that you can laugh about now I guess. All these bad things that happened to my bikes in the past are good memories.

I'll fix the flat tire tonight but I'm anticipating to encounter another trouble as soon as I finish fixing it!

Nob