Carbs? Or what

[Tazcop]

Hey guys I am the proud owner of a 1978 XS1100 it is a nice bike which I'd like to ride instead of looking at sitting in my garage.
I had problems with the carbs (Who hasn't yet?) cleaned and replaced pilot screws and carb slides. The bike start good and idles until I run it for about 5 minutes then it will die unless I keep reving it up. Also it sputters and runs like crap it doesn't have the power it should. I reach 60mps and the throttle is almost fully openand no power. It seems like the bike is starving for fuel (maybe) and I get real crappy gas mileage.
Please any suggestions at where I should be looking next to fix this problem. Is there a fuel filter and where? (my mechanical knowlegde is about zilch, null, zero)
Thanks in advance for any help.

Taz

[Geezer]

The carbs are a good guess. Read the thread on carb cleaning, it's full of good stuff.

BTW, do you have a standard or a Special?

Geezer

[Geezer]

Duh, never mine 78=standard.

Geezer

[Tazcop]

Thanks Geezer for the advice on the carbs I'll keep looking up what I can and keep working on it.

[Jeff]

My question would be why you needed to replace the mixture screws and carb slides?

As Geezer stated... there is a wealth of info on this site concerning carb cleaning..... and the infamous "triple cleaning".
It would be very difficult to be TOO thorough in cleaning the XS carbs.

I would be led to think that the pilot circuit is overly rich for some reason.... such would be similar to leaving the idle enrichment circuit or choke on. You didn't by any chance have broken mixture screw tips? Have you checked the plugs.... and are they fluffy black coated?

[dragxs11]

How long have you had this bike? When did this problem start? What, if any mods and aftermarket parts are on it? How many turns out are your pilot screws? Stock needles and jets?
You've described a very rich condition at idle, at least in the pilot circuit. If the pilot jets have been changed, you could be in trouble. The pilots that come in the rebuild kits from Yamaha are way to big(I know from recent experience). It sounds to me like while your at it, you might as well check the float levels, check the airbox for free air flow, and if you can, make sure the muffler(s) aren't clogged. And I agree, you can't clean them too much. The carb concept is pretty simple, but the parts are precision.
Matt

[Tazcop]

Thanks all for the tips .

I changed 2 of the pilot screws because the tips were broke. A friend of mine got them out. The spark plugs are, as you said it, coated black and that same friend of mine who used to be a motorcycle mechanic adjusted the floats.
I had this bike for 2 months and it only has 16000 miles on it The guy I got it from said it has been sitting for quite some times. I was told if this bike sit for a long period of time I will have a lot of problems with it.
Like I said it is a nice looking bike and every one who knows about the XS1100 told me it would run out about anything out there. But right now grandma in her Yugo passes me like I am standing up on jacks
Thanks again for all you guys reply I am sure glad I found this site it has been a lot of help.

[dragxs11]

It's going to take some time and patience to get it happy again. If no one has really dismantled the carbs and really cleaned them out, that needs to be done. Also, read EVERYTHING you can find, and talk to anyone you know to learn more about these bikes. Your right, this site is a weath of information. It sounds like you may need to become somewhat of an expert on how the carbs on these things work, as many of us have. I don't know too much about the vaccum lines on the older ones, you may want to look into that more. For whatever reason, the pilot circuits aren't getting enough air, or too much fuel. We gotta get it to idle first, then sync the carbs, then worry about the top end power.

[Dennyz]

Don't use K&L carb kits!

[Snow]

Word - es verdad - true dat:
Definately don't use K&L carb parts unless you are a masochist. I'm hoping my new carb kits will be in soon.