help!! i am new to the xs1100 problems

[coltglock45]

okay so i am new to the xs1100, i bought the bike on e-bay about a month ago. it is a 1978 xs1100. so i take the bike for a ride and it breaks up pretty bad but if i stay on the throttle it will take off, when it picks up it will give a puff of smoke. i check the plugs and they are burnt but very dry and you can foul them with a 5 mile ride. so i checked online to see some of the problems with these bikes and started to work on it. the one pet cock did leak so i rebuilt them both, then i put on new plug wire 90 degree end boots ( the type you screw into the wire) thats all they had. then i replaced the spark plugs.. this all did seem to help.. but then fouled the plugs again. so i was told it might be the cdi box so i got my hands on one of them and same thing.. now after working on the bike and looking around real hard i find that this bike was dropped pretty good at some point ( i think just b4 i bought it). it apears the old owner replaced the electronic pick up? new cover and newer pick up from what i can see plus i can see someothere things he has replaced since it was dumped.(this is a very clean bike) total shame i can see it was dropped or else it would have looked like it just rolled off the showroom floor. any ideas or thoughts on what might be wrong?

thanks
kurt

[CatatonicBug]

When was the last time you cleaned the carbs? That should have been the FIRST thing you did. Just a tiny bit of build-up can really wreak havoc on the performance. You said that when you open it up, it runs well, but at lower RPMs, it gives you trouble? That really points at the pilot jets in the carbs.

[coltglock45]

the guy b4 me replaced the carbs and cleaned them up so i thought i might not need to. seems like an ignition probelm to me? i did hit it with a little carb cleaner and some seafoam in the tank to see if that would help.. no luck

[TopCatGr58]

Congrats, you've been PO'd!

Hey there Colt,

Big red flag just went up when you said the P.O. replaced the carbs. There are two style of carbs for these machines, the 78-79 series, and the 80-81 series. You/we need to first determine if any mix matching was done.

The 78-79's have a bowl vent tube on the upper body of the carbs, and go into "T's like fuel, but then into the airbox IF it still has the OEM box.

The 80-81 carbs have the bowl vent built into the inlet bell of the carb, so there are 4 small ports/holes instead of just 3 holes along with the larger arced vacuum slide port at the top.

ALso, the 78-79's have the PILOT adjusting screws as EXTERNAL on the top front of the carbs, you can see the screw head and spring, the 80-81's have the screw down in a tunnel in the same location on the carb body.

Also, the early carbs use a screw to cap off the pilot JET from the float bowl, it's fed thru a sharing tunnel from the MAIN JET, and there can be many problems, from using the wrong type of pilot jet, to not putting the pilot jet tower cap in place, etc.!!

SO....verifying the year/model of carbs, and then a look inside will go a long way in diagnosing your plug fouling problem.
T.C.

[coltglock45]

thanks a ton t/c i did not no that and did not think of that one bit! i will check it out first thing in the am and get back to you.. hmmm i do know he picked up them carbs from e-bay.. good news is i do have the old carbs too. sounds like a great start!!

[DGXSER]

check the gap on the pickup coils as well. If that area took a good enough hit to bust the cover as I think you stated, it could have jarred things in there and messed up the gaps. JAT

[trbig]

What you describe sounds fuel related to me. Sounds like your float valves are letting fuel by them and loading up. It would be fine when on the throttle, but it would still flow when off, loading up the cylinders and fouling your plugs.

And along with the others here, I shudder at the thought of a previous owner doing something and trusting them. Sounds like a good carb clean and a bench check on the floats would be in your future... in my opinion.


Tod

[aussixs11G]

NEVER trust the PO

check it all out for yourself is the only advice I have.....

[CatatonicBug]

check it all out for yourself is the only advice I have.....

I second that emotion!

[coltglock45]

ok, so i check the carbs and they are ok. (as far as the year) but what i did find is that the cover on the left hand side that is for the advance was loose and i could take the bolts out buy hand... now i can so the p.o replaced this cover and the advance do to it being dropped... now i suspect the timing is off. fact is im sure it is off. any help ? i am not too sure what proper steps i should take with putting this thing back in time correct.. i am very sure this is the problem. and also im not too sure about that pick-up being ok? do to i think some water may have got in there do to the cover was very loose. any helpful hints would be great!! thanks for all your feed back so far..

thanks
kurt

[DGXSER]

If ti were me, I'd start by checking the gap on the pick up coils, then check for signal at the TCI from the pick up coils.

If all that checks out, then set the timing. I'd rotate the engine with the valve cover off and a sick or straw int he spark plug hole of no 1 cylinder. rotate engine by hand and watch for the intake valve on no 1 to open and as it closes watch the stick for it to rise up. when it stops rising, note where the timing marks are on the plate. Should be close to the T mark. Watch the stick as you continue to rotate and there should be a dead spot where it does not rise or drop. When it starts to drop again, look at the timing marks. T mark should be halfway between those two points.

Now that you have the timing sorted pretty close, use a timing light and start the bike. Set it per the manual. Mine being an 81 I have no timing adjustment from the factory so I do not recall the settings.

[DiverRay]

BEFORE you start in on what dgxser said, look at catatonicbug's reply and click on the link in his signature. This will hook you up with an electronic copy of the manual that is Needed to work on the bikes!
On the '78, with modern fuel, you will need a float level of about 1.2" above the gasket surface (carb body) in order for proper running.( this DOES sound like a bad Japanese translation, correct???) I would also look at the needle seat assembly to see if they are worn. The only other thing I can think of is the coils are going bad. That will be something to think about if the carbs don't get it runnig properly. Carbs ARE about 75% of the problems with these old bikes, and 90% of that is P.O. problems!!
If you put your location on the signiture, you may find another owner somewhat close by willing to help for just a little liquid refreshment!
Welcome to the container of knowledge!!!