Fired up for the first time, how to keep it running?

[oakback]

1980 XS1100 G

So far I've cleaned out the tank, cleaned out the carbs, cleaned out the petcocks, installed new fuel lines (with filters) and vacuum lines, cleaned out air box (removed remaining bits of foam and wrapped the filter screen with pantyhose). I verified spark at each spark plug.

I got it to fire up for the first time today.

It will only run with the choke on, and with some throttle. It blows rich exhaust, some black smoke. Where do I go from here?


More background info: the guy I bought it from bought it from a mechanic. A customer dropped it off to get carbs cleaned, then the customer went to jail (supposedly). When I cleaned the carbs they looked like they had been cleaned, very little varnish in the bowls. The diaphragms looked brand new. One of the petcocks looked like it had new rubber in it. Either mechanic or myself (I'm not sure) mangled 2 of the main jets, I replaced them with 2 new jets. All jets were cleaned and blown out with compressed air, I tried to be absolutely thoroughly. I didn't adjust or remove any of the air jets.

This bike has all kinds of other problems that will need fixing (brakes, lights, tires, seat, tank all beat up, etc.), but I want to be sure I can get it running well before I even bother sinking money into other parts.

[Donmystic1]

Look for the Youtube video on disassembly of the Mikuni carb.
You need to take out and clean the pilot jets and emulsion tubes to start.
Then the needle valves etc.

[oakback]

Yep, did all that already. The only thing I didn't remove were the air jets, because at the time I was hesitant about messing up mixtures or whatever. I cleaned them out, just didn't remove them. Everything else that I could remove, I did, and cleaned thoroughly with toothbrush and B-12, also used thin wire where possible, and compressed air. No debris or varnish or anything was left anywhere.

[mrhammer2u]

bumping this thread b/c I'm interested in the fix

[motoman]

Yep, did all that already. The only thing I didn't remove were the air jets, because at the time I was hesitant about messing up mixtures or whatever. I cleaned them out, just didn't remove them. Everything else that I could remove, I did, and cleaned thoroughly with toothbrush and B-12, also used thin wire where possible, and compressed air. No debris or varnish or anything was left anywhere.

Pilot circuit likely still the culprit havin' to use enricher to keep it running.
Would look more closely(magnifying glass) inside those pilot jets. That internal chamber of them traps 'science projects'. Teeny atomizing hole in end may need a closer look-see. Its too small to poke anything thru(keep metal wire,etc. away from ALL the jet orfices....toothpic is best for all the other sideholes of pilot jets and emulsion tubes, and cleans shoulders of those holes well. Compressed air blown thru that atominzing hole of pilots from the end, not screwdriver slot side, with good eye and magnifying glass would fonfirm their open.

[DiverRay]

Pull carbs, and mount on a vise or something same angle as on the bike. Hook up a fuel can above the carbs, and see if they leak. give it 2 minutes, as I think the problem may be the "O" rings that seal the seats for the fuel shut off needle. Also, VERIFY that ALL the floats are the same. These are the two main reasons for carb problems on the "new" style carbs. JMHO

[oakback]

Thanks for the tips. I'll try those things and report back.

Regarding videos, I watched a few others and apparently the one I used left out a few steps, I'm sure I'll get it this time.

[motoman]

Thanks for the tips. I'll try those things and report back.

Regarding videos, I watched a few others and apparently the one I used left out a few steps, I'm sure I'll get it this time.

............non of which impress me..........you'll get better info/ help here.....and more specific.

[Bikes]

Ck the ignition pick up wires......i know its not carb stuff but pretty common fail and could certainly cause mis fires, smoking, etc...
Two of mine were broken.....made a world of difference...

[oakback]

Ck the ignition pick up wires......i know its not carb stuff but pretty common fail and could certainly cause mis fires, smoking, etc...
Two of mine were broken.....made a world of difference...

If the plugs are getting good spark by looking at them, could that still be the issue?

[bikerphil]

Bad P/U coil wires could cause an intermittent spark when the engine is running due to them flexing with timing plate movement.

Edit:

My bet is that your carbs pilot circuit is still plugged, you really need to disassemble them further and blow out the carb passages with carb cleaner/air.

[oakback]

Understood, that'll be my next step for sure.

[natemoen]

Here is the walk through on cleaning the carbs.

http://www.xs11.com/forum/showthread.php?t=36017

[oakback]

Pilot jets were nasty. Got them spic and span, could see nice round daylight through all the holes. Now it'll run without the choke (and with less smoke), but it still runs just as rough.

Here's a short video, does it sound like it's running on all 4 cylinders?

video

[oakback]

To add, it won't rev up at all. 1/3 to full throttle, makes no difference. It cuts out on its own, as it did in the video.