Running Rich (?) II

[Doughty]

TC, I think it will rev all the way up, no indication that anything bad starts happening as it goes faster.

The original (funky) timing bolts are in there and the timing sits right at the F-mark at idle, if I recall correctly. It moves with the advance solenoid although I haven't looked closely at how much. Probably worth checking... ?

I do have some older pilots - I found a receipt stuffed in the tool kit that suggests the pilots were replaced back in '01 so I doubt the ones I have are the originals. I'll give the old ones a shot though.

Feel pretty good about the octopus - it can dump a lot of fuel on the floor of my garage. I might have something goofed up though. However, I generally run off the reserve setting when I'm tuning to keep the complicated stuff out of the loop.

I have some new NGK BPR6ES plugs in there. New caps as well. They all measure out at 5k.

I have just the two sets of "T"s toward the bottom of the carbs. Bowl venting is an interesting idea. I've noticed that when I first start the bike up it runs pretty well, then after I take the choke off and rev it up a bit it starts running poorly. Have also had the float valves stick open - somewhat inexplicably. I have new needles and seats (no screens anymore). I've given the tank a thorough cleaning (the whole muriatic acid rinse, etc. mentioned elsewhere on this site) and have inline filters so I'm not expecting too much crud to get to the needles. After pulling the carbs a number of times and not finding anything causing them to stick open, I've started blowing a little air into the fuel inlet "T" which seems to free the needle up. Suspicious? I'll have to check the # of holes on the carb inlet bell (it's been a few weeks since I had the carbs off) and I'll do a bit of research on bowl-venting.

AlanB, I'll try the mixture screws. I was going under the ASSumption that if everything was stock, the standard setting would be pretty close to nominal - maybe not?

DennyZ, I went with MikeXS for jets. I got the pilots that it looked like I needed for my particular carbs, however they had fewer holes than what was in there. I'll give the older ones a try.

Jimboreeno, I did do the pick-up wire fix a while back and found that 2 of the 4 wires were broken. I was amazed that the bike would run at all as they were.

Thanks for the ideas, everyone.

[81xsproject]

Really give the idle screws a try. From the advice of TC I run with mine 3.5 turns out and it seems to be the sweet spot.

[TopCatGr58]

Doughty,

You hit a nerve when you mentioned the sticking float! I had one that was sticking a couple of years ago after I had (ineffectively) repaired a broken float post....was slightly crooked causing the float to be on a slight angle and would stick flooding that carb. Throttle response at idle was horrible, it was essentially like an On/OFF switch, was running the twisties in N. Ga. at the time, very interesting riding!

Then, I pulled the carbs, noted the slant, broke and reglued the post on the LEVEL, and it has worked flawlessly since! SO... check the floats, you might need to bend the inwards towards the center a "touch" to keep them from scraping against the bowl sides. I doubt that you have a vent bowl problem, it's a direct line from the inlet bell to the inside of the carb body, and you've blown cleaner thru ALL holes you could find, so it's probably OPEN and breathing okay.

So...it's probably either the float(s) sticking, and or the pilot jets!

Let us know what it is WHEN you get it fixed!!
T.C.

[John]

Originally posted by Doughty
DennyZ, I went with MikeXS for jets. I got the pilots that it looked like I needed for my particular carbs, however they had fewer holes than what was in there. I'll give the older ones a try.

Fewer holes??? That means less air to mix with the fuel in the pilot circuit. That would cause a bunch of headaches.

[LoHo]

Did your new float needles have a little wire keeper to hook to the tang of the float? I rebuilt my carbs and constantly had #3 flood when running. The bike would run, but raw gas would leak out the exhaust. I took those wire keepers off and have had smooth sailing since.

Of course, taking the carbs off, then apart, then together and back on may have solved something else, but it worked for me.

[Hired_Goon]

Ummm, I have three sets of standard carbs and none of them have the wire bit. Is that standard with them all????

Or do I have three sets of basterdised carbs? Or is it only in the rebuild kits?

[skids]

I have never seen them on the 78's (zero out of three) but they were on the 80 and 81s (2 out of 2).

Originally posted by Hired_Goon
Ummm, I have three sets of standard carbs and none of them have the wire bit. Is that standard with them all????

Or do I have three sets of basterdised carbs? Or is it only in the rebuild kits?

[Doughty]

Tore the carbs out today and replaced the new pilots (2-1-2-1 side hole pattern) with the old (no side holes - this is contrary to what I said earlier in the thread).

Checked the bowl vents (there are 2 per carb) and they are clear. I did find a bit of junk in the float valve of #3 that was causing the gas overflow.

I now have idle when it's warm! Progress - but I'm not all the way there yet - it won't run under load.

Started tweaking the idle screws. Opening then up (started at 1.5) made it run worse, so I thought I'd see where the sweet spot was by turning them in. It actually runs the best with the screws all the way in (I backed 'em off a tiny bit so I don't break the pins off.)

Float levels are all about 3mm below the top of the bowl.

With the bike on it's center stand and the mixture screws all the way in, it'll idle a bit rough and, with throttle, rev smoothly up to 2.5K, sputter through to 3k and then rev smoothly on up. As I back out the mixture screws, the rough section gets wider, starting at 2k when I'm 1 - 1.5 turns out.

Off the stands it won't do much. Trying to start out under load it dies almost immediately. Starts roughly but then the idle comes back and it seems okay.

It seems like I'm getting too much fuel into the system at lower RPMs. Could that stall under load be flooding? Seems to happen too fast for fuel-starvation - at least as I imagine fuel starvation would happen.

I guess there are only a couple ways for extra gas to be getting in there. Emulsion tubes/needles or the choke circuit aren't working. Any ideas?

[planedick]

Lean

Have you tried just letting it set and idle for a little while and then look at the plugs. If you have new plugs the mixture will show up immediately. White color = lean, black = rich, brown = just right.

[TopCatGr58]

Hey Doughty,

I hate to say it, but now it sounds like your OLD pilots were the wrong type, probably installed by PO or shop incorrectly. I remember the XJ's pilots not having the holes, but the XS's do use the ones with the holes, that's how the fuel AIR ratio gets mixed. Without holes, it's just sucking in a lot more fuel, and like you said, you've had to turn the pilot screws almost all the way in to SHUT DOWN the flow of fuel cause there's NO AIR being mixed in with them!

You said you found the #3 float valve sticking, which was overflowing=flooding!!! That was most likely the culprit. 1 carb flooding can ruin the low end performance of the rest. I had my #2 carb intermittently sticking due to a poorly fixed float post and angled float pin, caused heck with the low end response, only had WOT and would behave as such cause I was able to access the MAINS that way, but NO PRECISE LOW END Throttle response at all. Fixed the float and all was right in the world again!

So...regrettably you probably need to put the NEW jets in, but NOW that you've fixed the sticking float, it should behave much better! Hang in there!
T.C.

[skids]

What do you mean the carbs each have 2 vents? If yours are truely 80 vintage (did I miss something) then there whould be no vent hoses to the airbox. If your bike has an 80 airbox with the vent nipples filled with plastic, it can cause the levels to overfill with gas. If your carbs are 78/79 vintage, there will be 3 round holes in the inlet bell with one oval -- if your carbs are 80/81 (not all 80's???) then you should have 4 round holes there, one oval, and no vent hose to the airbox.

Originally posted by Doughty

Checked the bowl vents (there are 2 per carb) and they are clear. I did find a bit of junk in the float valve of #3 that was causing the gas overflow.

[planedick]

Just following along..

I am experiencing similar problems except mine is the ilde is too lean and the bike won't excellerate under load until it reaches 3500. I have 137.5 mains, 42.5 idle jets, and 180 idle airjets. I think the problem with transition is because the idle is too lean for the load. I have the top end just right now I have to find a way to get the transition right. Idle is smooth and even, just won't take exceleration under load. Sputters and misses under 3500, but goes on up to redline like it had afterburners on it. Mine is a '78 E.