Still have problems after carb removal/rebuild

[ejoy1220]

I was having gas pour out of the #3 carb into the airbox and was having a problem getting the bike to run correctly.

http://www.xs11.com/forum/showthread...threadid=17835

Removed the carbs, cleaned them thoroughly, rejetted them for 4:2 exhaust and Mike's XS pod filters (142.5, 42.5) and used rebuild kits to freshen up the carbs. Found #3 float to be sticking, but it freed up once removed and reinstalled. Adjusted floats to 25mm height per the manual, and checked the float movement after putting the bowl back on on #3 to make sure it wasn't sticking anymore.

Today I once again tried my luck in getting in running. Bike started, but ran rough. White smoke came out the right side pipe for about 20 seconds, then stopped. Lots of white smoke came out of the left side pipe, so much when slightly revving it that I had to shut it off.

Plugs #1+2 were black and sooty, as was plug #4, figures, it hasn't been synced/tuned so it's running rich. Plug #3 was wet with fuel, and the header from cylinder #3 is much much cooler than the other pipes, it doesn't even hiss when touched with a wet rag. I also think the tiniest bit of fuel came out of the #3 pod filter again, but I didn't see it, only the residue on the crankcase afterwards.

Anyone have any ideas on what is going on? Coils wires and plugs/plug wires are all new, so I'm pretty sure it's not spark related. It's a 79 so I didn't have the octy, I had the fuel lines connected to the lower ports on the T-fittings on the carbs, and the upper ports vented to atmosphere.

Also there are two ports on the petcocks, one facing down for fuel, and one facing the front of the bike. Do these vent to the air? I seem to remember them being hooked up to the carb boot ports on cylinders #2 and #3 but I'm not sure (the ports on boots #1 and #4 are capped).

I'm drawing a diagram of my fuel/vac line setup and I will scan it in after work so people can make sense of my babbling

So in short, I think I need to re check all my fuel and vac line routing, figure out why cyl #3 isn't firing correctly. Any ideas based on what I've said??

[oseaghdha]

Greetings from Shanghai

Set your floats at 25.7MM from the sealing surface of the carb, not the gasket. 25MM is too low (actually high because its upside down).

If you do not have the octopus, cap the front nipples on the petcock. Cap all the vac ports on the boots. The one on #2 carb body, is the vac advance, and the only vac connection.

If you do have the octopus, remove it.

Set your idle crews at 1.5 turns out.

Fill the carbs, then turn off the gas to see if it will run, that will isolate any problem with the float needles, assuming the petcocks are working properly.

[John]

Check to see if the float drop is to excessive and allowing the float needles to bind in the seat.

[ejoy1220]

Originally posted by oseaghdha
Set your floats at 25.7MM from the sealing surface of the carb, not the gasket. 25MM is too low (actually high because its upside down).

If you do not have the octopus, cap the front nipples on the petcock. Cap all the vac ports on the boots. The one on #2 carb body, is the vac advance, and the only vac connection.

If you do have the octopus, remove it.

Set your idle crews at 1.5 turns out.

Fill the carbs, then turn off the gas to see if it will run, that will isolate any problem with the float needles, assuming the petcocks are working properly.

I believe it was set to 25.5mm from the base of the carb, not the gasket, sorry I only wrote 25

I'll cap the fronts and the nipples on the boots (those are what I'm going to use when I connect the manometer to sync, correct?) I also did not have the vac advance line connected to the #2 carb body, whoops, how much will that affect how it runs/idles??

Octy has been removed, or it didn't have one (79 1100F), I'll set the idle screws when I try tomorrow.

What do you mean fill the carbs then shut the gas off? Run the bike until the bows fill with gas, and then shut the petcocks off? Is there an OFF position for the petcocks, I only remember FUEL, RES, and ON, I can't remember if there was an OFF on the petcocks. What exactly will I be looking for when I do this, if fuel is still flowing, indicating a bad petcock??

Originally posted by John
Check to see if the float drop is to excessive and allowing the float needles to bind in the seat.

Do you mean check for this?

[oseaghdha]

Sorry

I thought you had a Special.

I see it is an F which has vacuum petcocks(?).

Never mind, I just woke up on the other side of the planet. Need more coffee!

Ignore everything I said about vacuum lines.

[ejoy1220]

Re: Sorry

Originally posted by oseaghdha
I thought you had a Special.

I see it is an F which has vacuum petcocks(?).

Never mind, I just woke up on the other side of the planet. Need more coffee!

Ignore everything I said about vacuum lines.

Gotchya. I'm running pod filters and ditched the stock airbox, should I still cap all the nipples on the boots and the front nipples on the petcocks? The only one I want connected is the vac advance on the #2 carb body.

I also have a vac line coming from the left side of the crankcase, is that just a vent? There is another, much larger vacuum line coming from the top of the crankcase under the carbs that used to go to the stock airbox, what do I do with that, let it vent??

[petejw]

just out of curiosity,
did u ride the bike after u put
on the exhaust/ pod filters.
or did u just rejet and hope 4 the best.
there are times when u dont need to rejet,
mayb ur original jets may surfice..

[egsols]

The vac line running from the left side of the crankcase is your vaccuum advance. It needs to be hooked to the brass port on the engine side of the no. 2 carb.

The large one from the top of the crankcase is your crankcase vent. Yes it needs to be vented. You may want to add a filter to it to keep crap out of the motor.

If you cap the front petcocks you will only get fuel in the prime position.

[tiredoffixing]

I had the same problem. I found out that one of the float valves was binding and not closeing right. After a lot of help on this forum and alot of re doing I finally got it right. I cant say enough about the guys (and gals) on this sight

[ejoy1220]

Had the day off from work yesterday so I dedicated it to the bike, despite the 90* temperatures. I actually like working in the heat, go figure.

Got the vacuum and fuel lines wrapped up, and tapping on the bowl on carb #3 unstuck the float and now it's firing perfectly on all 4 cylinders. Idles like a dream, and fires right up. Battery was charged last night as it had almost no juice left from idling all day.

Rode it for the first time yesterday too. Now I just have to put the battery on a trickle charger and sync the carbs tomorrow and bleed the brakes.

Oh one more question regarding vac lines. The carbs have two ports between the two banks, one for fuel and one for air. Both fuel lines are connected, but where do the air lines connect? right now I just have them venting, and it doesn't seem to be hindering the bike at all.

[psycoreefer]

You've got it right, the two carb vent lines just need to vent to air. Their purpose is to prevent a "vacuum" from forming in the bowls as the fuel is sucked out. You can run them up out of the way and leave them open, or put a small filter on them to keep junk from getting in. On a stock setup the connect to the airbox.

[oldyam80sg]

Originally posted by ejoy1220
Had the day off from work yesterday so I dedicated it to the bike, despite the 90* temperatures. I actually like working in the heat, go figure.

Got the vacuum and fuel lines wrapped up, and tapping on the bowl on carb #3 unstuck the float and now it's firing perfectly on all 4 cylinders. Idles like a dream, and fires right up. Battery was charged last night as it had almost no juice left from idling all day.

Rode it for the first time yesterday too. Now I just have to put the battery on a trickle charger and sync the carbs tomorrow and bleed the brakes.

Oh one more question regarding vac lines. The carbs have two ports between the two banks, one for fuel and one for air. Both fuel lines are connected, but where do the air lines connect? right now I just have them venting, and it doesn't seem to be hindering the bike at all.

[oldyam80sg]

[You said the battery needed to be charged from idling all day.The battery should not have been drained from being on all day.Think about it- if i go for a ride that lasts 12 hours are you saying that it has to charge again.I think that you might also have a charging problem.

[ejoy1220]

Originally posted by oldyam80sg
[You said the battery needed to be charged from idling all day.The battery should not have been drained from being on all day.Think about it- if i go for a ride that lasts 12 hours are you saying that it has to charge again.I think that you might also have a charging problem.

Well the battery had been sitting for two weeks prior, and the majority of the time I was hooking up a jumper pack just to get the bike to start, the battery didn't have much of a charge after so long.

So I brought it home and threw it on a large charger and should be good for tomorrow when I go back

[oldyam80sg]

Just curious how old is the battery? My SG sat in a storage unit for a while until i was able to get the bike to run well enough to bring it down to work on it at my Moms house.Even then i must have started it at least 30 times and it still had enough juice in it to start when i finally went back after 2 months.If i start my bike in May and don't run it until September it will still start with a good battery.