In depth carb question

[dtkid]

Hey Guys:

I put a stage III Dynojet kit in the carbs for my 80' GS1100E (K&N pods, 4:1 header). The machine runs and sounds like an aggressive bull in heat.......when I can get it started.

Here is what it is doing:

It runs perfect once I get it started and will run and start all day without a problem, however, once it gets cold it absolutely will not start (I have to roll it down the mountain in the mornings to start it). I know that all components (other than the carbs) are functioning because when I put the carbs from my GS750 (also stage III jetted) on the bike it runs like a dream, but it obviously don't possess the "umph" that it should while running with the GS750 carbs.

The bike will run for a couple of seconds when I choke it (in the morning) but it will not continue to run (with choke or without). I have already burned up a starter and am awaiting ya'lls opinion before I put the 1100 carbs back on.

Could it be as simple as "too rich"? I do have the mixture screws far out but I had to (to keep it from makin' those "lean-pops"). I have enough air-jets and mains to change them around...............any suggestions? I put new pilots in also. I had to use the pilots with the ports all the way up the body although the originals did not have those ports [I don't think it is supposed to matter as long as they are the same size (45)].

I know these type questions are convoluted at best.......but I would appreciate any input, either guesses or experience-based certainties.

[The Kelzer]

I had a very similar problem with another bike. Come to find out a couple of the valves were just a hair too tight and it wasn't getting enough compression for a cold start. DROVE me (like you it sounds) NUTS!

Just because it's only happening after you installed the stage 3 kit, don't rule this option out. If your curious if it's too rich, try starting it w/o the choke. if she wont light then pull the plugs and see if they are wet. then you'll have confirmation.

I bet it's your valves though.

Good luck,
KK

[Carter Turk]

Try putting a pen cap in choke actuating arm or just hold it wide open with your hand. No throttle.

I suppose if you don't have the clutch bypass for starting then you'll have to use the cap.

Maybe the choke knob up by the steering stem isn't opening the choke circuit all the way.

I don't think having the air/mix beyond three turns is a sign of properly set up carbs.

I think popping is the exhaust pulses going back through the intake tract.

I don't think this is related to starting, but did you drill out the slide holes?

[Road_Clam]

Hey Guys:

I put a stage III Dynojet kit in the carbs for my 80' GS1100E (K&N pods, 4:1 header). The machine runs and sounds like an aggressive bull in heat.......when I can get it started.

Here is what it is doing:

It runs perfect once I get it started and will run and start all day without a problem, however, once it gets cold it absolutely will not start (I have to roll it down the mountain in the mornings to start it). I know that all components (other than the carbs) are functioning because when I put the carbs from my GS750 (also stage III jetted) on the bike it runs like a dream, but it obviously don't possess the "umph" that it should while running with the GS750 carbs.

The bike will run for a couple of seconds when I choke it (in the morning) but it will not continue to run (with choke or without). I have already burned up a starter and am awaiting ya'lls opinion before I put the 1100 carbs back on.

Could it be as simple as "too rich"? I do have the mixture screws far out but I had to (to keep it from makin' those "lean-pops"). I have enough air-jets and mains to change them around...............any suggestions? I put new pilots in also. I had to use the pilots with the ports all the way up the body although the originals did not have those ports [I don't think it is supposed to matter as long as they are the same size (45)].

I know these type questions are convoluted at best.......but I would appreciate any input, either guesses or experience-based certainties.

ALWAYS check the SIMPLE things first. Is the choke cable adjusted correctly? All's you want is a slight amount of free play in the cable (about .125"). When the bike does finally light off, do you see dark smoke come out the exhaust? This means the engine is ingesting raw fuel while it is sitting. Try to initially find out if it's getting too much fuel, or not enough.

[dtkid]

I think I may have found the problem.

Here it is for future reference:

I had replaced the air-jet with a 170 because I assumed that since I live at an altitude of 3000ft. the bike would naturally run rich.....thus, I over compensated and allowed way too much air in the mix.

That is why I had to turn the mix-screws so far out. So last night I replaced the 170 air-jets with 115s'. This allowed me to turn the mix-screws down to a reasonable degree and it started right up.

I reckon even an 1100 can have too much carburation...(I'm hangin' my hat on the theroy that the machine was just overwelmed with too much of the correct mixture.) Any takers??

[dtkid]

Oh yeah, I forgot to consider the issues raised:

I was indeed chokin' it by hand cause I can't find a choke cable to fit the carbs. (The choke cable is real tiny at the carb-end cause you have to thread it thru a piece of pipe/conduit before it mounts to the carbs). I changed this last night and used the choke set-up from an old set of GS750 carbs.

If the valves were stickin' or anyway at fault I don't believe the bike would run so well on my GS750 carbs.

Slide holes were drilled (which as stated, should not affect the idle/starting circuit).

As always....thanks bundles for the input. Bouncing ideas is one of my favorite hobbies.

[caberguy]

Bulls don't go into heat, they're boys... c'mon.

[dtkid]

Good point.......how bout' "a bull in the rutt surrounded by 47 naked heffers with sensuously painted lips and french maid skirts squirming at an elevated frequency due to their condition of ovulating during their estrus "heat-consumed" desire to procreate"?

[wiredgeorge]

IF I understand this question, you have rejetted some BS34s using a DJ Stage 3 kit? The bike starts hard?

OK, if that IS the question, the DJ kit has nothing to do with the bikes starter or pilot circuit as they don't give you any hardware that effects these areas. What you DID you was stick pods and pipes on the bike which REALLY lean the air / fuel mix. At start up, the bike MUST MUST have a rich mixture till it warms. Hmmmm... What to do? You have some options like going back to the factory airbox/pipes but more likely you will want to richen the starting circuit mixture and pilot mixture. To do this, FIRST make sure that the choke pick up brass tube that sticks down into the bowl is clear... stick a wire through the little hole. Then remove your bowls. At the bottom is a small hole? Blow some spray carb cleaner through those things and ensure it comes out the other end where the pickup tubes fit into. If you have done that, that is all that can be done with the choke itself. If those things are clogged, you ain't getting the gas needed at choke time... just air thought the choke circuit.

NEXT, look at your GS1100 manual and see what pilot jets are called for. #37.5? #40s? #42.5s? GO UP ONE OR TWO SIZES in pilot jets... If you go up two, keep an eye on your plugs for fouling and don't leave it on choke long but bigger pilots will help you start the beast. I just don't remember what size is used out of the box for your bike. The larger pilot jets will help starting and give you quicker warm ups. Why doesn't DJ give you bigger pilots in the DJ Stage 3 kits? I dunno... since you are using pods/pipes with those applications, they sure should... I suspect it is because it would cut into their bottom line. On some of the kits for NEWER bikes, they put in what they call "air correctors" which partially OBSTRUCT the airflow to the pilot circuit because of the very common issues with regard to starting and warm up.