Carb Noob

[cowboyup3371]

Basscliff,
I'm looking at building one of those myself; is yours strictly gravity fed or do you have to do anything to prep it when you hook it up to the bike?

[MisterCinders]

BassCliff:

Does that bottle come with a cap that accepts a fuel line connection? If not, how did you fashion that part of the rig?

[Dave8338]

BassCliff:

Does that bottle come with a cap that accepts a fuel line connection? If not, how did you fashion that part of the rig?

The Gear Lube (all that I've ever used) comes with a tapered pour spout that the hose just slips over, rather tightly, and then you can use a barbed nipple like the brass one Cliff shows, to either step up or down on the final fuel line fitting size.

Also notice the use of a golf tee, to block off the vacuum port on the #2 carb. YOU NEED A GOLF TEE, no other device will work. lol

[MisterCinders]

The Gear Lube (all that I've ever used) comes with a tapered pour spout that the hose just slips over, rather tightly, and then you can use a barbed nipple like the brass one Cliff shows, to either step up or down on the final fuel line fitting size.

Also notice the use of a golf tee, to block off the vacuum port on the #2 carb. YOU NEED A GOLF TEE, no other device will work. lol

What is the part no. for that golf tee? I cannot find it in any of the fiches.

[BassCliff]

The Gear Lube (all that I've ever used) comes with a tapered pour spout that the hose just slips over, rather tightly, and then you can use a barbed nipple like the brass one Cliff shows, to either step up or down on the final fuel line fitting size.

Also notice the use of a golf tee, to block off the vacuum port on the #2 carb. YOU NEED A GOLF TEE, no other device will work. lol

Very observant Dave, thanks. A golf tee works best but other objects will suffice.


Thank you for your indulgence,

BassCliff

[KEITH KRAUSE]

I've always used the tank for a reservoir. Just place it on a workmate and add longer lines. But whatever you use be sure it's VENTED well so fuel will flow.
As for the rebuild kit mains, I don't know what manufacturer made them but be aware that not all makers size their jets the same way. For example, Dynojet sizes their jets by the actual size (diameter) of the hole. Mikuni sizes theirs by how many CC's flow in a minute. That's why a 130 Mikuni main jet is approx' the same as a 138 DJ main jet. Hopefully your kit really is the same as a 102 Mikuni.

[MisterCinders]

With my new valve cover gasket, I put the bike back together with extended fuel lines to the separate tank full of fresh gas. Ready to move forward with final adjustments and synching, I went to start her up.

At first, starter spinned but engine would not start. After some trial and error (mostly error) I determined that I was turning the idle screw the wrong way, thinking "lefty-loosey" would "open" the idle.

Once I got that straight, I dialed in the idle screw this morning and gave it a go.

With choke, the bike starts and idles at about 1,500. The weather is cooling off, but I find it odd that the idle is so low with choke. Adjusting the idle screw did not seem to encourage the idle speed above 1,500.

Bigger problem is that when I give it any throttle, it dies.

I also see that the float plugs are leaking a bit. Not a surprise because two of them were bowls that could not be separated from the plug and, therefore, still have crappy o-rings. I have new float bowls and will replace the bad ones with new o-rings.

When I rebuilt the carbs, I had little confidence in the air and fuel jet settings. Perhaps over-cautious, I was too squeamish to fully bottom out the screws at first. Realizing that error midway and generally skeptical of the prior settings, I set the pilot fuel jet to 1 turn from gentle bottom and the side air pilot jet to 1 1/4 turns from gentle bottom.

Recall the other stages of this saga:

Intake Boots are good and have new O-rings.

Valves are set to spec.

Airbox has new filter and looks pretty tight, though it is missing the snorkel.

While I get the concept, reading the symptoms of rich and lean baffle me. Is this starting problem a function of the air/fuel jet settings? Any ideas on how I can dial those in?

[MisterCinders]

Fired it back up tonight, same results.

A WD-40 test did not reveal any air leaks.

The No. 4 exhaust is ice cold.

Guess I am tearing her back down again. FML

[Big T]

Before you take the carbs off, do two things:

1. Check you spark plugs - are all of them wet? Esp #4?
2. Swap plug wires #1 and #4 and see if the problem stays at #4 or moves to #1

[MisterCinders]

Now I cannot even get it to start. Starter spins but it won't turn over.

[Suzuki_Don]

Bigger problem is that when I give it any throttle, it dies.

The engine will die if you use the throttle at all while the choke is in use. You can only use the throttle once the choke has been fully turned off.

[MisterCinders]

Pulled the carbs, changed out the float bowls and adjusted the fuel pilot screws to one turn from bottom. Re-did the bench synch. Checked the passages and they are clear.

Oiled the air filter lightly because it seemed a bit dry.

Put it all back together.

Bike starts and idles at 1500. Warmed it a bit and maintained idle without choke.

Any more than a hair of throttle, dies.

No. 4 cylinder doesn't fire. Exhaust for No. 4 is ice cold.

Swapped the leads and got the same result. Cold exhaust on No. 4.

Checked the plugs (which are new) for Nos. 1 and 4. 1 is dry and dark. 4 is dry and white.

The exhaust on 1 and 2 gets very hot after idling for only a minute or so. It is very cool (below 50 F), but after a minute or so of idle there is a light smoke drifting off of the head/exhaust point. Killed the engine at first sign of this, let it cool, and started it again. Same result. Idles for a bit, gets warm (except for No. 4) but dies with throttle. Again, this is without choke.

Running out of ideas at this point. I have gone completely through the looking glass here on the mechanic side (I have no skills, you see), but cannot fathom what is going on here. Am I making things worse??

Should I concede defeat and get it to a shop? Any Chicago GSers around to help solve the mystery?

[MisterCinders]

Bumping with a very basic question.

How the hell do I tell is this problem is rich or lean? I can't rev it enough (i.e., at all) to check compression or to get much of a plug reading.

On the one hand, death by throttle strikes me as a rich problem. OTOH, the throttle also increases the air flow, so it could be lean.

Is my bike Jack Sprat or his old lady?

[koolaid_kid]

"Normally" what you are describing is a lean condition. Is there fuel in the bowl for the #4 carb? Can you check to see if you are getting spark on #4? The easiest way is to use an inductive timing light because you don't need to move any wires. AutoZone might rent one to you.
I suspect #4 carb is not getting any fuel, but the only way to check is to remove the bowl. If you pull the carbs again, do this. Pull the carbs, remove the #4 bowl, reconnect the fuel line and turn the petcock to Pri. If fuel does not flow at all there is the problem. If it does flow, I would then check the float level.
Best of luck.
AFA a remote fuel reservoir, I went to AutoZone and purchase a plastic overflow tank for a radiator. $8, has 3 nipples on it. I used one to connect the fuel line to the carbs, and another for a vent.

[MisterCinders]

OK - plan of action now is:

1. Check the No. 4 plug for spark (please be this easy );
2. Check again for air leaks with spritz of WD-40 or carb cleaner;
3. Check for lean by hand covering the airbox while idling (mechanic suggestion);
4. Check for rich/lean with some idle jet adjustments;
5. Pull carbs and check float levels; and
6. Reclean carbs, spray out all jets, check all passages; and
7. Perform ancient ceremonial witch man ritual.