Cold Idle tuning

[Vr6jh]

Hello,

Last year picked up a '77 GL1000 that'd been sitting since 82 full of fuel. I've resurrected plenty of 2 (and a couple 4) cylinder 60/70's Hondas from near death so this isn't terribly new to me.

Long story short, Im struggling with the first start, cold Idle. Maybe it's just how these bikes run? It starts right up, I can even start it first kick with the kickstart. But it doesn't sound great. Sounds like missing on a cylinder or two. I can review it past 3k and it stumbles for a second, and noticably clears up and sounds great above 3k. Let it idle back and it sounds rough again. Once it's warmed up it seems to run and idle fine.

It's been completely gone through. Carbs rebuilt with k&l kits, original jets kept where salvageable. A couple of Randakk's parts sprinkled in where the k&l kit fell short.

Valves set, timing set, new plugs, caps, couples checked. Fuel tank was pulled, cleaned, new fuel filter. Carbs synced and well within 1" of each other.

The one thing I haven't done is Idle Tuning. They're set at stock (1.5?) Turns and the off idle "fix"

When tuning the bike in the garage, it seems to run very very rich at cold Idle. I can smell the fuel and it burns my eyes. Randakk's blog indicated to usually need to fatten up the idle, and as mine already seems rich, this concerns me.

I'm looking for some direction. Where to look, what to try. I thought maybe float bowl after sitting, but seems to do the same thing upon restart. Possibly timing related? I believe it's set proper, using the split timing technique, but am willing to admit it's probably not perfect. Help

[winguyjo]

things that come to mind ... floats (as you have said), exhaust (39 years is plenty of time for condensation, gas, oil, insect/mouse debris to accumulate in there); also do the hand test to see whether all 4 header pipes are getting equally hot.

[joecoolsuncle]

gotta get back into the carbs again. check the enricher circuits for cold idle issues, and btw, your mains are too rich. there is no cold idle tuning, as that is controlled by enrichener circuit. once it warms to operating temp, and driven a few miles is where you would tune for idle and then leave it there. you can get lean misfire on a cold engine that is trying to run off the idle circuit, which can give you the sense that it is rich. the bog when you roll the throttle tells you it is lean, as will the exhaust smell when you try and rev it. an EGA will show this.

[Vr6jh]

I've checked and double checked the floats, but maybe I'll breakdown and buy Randakk's tool and triple check float height.

Joe, Ill be honest, I didn't understand everything you said. Can you further explain the enricher circuit? That's not explicitly called out on the carb diagram. What do you mean by my mains are to rich? Or I should say, why do you say that?

The carbs were absolutely gunked up solid. Linkages were seized, floats stuck to the carb itself, bowls full of solidified gas. I didn't think I'd be able to salvage, but hours and hours of cleaning everything with the ultrasonic cleaner, welder tip cleaners, scrub brushes I believe everything should be spotless, but it's certainly possible something dislodged and plugged.

I do have probably 20 miles, plus an additional several hours of runtime in tuning, so it's had a fair amount of fuel run through it.

I should have been more clear, I understand there is no specific cold idle tuning, more so overall tuning the bike to improve cold idle.

I've pulled the carbs off again once, tore apart and couldn't find any issues, but if you can pinpoint something to check in down for it again.

Thanks!

[joecoolsuncle]

the enricher circuit is what most people refer to as the choke. it is not a choke, as it does not choke anything. it enriches (makes run rich) when you move the "choke lever" and this allows the engine to have enough fuel to warm up at a higher idle to come up to operating temperature.
the main jets are too rich, if the main jets were the right size, you would have a bog when you revved the engine, not being happy about the performance of a cold engine. a lot of carburetor kits include jets that have absolutely no correlation to keihen jet numbers. i suggest you install stock main jets as a starting point.

do not suspect anything is not correct untill the engine is absolutely at operating temperature of approx 210 degrees farrenheight. there is no capability to tune keihen or most other carburetors at a cold or even cool temperature. hope this helps and
Merry Christmas!

[Shadowjack]

GL1000s have an old-style choke, which is the flapper plate before the venturi. When closed/partially closed, it increases vacuum through the system to draw in more fuel relative to the air available. They do not have an enrichener circuit with a small knob you lift to let in more fuel like the later bikes.

[dingdong]

the enricher circuit is what most people refer to as the choke. it is not a choke, as it does not choke anything. it enriches (makes run rich) when you move the "choke lever" and this allows the engine to have enough fuel to warm up at a higher idle to come up to operating temperature.
the main jets are too rich, if the main jets were the right size, you would have a bog when you revved the engine, not being happy about the performance of a cold engine. a lot of carburetor kits include jets that have absolutely no correlation to keihen jet numbers. i suggest you install stock main jets as a starting point.

do not suspect anything is not correct untill the engine is absolutely at operating temperature of approx 210 degrees farrenheight. there is no capability to tune keihen or most other carburetors at a cold or even cool temperature. hope this helps and
Merry Christmas!

I believe you may be confusing the OP. On the gl1000 the choke does "choke" the air supply which creates a richer mixture. An enrichener like in the gl1500 does what you describe by adding more fuel to the mixture. Just saying.

[joecoolsuncle]

wow! allow me to offer apologies. i did that ASSume thing! never would have thought a motocycle like a goldwing would use a real choke. and thank yall for correcting me, i will have to start fact checking myself.
Merry Christmas!

[Shadowjack]

Wings were first designed in the early 70s, when pretty much everything used a simple choke and a fast-idle mechanism. And they're notorious for cold-start running issues; we always had to fool around for the sweet spot, working the choke lever with one hand and holding the throttle with the other. I don't recall what the 1100s had, but the 1200 has enricheners. By that time in history, smog rules made the engineers pull their fingers out and make it work right.