Bike NEVER starts with choke. Strange.

[Jestercinti]

82 GS450LZ. Previous owner "rebuilt" carbs. So far, I have only adjusted the air screw (although it was **supposed** to be set by the factory he drilled it out) per the recommendation of the Clymer manual for the 1979 model.

The problem is that with the choke set to any level, it never fires up. Take the choke off, give it 1/8 throttle, and it fires up no problem...even at 30 degrees F. Warms up fast, and pulls hard to 80 MPH. Idles fine at 1200 rpm. Brand New OEM Carb Boots, O-Rings, and Clamps. Adjusted valves to spec (they were tight). New Iridium plugs. Air Filter stock, but clean and oiled. Runs tip-top. 120 miles to the tank (2.5 gal) before reserve.

My lawn mower does not start without the choke. All other bikes I had did not start without the choke. Is this set too rich?

Am I worried over nothing, or have I just found my Winter project? I am not the best at rebuilding carbs, but I have all winter to futz with it and I have a good Clymer manual.

What should I do? Any thoughts?

[tom203]

82 GS450LZ. Previous owner "rebuilt" carbs. So far, I have only adjusted the air screw (although it was **supposed** to be set by the factory he drilled it out) per the recommendation of the Clymer manual for the 1979 model.

The problem is that with the choke set to any level, it never fires up. Take the choke off, give it 1/8 throttle, and it fires up no problem...even at 30 degrees F. Warms up fast, and pulls hard to 80 MPH. Idles fine at 1200 rpm. Brand New OEM Carb Boots, O-Rings, and Clamps. Adjusted valves to spec (they were tight). New Iridium plugs. Air Filter stock, but clean and oiled. Runs tip-top. 120 miles to the tank (2.5 gal) before reserve.

My lawn mower does not start without the choke. All other bikes I had did not start without the choke. Is this set too rich?

Am I worried over nothing, or have I just found my Winter project? I am not the best at rebuilding carbs, but I have all winter to futz with it and I have a good Clymer manual.

What should I do? Any thoughts?

I'll assume you actually checked to see that "choke" lever was moving something at carbs. It's really an enrichment system, whereby extra fuel is drawn up to carb throat thru little passages in carb body. These get clogged easy if bike is idle for months. Since it runs well , I'd be happy and plan on carb cleaning this winter.

[DanTheMan]

82 GS450LZ. Previous owner "rebuilt" carbs. So far, I have only adjusted the air screw (although it was **supposed** to be set by the factory he drilled it out) per the recommendation of the Clymer manual for the 1979 model.

The problem is that with the choke set to any level, it never fires up. Take the choke off, give it 1/8 throttle, and it fires up no problem...even at 30 degrees F. Warms up fast, and pulls hard to 80 MPH. Idles fine at 1200 rpm. Brand New OEM Carb Boots, O-Rings, and Clamps. Adjusted valves to spec (they were tight). New Iridium plugs. Air Filter stock, but clean and oiled. Runs tip-top. 120 miles to the tank (2.5 gal) before reserve.

My lawn mower does not start without the choke. All other bikes I had did not start without the choke. Is this set too rich?

Am I worried over nothing, or have I just found my Winter project? I am not the best at rebuilding carbs, but I have all winter to futz with it and I have a good Clymer manual.

What should I do? Any thoughts?

As far as I know, everybody on this forum when they rebuild their carbs drill out the caps on the air screws so they can be properly adjusted instead of EPA too lean adjusted. If it starts and runs well without using the choke, so be it. I wouldn't complain. However, you should be able to start it without touching your throttle. If you choke it and try to start it without touching the throttle and it starts, that's the way it's designed to work. IF your spark plugs are black and sooty, the carbs are running too rich and you need to adjust the air screws.

[Jestercinti]

To follow-up, I do need to give it some throttle when starting (more so when it is cold) but still need to twist it slightly when warm otherwise it will crank all day. The Clymer manual says to turn out the air adjustment screws about 1 1/4 turn from tight...but that was for the 1979 or maybe 1978 model...not sure if it has changed for the 1982 model.

Checked the plugs. Slightly dark and sooty, but not horrible. Yep, looks like I am running a little rich. I will try tweaking the air screws, and who knows...maybe a carb dip is in my future And yes, the choke appears to be operating correctly. I do need to use the choke when it has been sitting for an extended period of time (over a week), but that is the only time.

[tejasmud]

To follow-up, I do need to give it some throttle when starting (more so when it is cold) but still need to twist it slightly when warm otherwise it will crank all day. The Clymer manual says to turn out the air adjustment screws about 1 1/4 turn from tight...but that was for the 1979 or maybe 1978 model...not sure if it has changed for the 1982 model.

Checked the plugs. Slightly dark and sooty, but not horrible. Yep, looks like I am running a little rich. I will try tweaking the air screws, and who knows...maybe a carb dip is in my future And yes, the choke appears to be operating correctly. I do need to use the choke when it has been sitting for an extended period of time (over a week), but that is the only time.

Yep, I have had bikes do this same thing not needing the choke to start. You are correct in your analysis. That is exactly what is causing it, being a tad rich. Just tweak the air screws. Manuals will state a value for where the screws need to be set, but this is not an absolute number. It will vary slightly from bike to bike of even the same model.

Quote;
"The Clymer manual says to turn out the air adjustment screws about 1 1/4 turn from tight..."

The practice of "lightly seated" on any type of metering screw is a good idea. Never "tight."

"Tight" deforms the tips of the metering screws in most cases.

I usually set carbs up to need about 1/2 choke on the initial start without having to touch the throttle during the hottest time of the year in summer. It fires over, then turn the choke off and it starts right up. In the summer the bike will not run with the choke on at all, but needs it to be applied to get it to fire over initially. In the winter it needs the choke to fire up, and it will run on choke for a minute or so.

You say it runs good, IMHO I wouldn't do anything but tweak the air screws. If there is no history as to the carbs being rebuilt might replace the o-rings and such.


E

[Jestercinti]

Well, yesterday I backed out the AIR screws again. This time I loosened them 1 1/2 turn instead of 1 1/4 turn. This morning I started the bike with 1/2 choke, no throttle...it was 35 or so degrees in Cincinnati. Barely touched the starter button and it fired RIGHT up like it is supposed to. I let it warm up for about 45 seconds, took off the choke, and it ran like a DREAM. It ran fine before, but now it runs even better.

Thanks everyone! I appreciate it!