Another startup problem - carbs

[Courtney]

In the morning when trying to start the 80 Special I turn on my petcock (no octopus) and pull the choke out to full. I then crank it and it seems to crank for about 5 seconds then will fire on one or two, but sputters and dies so I repeat this about 10 times. If it finally runs I let it go for a bit and rev it to "clear" it stumbling. Half choke doesn't seem to do much. However once it seems to be running on all four it's fine. I then take off and it is faultless with great power and great idling. Plugs are the correct brown/tan color. It's only the startup, so I'm thinking it's the enrichener circuits. I know this question gets asked dozens of times, and I've searched for it and read them. Guess I just want someone elses advice on my thinking it's the cold start circuit (I didn't disassemble the two middle carb choke plungers because I was an idiot and wanted to ride the damn thing.) These are the plungers attached to the lever linkage I'm talking about.

[James England]

I'd say it is the enrichment circuits but it sounds like you need to do a proper carb clean to get things right.....and, really, to get it right, everything needs to be done x4

[Eastcoaster]

make sure you have the passage in the carb bowl clean sometimes it takes me forever to get it clean and clear If you can't shoot carb cleaner through and spray out the hole in the rim of the bowl It's clogged

[James England]

The only proper way to to this is to remove the carbs and give them all a thorough clean. It's surprising how much crud can accumulate on the jets and passages. Also, it doesn't take much contamination to cause a variety of seemingly baffling problems.

[donebysunday]

Has this just started to happen ?
How long does it sit, over night ?
How much time do you give the bowls to fill ?
Do you use center stand ?
Any leakage of fuel from the carbs ?
If parked for a long time on the side stand fuel will want to travel from #4,3,2 to #1 so could be flooding #1,2,3 and no fuel in 4.
No leakage from the drain plugs ?
If any of the bowls are leaking could be draining that/those out of fuel over night ?
Are you using inline filters set in the line so as to act as sediment catchers ?
Just hope to save you a carb pull if you can find the cause on the outside ?

In the morning when trying to start the 80 Special I turn on my petcock (no octopus) and pull the choke out to full. I then crank it and it seems to crank for about 5 seconds then will fire on one or two, but sputters and dies so I repeat this about 10 times. If it finally runs I let it go for a bit and rev it to "clear" it stumbling. Half choke doesn't seem to do much. However once it seems to be running on all four it's fine. I then take off and it is faultless with great power and great idling. Plugs are the correct brown/tan color. It's only the startup, so I'm thinking it's the enrichener circuits. I know this question gets asked dozens of times, and I've searched for it and read them. Guess I just want someone elses advice on my thinking it's the cold start circuit (I didn't disassemble the two middle carb choke plungers because I was an idiot and wanted to ride the damn thing.) These are the plungers attached to the lever linkage I'm talking about.

[TopCatGr58]

Hey Courtney,

Lots of good suggestions, but it does sound like the enrichener circuit isn't flowing well, and the first place it stops is in the float bowl jet. Next, spritzing cleaner UP that brass siphon tube and ensure it's reaching the top chamber where it goes into the plunger chamber. But like you said, it could also be worn O-rings around the end of the plungers which could allow vacuum leaks so as not being able to suck the fuel thru the enrichener circuit as well.

Did you see the images I posted a while back of the ANATOMY of the carbs...where I bandsaw cut several donated(Thanks MACK) carb bodies to show the small paths the fuel and air takes thru the carbs? Just search for Carb anatomy and you'll find them....most thought they were rather enlightening!

T.C.

[Courtney]

The plot thickens- more info for those not bored to death yet.

Many thanks for the suggestions and questions folks. bike is sitting flat, not leakage from anywhere, I turn the fuel valve on and let it sit for about 15 seconds. Has new inline filters as well.
So here is what I learned today after letting it sit for 24hrs.
Pulled out the fuel enrichment lever, turned the fuel valve on, let it sit 15 seconds or so, then crank it. Turns over for about 3 seconds and fires on one or two, gimps along for about 2-5 seconds on 1 or 2 cylinders then croaks. Repeated this 3 times.
So now I tried something different. I pushed in the enrichment lever so there was no choke and then cranked it again and it half fired on 1 or 2, stopped, then just cranked for about 5 seconds with nothing.
I then pulled out the enrichment lever again, and it cranked and fired up quite well, and with feathering the throttle was able to get it to rev through some bogging and finally roar. Then with proper warmup it was idling fine like always. Anymore thoughts on this? Obviously I'm going to take them apart anyway, I want a totally dependable bike, and while they're off, I'm going to reweld one of my splatter-weld exhaust pipe additions for my Harley Muffler.

[Courtney]

Checking it out now TC, thanks!

Hey Courtney,

Lots of good suggestions, but it does sound like the enrichener circuit isn't flowing well, and the first place it stops is in the float bowl jet. Next, spritzing cleaner UP that brass siphon tube and ensure it's reaching the top chamber where it goes into the plunger chamber. But like you said, it could also be worn O-rings around the end of the plungers which could allow vacuum leaks so as not being able to suck the fuel thru the enrichener circuit as well.

Did you see the images I posted a while back of the ANATOMY of the carbs...where I bandsaw cut several donated(Thanks MACK) carb bodies to show the small paths the fuel and air takes thru the carbs? Just search for Carb anatomy and you'll find them....most thought they were rather enlightening!

T.C.

[donebysunday]

So now I tried something different. I pushed in the enrichment lever so there was no choke and then cranked it again and it half fired on 1 or 2, stopped, then just cranked for about 5 seconds with nothing.
I then pulled out the enrichment lever again, and it cranked and fired up quite well, and with feathering the throttle was able to get it to rev through some bogging and finally roar. Then with proper warmup it was idling fine like always. Anymore thoughts on this? Obviously I'm going to take them apart anyway, I want a totally dependable bike, and while they're off, I'm going to reweld one of my splatter-weld exhaust pipe additions for my Harley Muffler.

Letting it sit a LITTLE LONGER TO FILL THE BOWLS after it kept staling and you have a normal start up.
15 seconds to fill the bowls seems short.
1st thing I do is turn on the fuel, so a minute or longer before start up.
Where is the fuel going during that 12-24 hours, on your bike, mine too ? Boiling off ? Evaporating ? Leaking ?

[Radioguylogs]

On gunked carbs, I always have the most trouble with the enricher passage in the float bowl itself. It is hard to get them to un-gunk so the carb cleaner will shoot a good jet through them.

I always clean the brass siphon tube and enricher jets, but I never find any crud up there.

[James England]

Many thanks for the suggestions and questions folks. bike is sitting flat, not leakage from anywhere, I turn the fuel valve on and let it sit for about 15 seconds. Has new inline filters as well.
So here is what I learned today after letting it sit for 24hrs.
Pulled out the fuel enrichment lever, turned the fuel valve on, let it sit 15 seconds or so, then crank it. Turns over for about 3 seconds and fires on one or two, gimps along for about 2-5 seconds on 1 or 2 cylinders then croaks. Repeated this 3 times.
So now I tried something different. I pushed in the enrichment lever so there was no choke and then cranked it again and it half fired on 1 or 2, stopped, then just cranked for about 5 seconds with nothing.
I then pulled out the enrichment lever again, and it cranked and fired up quite well, and with feathering the throttle was able to get it to rev through some bogging and finally roar. Then with proper warmup it was idling fine like always. Anymore thoughts on this? Obviously I'm going to take them apart anyway, I want a totally dependable bike, and while they're off, I'm going to reweld one of my splatter-weld exhaust pipe additions for my Harley Muffler.

It's filthy carbs. The symptoms of dirty carbs seem unfathomable. You need to clean them..

[Courtney]

It's filthy carbs. The symptoms of dirty carbs seem unfathomable. You need to clean them..

Yep, they're all coming apart again James. I need the bike to start when I want it to.

[donebysunday]

Yep, they're all coming apart again James. I need the bike to start when I want it to.

Where's it coming from ?
In line filters mounted so as to act as sediment bowls ?
Some can be bought with magnets but you could add your own.
Ace has a selection of magnets, some so small it's hard to believe they can be so strong.
Tank inspection with dental mirror and led bright flashlight to check those tight corners, especially back by the petcocks.
You can buy fishing lights with led on the end of a flexible shaft at Wally World.
I think I bought those little magnets there too for less in the needle/thread area.
I've gone as far as pushing a couple of these magnets into an inch of fuel line, about a foot of real thin copper wire through holes in the other end of the fuel line and tied off to the cap lock bar on the tank so they don't get lost and you can still close the cap, pull em out in a month or two, see what you catch ?
How long since the tank has been flushed, cleaned ?
New fuel line !

[Courtney]

New everything, except carbs. Didn't clean the enrichment circuit I guess.