Starting a cold engine

[scdmarx]

The 83I seems to run well when warmed up. (best I can tell) but I'm not real satisfied with the cold starting. I'll try to describe the procedure to complete a successful cold starting event:

1. Turn on the gas.
2. Turn on the ignition.
3. Push the start button. (it has one chance to come to life)
4. If we experience "spontanious combustion", then I quickly move the choke to the fully closed position and hope it stays above 1500 rpm for a moment.
5. Just about time I become confident it will stay running, the rpm soars to 4000. When it gets to 4500 I back off the choke and hunt for the happy spot somewhere around 3000 to 4000 rpm. During this time there is a lot of intermittant popping going on from both the intake and the exhaust. The rpm will drift up, then drift down. I have to babysit the choke lever or it will slowly fall asleep and die, or it will slowly rev up and explode.
6. Soon as the temp gauge looks like it's starting to move a little, I can adjust the choke to an idle of about 2000 rpm. It will stay there steady while I get myself jacketed, helmeted, goggled, and gloved. Then I can shut the choke off and ride. All is well.

If I screw up the routine, then it acts flooded, and there have been some times when I ran the battery down before snapping out of it. So it's a very critical routine.
The longer it sits, (overnight soak) the worse it is. If it only cools for a few hours, then I still have to go through the routine, it's just not near as difficult. After it's warmed up, you almost don't even hear it crank over, it starts up real nice.

I've never had these carbs apart. Many, many years ago I had gone through a few Mikuni's and SU's. But I didn't really understand how all the circuits worked. Just sorta take them apart, clean them, put them back together with new gaskets and pat myself on the back when they work. On the other hand, I have gone through so many Quadrajets, 4barrel Holley's I can almost do them blindfolded.

Anyways, before I decide to start tearing into another project, does this sound like a carburator problem to you guys? Or...how do I approach this?

All thoughts and opinions are welcome because...well....I'm not sure and you guys are smarter than me.

 

[dan filipi]

When it acts "flooded" have you tried giving it full choke?
I ask because it may be it's lean and not flooded.

Mine without choke will not start when cold.
It may fire a couple times but that's about it.

Starting I crank to get some oil around then pull full choke to start.
It will race up to 3-4k then after 10-15 seconds the rpm will start to drop slowly, that's when I start taking the choke off to where it smooths out then after a minute or so take choke completely off. At that point it usually idles a bit slow but speeds up gradually as it warms up.

I've been thru my carbs with a complete seal kit and cleaning.
I don't know if it's running like it should when cold but it's acceptable.

(Topic moved to 1100 Tech Forum)

 

[slabghost]

that works for me.

 

[Omega Man]

You know, your bike sounds like mine in the am with the choke dance, and soft popping front and rear.

~O~

 

[mcgovern61]

My carbs are rebuilt and I always have to choke before starting except when hot.

Cold start, (as long as the choke is fully closed) will start instantly. But try it cold with the choke open and it will start and then stall and then it is a real challenge to start it again. Like Dan wrote, once started it runs up to 4K and I ease the choke choke in. At 3k and as it runs for a minute it will speed back up to 4K. I ease the choke in and drop down to 2K (all within 3 minutes max) and then idle. If it is below 40 degrees, I leave the choke out longer to help warm the engine. During the initial startup, mine also will pop and make noise for about 10 seconds until it is up to 4K (almost like it is trying to clear out gas from the engine).

 

[AApple]

My '81 has an accelerator pump on one of the carbs, so I'll give the throttle a little twist, then pull the choke full out. It will crank for about 1 1/2 seconds before firing off, and idling around 4000rpms. Then, I open the fuel petcock. The idle on mine will come down within 1 minute to around 2000rpms, and I'll back off on the choke then. I also get a few small pops from the exhaust when it first fires, but by the time the idle comes down, it's purrin like a kitten. At that point, I have my gear on, the temp gauge has moved up a bit, and I'm ready to rock & roll.
I forgot to turn the fuel on Wednesday when I left, and about the time I pulled out of the driveway into the street, it started buckin...then I remembered to turn the fuel on! I'm sittin in the middle of the street, tryin to keep it firing until the carbs get fuel. Luckily, no-one was out and about to see me! :smilie_happy: oh2:

 

[scdmarx]

Ok, looks like I'm not the only one living with this problem. Someday I'm gonna have to figure out just how this choke system works by design.
My 82 Standard is just the opposite. I turn on the gas, pull the choke cable, hit the start button and she fires right up. No popping during warm up or anything. Same every time. Very dependable/predictable. Sweet. But with the 83 Interstate when I first go out in the morning and start the "routine" the first thought up front in my mind is will it start and what are my options when it don't. It usually starts now that I'm rehearsed, but the risk increases with the more days it's been sitting, and the colder it is outside. Over the period of ownership, I've tried every combination I can think of. I think I got it down now, but like I said before, I get one shot to make it work. If either one of us miss a beat, then it becomes a half hour chore.

 

[dan filipi]

All the choke really does is close off air flow which causes a higher vacuum which pulls in more gas from the idle circuit.

If it floods easily you could have a weak spark or float levels are too high or low compression.
A clogged air filter could also cause it to run too rich.

 

[mcgovern61]

All the choke really does is close off air flow which causes a higher vacuum which pulls in more gas from the idle circuit.

On mine, where the choke cable connects to the shafts, it has an eccentric that gives the throttle some gas when it is pulled.

 

[Smokey66]

My 82 is the same,but it don`t feel right letting a cold engine buzz at 4000 rpm so as soon as it fires I push the choke back in till it gets down to about 2000,thing is it wont stay there by itself and I have to hold the thing in that position till its warm enough to idle on its own.BUT I only have to use the choke when its less than 70° F outside.Otherwise it starts right away and idles at about 800 rpm(when warmed-up 900 rpm)WITHOUT the choke,even its its been sitting for a week.AND with or without choke,I always pump the throttle two or three times(accelerator pump) before I hit the button.Always fires on the first revolution!

 

[joedrum]

that is a bit much routine to go through....sounds like carb work in the future if they dont get cleaned up on there own .....poor ignition ....who knows your just getting started learning this one .....i think my 83 is about the same way .... :mrgreen:

 

[Omega Man]

My 82 Standard is just the opposite. I turn on the gas, pull the choke cable, hit the start button and she fires right up.

Same here, my old girl starts in 1 second, but I do get the snorts and huffs. Also, I don't turn on the gas until after she fires. One day I turn the gas on first and immediately smelled gas...she flooded instantly, however this was only once, and not an ongoing problem.

~O~

 

[SteveA-wing]

My 82 Standard is just the opposite. I turn on the gas, pull the choke cable, hit the start button and she fires right up.

Same here, my old girl starts in 1 second, but I do get the snorts and huffs. Also, I don't turn on the gas until after she fires. One day I turn the gas on first and immediately smelled gas...she flooded instantly, however this was only once, and not an ongoing problem.

~O~

On my '81, I open the petcock, give the throttle a twist and set the choke to full, and it starts with the first bump of the starter. Same deal, RPMs run up to 3K or so, and I then open the choke about 25% and drop the RPMs to 2K then every 15 to 20 sec. will open the choke a little more to keep it around 1500 to 2k. Usually the choke is fully open in a minute if the weather's warm, 2 - 3 minutes if it's in the 40's.

 

[dan filipi]

I did up a video this morning of mine.

This is starting after not having been run all week. 56 degrees in the garage.

At first there was no choke on which fired a few times then quit.
Then full choke to start.
I left full choke on until near the end when I pulled it completely off to idle which is kind of lopey and not smooth for a few minutes til I see the temp needle move.

It floats up and down in rpms even though I never touched the choke or throttle.
Dunno why it does that.
Sometimes I'll fiddle with the choke a bit to get a smoother fast idle.
The smoke is atf.


[flv]https://filipi.com/startingcold.flv[/flv]

 

[CBH]

Most of them must act like that on a cold start up. Mine is the same way. Sometimes fires right up with the choke pulled, but most of the time takes a few seconds of cranking, then I have to play with the choke slightly until she gets warmed up a bit. Mines doesn't sputter though, it just wants to slow down and die until it warms up, which only takes a minute or less.

 

[mcgovern61]

thing is it wont stay there by itself and I have to hold the thing in that position till its warm enough to idle on its own.

If you adjust the nut under the choke handle, you can tighten it so that it will stay where you put it. :yes:

 

[Omega Man]

thing is it wont stay there by itself and I have to hold the thing in that position till its warm enough to idle on its own.

If you adjust the nut under the choke handle, you can tighten it so that it will stay where you put it. :yes:

On some wings this is just not true, I've read it many times and wanted to say something but didn't. IDK...maybe on less weathered wings with fewer miles, but mine no longer works. Nothing is broken or stripped, the nut just doesn't hold my choke in place. I guess I never mentioned it before because it wouldn't help me anyway, I have to constantly move my choke during warm-up. Luckily warm-up on a below freezing morning is about two minutes.

~O~

 

[slabghost]

Some choke cables are twist lock. Pull and twist about 1/4 turn clockwise. My 81 starts best full choke no throttle.

 

[danf]

I thought I was the only one this happened to, it sounds pretty typical to me..Cold blooded I guess..

 

[Omega Man]

Thanks Slabghost! The cable will hold if I twist to the right.

~O~