Tuning after first start up-'47 Chief

[Xtracho]

As many of you have followed my posts about the Chief, you know that last month I fired her up for the first time in 30 years. Now back home for a month, I've changed out the head gaskets and found and corrected a stuck exhaust valve on the front cylinder. Fired her up again today and she runs better. But, being as how I'm new to these wonderful bikes, I'm having some issues with tuning and getting the idle set. Once I got her running today, the motor wants to stall when I roll the throttle. Like it wants to flood I think. Also, I cannot open the choke up all the way without the motor stalling and stopping. From just a newbie standpoint I would guess that fuel/air mix is the issue that needs to be addressed. But I'm not sure how best to address that and reach the point where I get proper response when rolling over the throttle. Could I have an intake leak somewhere that affects the fuel/air mix? I replaced the gasket between the carb and intake manifold. Might there be a leak where the intake manifold connects to the cylinders? Very pleased that I have her running again on both cylinders. And I will post a video tomorrow of the bike running to show what happens when I try to use the throttle. Perhaps that might help you experts help me to diagnose the problem and what I must do to address it and fix it. In the meantime, I would be very grateful at the opportunity to tap your knowledge of the problem and how best to address it.

Thanks in advance!

[T. Cotten]

Mark!

The absolute test for vacuum leaks is simple:
http://virtualindian.org/11techleaktest.html
Bubbles will tell exactly where and how much a leak may exist, if any.

Good luck!

.....Cotten

[hairynob24]

Mark did you rebuild the carby ? i have seen the throttle disc placed the wrong way before similar effect ? Rob

[Xtracho]

I did not entirely rebuild the carb. And if you are referring to the disc at the back of the venturi....no I did not mess with it. But will check it just to make sure.
Thanks!

[T. Cotten]

Mark!

There are critical places within the carburetor than cannot be cleaned without complete disassembly.
Aside from that, Linkerts have been reported to run "fine", even though the throttledisc and/or venturi were installed backwards.

Carburetors are enormously forgiving, but manifolds are not.

Do you have an air compressor?

.....Cotten

[pisten-bully]

Do you have an air compressor?

.....Cotten

Mark, suspicions about manifold leaks are wise, so doing a leak test as Cotten suggests is wise also... at least so you can rule that out (or in as the case may be!) If you've got compressed air that's good, for me I simply purchased a large rubber stopper from the hardware store that fit tight in the flange that the carburetor mounts to, drilled a hole in the stopper and with a rubber tipped blow gun put the air to it that way. Probably should have built a plate! Oh, and tighten the manifold nuts, try running it again and see if the problem is still there.

[Xtracho]

I pretty much removed and disassembled the carb entirely. The only piece I did not mess with is the venturi and that throttle plate. New float, new crush gasket for the bowl nut. I have no fuel leaks.

I do have a compressor and will pick up a stopper from the local h'ware shop. I suppose a large crescent wrench will suffice to tighten the manifold nuts at the cylinders? Honestly, if there is a leak that would be about the only spot where I could imagine there being one.

Of course, if anyone has any other areas I should check for leaks let me know.

[T. Cotten]

I pretty much removed and disassembled the carb entirely. The only piece I did not mess with is the venturi and that throttle plate.

Any stone left unturned, Mark,....

Let us know how it goes!

...Cotten

[hairynob24]

Mark i know its a pain in the ass to take the carby off ,did you use a sealant on the gasket to the manifold ? if so the gasket may get broken taking the carby off but that nothing . 20 minute job ,the throttle disc has a # 13 on it ,in the closed poistion the 13 should be on the right hand sidecarby.jpg

[tomfiii]

Did you remove plug at mounting flange and clean channel to idle port.

[Xtracho]

Just completed the "leak test" on the bike this morning. Plugged the hole with a rubber plug and put 20 psi air through. After spraying soapy water on the intakes where they mount to the cylinders I found that there were no bubbles. Indicating that there were no leaks. There were, however, a few bubbles coming from one of the valve covers on the front cylinder. Tightened that up and no more bubbles. I also sprayed the head bolts and around the head gaskets that were replaced. No bubbles there.

When I replaced the gasket where the carb meets the intake I did not use gasket sealant. And I did not pay a lot of attention to the position of the throttle plate but did notice that it does open all the way when I roll throttle. The real pain for me in removing the carbs is pulling the fuel lines. I am actually thinking about just getting rid of the copper fuel lines and replacing them with rubber fuel lines for the time being. Much easier to work with. I have already had to rebuild those copper lines and solder them all back together. Not a big deal there, but fitting them back where they match up with the connections without screwing up the copper lines is a pain in the ass. I suppose I could just remove the lines from the fuel and reserve tanks and pull the carb as an entire assembly.

Right now she is sitting outside in the sun warming up. Cold here on the panhandle last night. Going to let her warm until this afternoon and try to fire her up again. Hopefully I'll see some progress in how she runs and be able to roll on the throttle without her wanting to stall out. We shall see.

I am grateful to all for your assistance and excellent advice. My learning curve is getting better day by day with your help.

[pisten-bully]

JRight now she is sitting outside in the sun warming up. Cold here on the panhandle last night. Going to let her warm until this afternoon and try to fire her up again. Hopefully I'll see some progress in how she runs and be able to roll on the throttle without her wanting to stall out. We shall see.

Mark, you've likely already done this, but re-adjust your two needles before starting, just as the Indian Rider's Guide says, gently seat the needles by turning them in clockwise, then for the low speed needle turn it out counter-clockwise four turns, and for the high speed needle turn it out 1 1/2 turns. Those settings might turn out to be a little rich after all is said and done, but they are a good starting point.

[Xtracho]

Thanks Harry...did you get my PM about the tires? Still cold here on the panhandle and did not get a chance to kick her over yesterday.

[Xtracho]

Morning All. Out early this morning to fire her up. She will run up to full RPM's for about 3-5 seconds then stall. I tried several different combinations of throttle/spark advance/choke position/hi-lo needle settings....all with pretty much the same results. Today I'll be pulling the fuel lines(again) and replacing one copper line from the tee to the intake side of the filter bowl. That one got pretty twisted up trying to get it to match up with the threaded nipple that goes to the filter bowl. Wonder if all those kinks may be causing fuel starvation? I will say that she did run the other day for an extended period of time but trying to roll the throttle caused her to want to stall. I did the intake leak test as recommended and found a small leak at one of the valve covers on the front cylinder. Fixed that (at least I saw no more bubbles.)

Anyhow, and I hate to be a pest, I am asking for your expertise on diagnosing the possible issues that may be causing her to run for just a few seconds then shut down.

[tfburke3]

Morning All. Out early this morning to fire her up. She will run up to full RPM's for about 3-5 seconds then stall. I tried several different combinations of throttle/spark advance/choke position/hi-lo needle settings....all with pretty much the same results. Today I'll be pulling the fuel lines(again) and replacing one copper line from the tee to the intake side of the filter bowl. That one got pretty twisted up trying to get it to match up with the threaded nipple that goes to the filter bowl. Wonder if all those kinks may be causing fuel starvation? I will say that she did run the other day for an extended period of time but trying to roll the throttle caused her to want to stall. I did the intake leak test as recommended and found a small leak at one of the valve covers on the front cylinder. Fixed that (at least I saw no more bubbles.)

Anyhow, and I hate to be a pest, I am asking for your expertise on diagnosing the possible issues that may be causing her to run for just a few seconds then shut down.

I think I would check float operation.What I do is remove the float bowl and reconnect to the gas linet swung out away from carb,sitting same level as installed.Now you can see the float.Hold a piece of gasket paper firmly under the big hole in bottom and turn on gas and observe level,which yours may be to low.
This will also show fill rate to help diagnose clogged lines ,filter needle and seat etc.
Tom