25 Buick final adjustments

[carmover]

I finally got the 1925 Buick cranked again with the valves set at 010 cold and ran it until it got warmed up and adjusted all valves at 006 hot.I started the car with the air adjustment knob flush with  the ratchet and the fuel adjustment open one turn  and stopped with the notch lining up with the post.Once running I opened up the air until the engine rolled and ran the air in until it ran it's smoothest at idle.It was running and idling smoothly but when I cracked the throttle it hesitated and back fired through the carb.Is it too rich or too lean?Nothing I have tried has given good throttle response and smooth running .when I give it throttle.

 

 

Edited April 19, 2018 by carmover (see edit history)

[raydurr]

Typically a backfire through the intake indicates a lean condition. Sometime my 29 likes to pop back unless the choke is slightly pulled out. After some driving the condition usually goes away.

[Gary W]

Running lean.  You may also get that as you shift between the gears.

[carmover]

When I put the air knob about even with the ratchet and the fuel valve open 1 turn and lining it up with the pin it idles and runs its best but when I step on the throttle it hesitates and kicks back.If I give it more air I get better throttle response but when I bring it to idle it starts running rough and won't idle. 

[Hubert_25-25]

Ron, 

    I know you have a fresh motor.  Just to rule a few other things out.

If you put a vacuum gauge on the car while it is idling, what reading are you seeing.  I want to ensure we don't have any breathing issues.

Have you put a dwell meter and a timing light on the car to ensure that the dwell and timing are correct.  I know that they did not have dwell numbers in those days, but someone knows what the dwell should be for our cars.  That would resolve that the spark is in the right place.  

Is your carburetor heater valve in the exhaust open?   Hugh

 

[Larry Schramm]

Here is a chart that should be helpful to determine what problems you might have and what they are using a vacuum gauge.

[carmover]

4 hours ago, Hubert_25-25 said:

Ron, 

    I know you have a fresh motor.  Just to rule a few other things out.

If you put a vacuum gauge on the car while it is idling, what reading are you seeing.  I want to ensure we don't have any breathing issues.

Have you put a dwell meter and a timing light on the car to ensure that the dwell and timing are correct.  I know that they did not have dwell numbers in those days, but someone knows what the dwell should be for our cars.  That would resolve that the spark is in the right place.  

Is your carburetor heater valve in the exhaust open?   Hugh

 

Hugh I have the heat pipe blocked off at the carb.I am going to get a vacuum gauge and do some checking .The butterfly in the heat riser is missing,it has never had one since I bought it.How do you check the dwell on one of these old cars ?I have been thinking about trying a timing light on it ,when I timed it I did like the book said and closed the number one intake valve and kept turning until the 7 degree mark lined up with the spark retarded and then lined up the rotor to number 1 and it started right up.I let it warm up and adjusted the valves to 006 hot and then adjusted carb and had it running smooth and idling well and let it run for about an hour it ran cool with good oil pressure and was oiling the rockers good.I thought I had it in good shape untill I went to put it up.When I got in and pushed the accelerator pedal it hesitated and ran rough.I have rechecked the valves and they are set just right.

[sligermachine]

A dwell meter will show you a lot . just get a cheep one 2 little clips to the coil  from what  I remember  .Im  in Montana or I would put a picture of mine on here for you  24.00 good investment set the  point gap with it better than a filler gauge . More accurate way to  adjust for wear and can see timing variation problems with it . Super simple to use comes with a chart to tel you what it is saying to you . - kyle

Quote

 

 

[Brian_Heil]

By all means use a dwell meter and a timing light. 

 

Most timing lights are 12v so power it with a 12v source. I roll the 12v lawn tractor over and steal 12v from it. 

 

The timing mark is tough to see on the top of the flywheel. Make sure your advance lever is fully retarded when setting timing. 

 

There is a detailed description of all this covered on this site. 

[Brian_Heil]

I will get in trouble for my next comment by someone but I often have trouble getting the dwell correct with the threaded points and lock nut arrangement. Very small and I always overshoot my desired change in gap/dwell. 

 

My solution is when I have the dwell close, I tweak the points arm with a pair of needle nose plyers to get the gap/dwell correct.  Much easier than back and forth with the lock nut.  

 

Similarly I saw a guy with a screen door turn buckle graphed into his timing rod that moves the distributor. He can adjust his base timing while running and lock it down using a timing light perfect. I always think of him when I’m on my 8th adjustment of the distributor by the manual method and my timing light. 

 

Edited April 20, 2018 by Brian_Heil (see edit history)

[Hubert_25-25]

The Buick manual says .020 for the point gap.  I was looking up Dwell for 6 cylinder cars of the 60's with dwell and point gap in the same chart.  I had .020 as 39 degrees dwell.   Is this what you would suggest Ron uses for setting his points?   

[Bleach]

I would not suggest using the same dwell as a 60's car. I doubt the distributor cam of the 25 Buick has the same profile as "modern" distributors. Remember, dwell measure the time the points are closed.

[Brian_Heil]

I respectfully disagree. 

 

Dwell is, well, dwell.  The amount of time a set of points are closed and the coil can build a field you then collapse with their opening.  Our 1920s coil and points are nearly identical to a 1960s coil and points.

 

Correct dwell angle is all the more important on an older engine where the rubbing block of the points is worn or the lobes on the distributor cam are worn, you still want the dwell angle to be correct and the 'correct' point gap may no longer equate to a correct dwell angle.  Correct dwell angle for a 6 cylinder is 32 degrees.  Set it as close to that with the meter as you can and pay no attention to what the gap is.

 

Always set dwell first, before adjusting the timing since changing the dwell can affect timing but not the inverse.

Edited April 21, 2018 by Brian_Heil (see edit history)

[carmover]

Well guys I have found the problem.It wouldn't start this morning and I took the float bowl cover off and the float was all the way down with no fuel in the bowl.I put 5 gallons of non ethanol fuel in the tank and it started right up and I adjusted the carb and had it running like a song and idling and not hesitating when I opened up the throttle it ran for about 5 minutes perfectly and then started to backfire and running rough and finally it shut down completely.I looked in the bowl and the float was back down again with fuel barely trickling in.It very well might be a clogged filter.I removed the fuel cap and it was not the problem and I made sure the vent hole is open.I am going to put 5 more gallons of fuel in and change the filter.But I am sure that it was running beautifully while it had fuel in the bowl so I think this is going to straighten it out.     Ronnie

[Brian_Heil]

There is a fine wire strainer in the bottom of the Marvel at the banjo inlet and one also at the bottom of the vacuum tank/pump outlet.  Both can plug.

 

I've never had a reason to pull my pipe out of the tank to know if there is one there.  Anyone know?

[Hubert_25-25]

There is also a screen on the suction inlet of the fuel line.  Photos of how to make one yourself courtesy of Fred Rawlings

[Morgan Wright]

1 hour ago, Brian_Heil said:

There is a fine wire strainer in the bottom of the Marvel at the banjo inlet and one also at the bottom of the vacuum tank/pump outlet.  Both can plug.

 

I've never had a reason to pull my pipe out of the tank to know if there is one there.  Anyone know?

 

I don't know, but there's a small screen at the bottom of the carb bowl, at the outlet where the gas leaves the bowl and goes into the adjustment nut.

 

That's for the 1918 carb anyway. But that would make the carb bowl flood rather than empty, if that screen was was clogged.

Edited April 20, 2018 by Morgan Wright (see edit history)

[Brian_Heil]

Thanks Hugh. 

 

I figured there was one in there just like that. 

[sligermachine]

10 hours ago, Brian_Heil said:

.  Anyone know?

I have that part  yes it has a fine filter at the end of the pick up . at least with the one that has the 2 copper gasket's that threads in to top of tank .  

[carmover]

What I have found out so far is the gas is bubbling in the carb bowl and eventually fills up and shuts off and it will run at idle about ten minutes before it starts acting up.If I race the motor up it quickly runs all of the gas out of the bowl.I checked the needle and seat and cleaned the strainer under the float bowl and removed the fuel line from the carb to the regulator and blew it out.I put a can under the output of the regulator and it is giving intermittent pulses of fuel which is more air than fuel.I removed the regulator and cleaned and tested it and put a can under the fuel line from the pump to regulator and it is doing it there too. I also cleaned the pickup tube and the steel line to pump.My diagnosis is either a clogged pump or a bad pump I also changed the filter from the tank to the pump.I am going to pull the pump tomorrow and test it .There is no way to clean it because it is a sealed unit.

[Terry Wiegand]

Ronnie,

I'm sure that you know this, but, I'll mention it anyway.  Make sure that the vent hole in the gasoline tank cap is not clogged shut.  If that hole gets clogged up it causes all sorts of problems.

 

Terry Wiegand

South Hutchinson, Kansas

[carmover]

14 hours ago, Terry Wiegand said:

Ronnie,

I'm sure that you know this, but, I'll mention it anyway.  Make sure that the vent hole in the gasoline tank cap is not clogged shut.  If that hole gets clogged up it causes all sorts of problems.

 

Terry Wiegand

South Hutchinson, Kansas

Thanks Terry, I have already checked the cap and blew it out with compressed air and have traced the problem to the pump.It is just sending fuel at a pulse and not a steady stream.I have blown out all of the lines and installed a brand new filter between the tank and pump.I have also cleaned and tested the regulator.I have squirted fuel directly into the float bowl and the engine is running perfectly.