So I have a "new to me" '25 coupe. New wheels, brakes, fluids, radiator, etc... Did the adjustments on free neutral, which seem to be working well.
My problem is that while the car does well on flat ground and downhill, of course, it lacks power on any type of incline, even slight. 1st gear works ok until the incline gets speed...then it seems to start bogging down. 2nd gear has trouble getting going even on slight inclines, but seems to really drive fine on flat ground or downhill (picks up speed and chugs right along). I've gone through the threads on shifting and tried various engine speeds during shifting on very slight inclines.
Have tuned/tweeked Carb needle, rebuilt carb, gone through timing set twice (top dead center). Spark starts 2 clicks down from top and seems that timer rotates about as far as possible when down all the way, so timer rod seems to be bent correctly.
Any help or ideas appreciated Thanks!
Do not use a 1/4" in-line fuel filter. I removed one from a friends car that was having problems like you have described. After removing the in-line fuel filter.....problem went away. Also, make sure the screen in the tank sediment bulb is clear.
Are you running on battery or mag?
I can see the full advance running on battery but if you're TRYING to run with full advance while on magneto there's your answer.
My '19 touring needs to run full advance on battery but only 1/3 advance on magneto.
Your coupe isn't going to be a speed demon as there is lot more steel to carry around with a coupe. (I had a '20 coupe)
Make sure the tires are fully aired up too.
No fuel filter....
Start on battery then switch over to Mag before driving...
Tires new and full....
Car doesn't like full advance either....runs smoothest at halfway, even trying to chug uphill.
I'm not looking for speed, but it seems very labored on the shift on the slightest incline at all....can't pick up any torque at all and go....throttle or timing adjustment doesn't seem to affect it
1- With car running at idle and already warm, point the 'straw' of carb cleaner at the manifold gland and quick burst of spray...engine picks up speed, you have leak! Leaks cause weird things! No leak? Go to #2....
2- Make sure the sediment bulb screen is not slimed. Then make sure gas tank has over 2" of gas in it. Open the needle valve another half turn over where you 'think' it should be and try again. Report back
If the above advice doesn't get any results take a compression test and see what the condition of the engine really is.
If the compression is 50 psi or more, check the coils next.
Original coils, even with new points almost always need a new capacitor and often provide random misfires that can only be seen with a Hand Crank Coil Tester or a StroboSpark Coil tester, which also identifies the bad capacitor problem.
Your symptoms sound like what occurred to me this past week during our regional tour. It was the second day and the hills in North Georgia were the downfall. I made it back to the garage (our enclosed trailer) and first cleaned the soot off the plugs. I then took the timer apart (New Day) and found a groove where the brush touched the timer cover between the contacts. Replaced the timer and brush and had smooth performance for the rest of the tour. I still prefer the New Day.
Well...I may have the problem.
Did a compression check. I don't have a reducer from 1/2" plug to a modern compression gauge, but I used some hi-pressure hose and clamps to get from 1/2"-hose connection to the gauge. (no leaks, gauge stayed at same reading and didn't go down).
All plugs out, throttle and choke wide open. Compression came back at 26. Granted, I'm at 7400' above sea level in Colorado, but that still seems mighty low....
Question, it runs good at idle and on flat ground seems to do fine. Would 26 be enough for this or is my reading off? I want to make sure before going after the valves and rings. Thanks
A compression reading of 26psi is quite low. Did you get the exact same reading on all four cylinders?
How much extra hose did your lashup have? That will affect the reading.
Next step is to put cyl at TDC, then apply about 10-15 psi from air compressor and listen for leak at intake, exhaust and oil filler. Be cautious, as a little off TDC will spin the engine.
Readings were within 2-3 psi on each...
Used 6 in of thick 3/8 hose
The most accurate area of mechanical gauges is the center 3rd section.
New compression gauges mostly have Zero to 300 psi dials. That makes 50 psi the center of the lowest 1/3rd area.
Tractor Supply sells a Zero to 100 psi gauge for about $25. The gauge is larger and very easy to read.
Tractor Supply Gauge vs Typical Gauge
The best Model T compression gauge is made by taking a modern set, removing the Zero to 300 psi gauge, replacing it with the Zero to 100 psi gauge and putting a 14 mm to 1/2 inch pipe thread adapter on the other end of the hose.
That's great James! We have a Tractor Supply close...I'll try that first. I went by Home Depot looking for that thread adaptor but to no avail....
The only place that you'll find a 14 mm to 1/2 inch pipe thread adapter is at one of the T parts vendors, Like Mac's or Snyders or Langs, etc.
Sacrifice a 14 mm spark plug and weld a 1/2" pipe nipple or reducer bushing to it.
In your initial posting you mention "timing set twice (top dead center)". Your spark should be set to just occur at 15° after TDC incase that's not how you set it.
I've ordered the adapter and will make sure of my compression reading. While waiting on Snyders, I'll do the air leak test on each cylinder and check for valve/ring leaks.
Thanks Garnet....meant that I double checked my work and set the timing two different times to make sure I had found correct "top dead center"...timing is set after
Will update on compression and air test...thanks all!
Rowland, how is the rear end set up because you might have the wrong ring gear I have a 40 tooth ring gear and an 11 tooth drive shaft gear in my car and it zips up hills . If not you might have a transmission problem
Not sure of the rear end setup yet....just got the car 3-4 months ago and have been working my way down the priority list. I'll add this to the check list. I'm hoping to check for valve and ring leaks tomorrow.
You can find the gear ratio by placing the car on a flat surface such as a level concrete slab. Put the parking lever all the way forward so the car is in high gear. move the car until one valve stem is at the bottom. Leave the ignition switch off. Then move the car forward using the hand crank. Make full rotations of the crank. Count how many turns of the crank it takes to move the rear wheel one complete turn. The standard gear ratio is 3.6 to one, so it would take just over 3 1/2 turns of the hand crank to make one turn of the rear wheel. One of the aftermarket gear ratios is 3 to one. That would take 3 turns of the hand crank to one of the rear axle. That ratio works pretty well on flat ground, but is too high for a Model T. It will work with an auxiliary transmission such as a warford or Ruckstel, which has an intermediate range between high and low, but it is too high for a standard Model T.