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1925 chevrolet starting help


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Hi

im in need of help my 1925 chevy has had the babbits done,the pistons sleeved with new pistons and rings, the engine is now back together using the marks on the gears but we cant get it ro run, fantastic spark, fuel is coming through ok , we have tried changing the timing but nothing works, does anyone have any tips or ideas for me please?

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  • airbrush changed the title to 1925 chevrolet starting help
17 hours ago, JFranklin said:

If you have spark and fuel then you need to check for compression, as well as if the spark gets to the fuel at the correct time. It will run if all these are properly set.

Theres good compression ,fuel and spark the timing has been reset so many times but nothing seems to work. 

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I have been thinking about this today and I must say I have not got up close and personal with a 25 Chev but I have with both 26 and 27 Chev’s. My understanding is that the 25 Chev has a gear driven generator that also has the distributor driven of the the back of it and also the oil pump . So I’m not sure when you say you set the timing of the gears do you mean the valve timing or the ignition timing because if it’s the ignition I’m not sure which gears you are referring to. I know on the 27 Chev they have timing marks on the fly wheel so they are easy to set as long as the fly wheel is installed correctly but the 26 Chev does not have this luxury so it’s the old pull a spark plug out and Check that the points are opening when the piston is on TDC or there abouts. 
As for the valve timing We rebuilt the engine in my 27 a number of years ago and installed new timing gears only to discover that the marks on the gears were incorrect and we had to reset them accordingly. Hopefully this helps a little if I get a chance I think I have a manual for 25 Chev somewhere here I will check it out for pointers

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8 hours ago, Vintageben said:

I have been thinking about this today and I must say I have not got up close and personal with a 25 Chev but I have with both 26 and 27 Chev’s. My understanding is that the 25 Chev has a gear driven generator that also has the distributor driven of the the back of it and also the oil pump . So I’m not sure when you say you set the timing of the gears do you mean the valve timing or the ignition timing because if it’s the ignition I’m not sure which gears you are referring to. I know on the 27 Chev they have timing marks on the fly wheel so they are easy to set as long as the fly wheel is installed correctly but the 26 Chev does not have this luxury so it’s the old pull a spark plug out and Check that the points are opening when the piston is on TDC or there abouts. 
As for the valve timing We rebuilt the engine in my 27 a number of years ago and installed new timing gears only to discover that the marks on the gears were incorrect and we had to reset them accordingly. Hopefully this helps a little if I get a chance I think I have a manual for 25 Chev somewhere here I will check it out for pointers

we think the marks are incorrect we did get it running today but not for long, the engine timing we have set by using the tdc instead of the marks on the gears, we have set the points in the distributor so they open at the correct time and the rotor is at position 1 hopefully we will get it running properly tomorrow. Any help would be appreaciated

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Take out #1 spark plug and insert a straw-

by hand, rotate the engine so that the piston raises the straw to the top of the stroke to assure Top Dead Center,

Check that BOTH valves for #1 cylinder are closed

(no tension on the valves - in other words, both rocker arms are NOT pushing on the valves - easy since you have an open valve train)

there should be the slightest bit of slack between the pushrods and the rocker arms-

If the valves are not closed, try another full rotation to assure that you are at Top Dead Center at the end of the compression stroke-

If this is still not the case , the while ignition timing was set, valve timing may be/is incorrect

Now, with the distributor cap removed, check which way the rotor is pointing,

and if the cap were in place,

is this the position of the wire leading to #1 spark plug? It should be!

And, your firing order should be 1, 3, 4, 2 - as I recall from our '27 Chevy,

so check which way the rotor turns, and double check your wires per the firing order

 

Good Luck, and I have a few 4-cylinder Chevy parts - if needed

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On 9/28/2020 at 3:03 AM, Marty Roth said:

Take out #1 spark plug and insert a straw-

by hand, rotate the engine so that the piston raises the straw to the top of the stroke to assure Top Dead Center,

Check that BOTH valves for #1 cylinder are closed

(no tension on the valves - in other words, both rocker arms are NOT pushing on the valves - easy since you have an open valve train)

there should be the slightest bit of slack between the pushrods and the rocker arms-

If the valves are not closed, try another full rotation to assure that you are at Top Dead Center at the end of the compression stroke-

If this is still not the case , the while ignition timing was set, valve timing may be/is incorrect

Now, with the distributor cap removed, check which way the rotor is pointing,

and if the cap were in place,

is this the position of the wire leading to #1 spark plug? It should be!

And, your firing order should be 1, 3, 4, 2 - as I recall from our '27 Chevy,

so check which way the rotor turns, and double check your wires per the firing order

 

Good Luck, and I have a few 4-cylinder Chevy parts - if needed

Im not sure if its the carb we have had it running now but it wont rev properly and the choke wont work we are going to fit a later carb to test it . What parts do you have?

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  • 2 months later...

I may have one, but it could be RKXO - on something like that -

will check when I get over to the other garage,

also have other 4-cylinder chevy parts

clutch & Pressure plate, etc,

maybe distributor & cap, etc

 

Best to PM me as a reminder-

I don't get on-site as often as I'd like right now

Edited by Marty Roth (see edit history)
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