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A25c won't accelerate

thepumpguysc

Senior Member
Joined
Mar 18, 2010
Messages
7,518
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Sunny South Carolina
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Master Inj.Pump rebuilder
The timing off-set is built into the pump.. SO..
when the PUMP POINTER is centered in the window.. the ENGINE will be at TDC..
The aneroid does have a star wheel but the access is under the TOP cover or thru a SIDE cover..
Those engines are always under powered & I always turned them up 10% AFTER I got done TURNING THEM UP to spec..
They were like "race cars" when they gottm back.. Lol
 

Dakotab19

Active Member
Joined
Jun 9, 2019
Messages
43
Location
Michigan
The timing off-set is built into the pump.. SO..
when the PUMP POINTER is centered in the window.. the ENGINE will be at TDC..
The aneroid does have a star wheel but the access is under the TOP cover or thru a SIDE cover..
Those engines are always under powered & I always turned them up 10% AFTER I got done TURNING THEM UP to spec..
They were like "race cars" when they gottm back.. Lol
When you say pumps pointer where is that on the front of the intermediate shaft going to the pump or through the hex plug on the side of the pump, or am I just missing it completely? 15602918866297092390616357743371.jpg
 

thepumpguysc

Senior Member
Joined
Mar 18, 2010
Messages
7,518
Location
Sunny South Carolina
Occupation
Master Inj.Pump rebuilder
Its that 8mm plug below & to the right of the return line.. below the shut-off lever.
Its gonna be TIGHT.. rap it a couple times w/ a hammer & brass drift 1st.
How are the rpm's?? almost every one I've worked on is way low, on max no-load rpm's.. {& fuel}
 

Dakotab19

Active Member
Joined
Jun 9, 2019
Messages
43
Location
Michigan
Its that 8mm plug below & to the right of the return line.. below the shut-off lever.
Its gonna be TIGHT.. rap it a couple times w/ a hammer & brass drift 1st.
How are the rpm's?? almost every one I've worked on is way low, on max no-load rpm's.. {& fuel}
The rpms seem to reach full throttle (around 2500).
 

Dakotab19

Active Member
Joined
Jun 9, 2019
Messages
43
Location
Michigan
Its that 8mm plug below & to the right of the return line.. below the shut-off lever.
Its gonna be TIGHT.. rap it a couple times w/ a hammer & brass drift 1st.
How are the rpm's?? almost every one I've worked on is way low, on max no-load rpm's.. {& fuel}
Is there supposed to be oil in this section of the pump?
 

funwithfuel

Senior Member
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Mar 7, 2017
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5,576
Location
Will county Illinois
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Mechanic
well you're really supposed to have an AB light. its a tool you screw in in place of the plug and has two sensor probes that wait to "feel" the pointer coming by. When both A&B light up you are dead nuts on. In the interest of down n dirty you could just watch for it with a mirror and light.
 

Dakotab19

Active Member
Joined
Jun 9, 2019
Messages
43
Location
Michigan
well you're really supposed to have an AB light. its a tool you screw in in place of the plug and has two sensor probes that wait to "feel" the pointer coming by. When both A&B light up you are dead nuts on. In the interest of down n dirty you could just watch for it with a mirror and light.
What will the pointer look like when it comes by?
 

Dakotab19

Active Member
Joined
Jun 9, 2019
Messages
43
Location
Michigan
Is there a specific spot to bar the engine over with or are you just supposed to use the front of the crank?
 

funwithfuel

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Mar 7, 2017
Messages
5,576
Location
Will county Illinois
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Mechanic
On the exhaust side of the answer in the bell housing front face there should be a 10 plug with I believe a 22 or 24 mm recessed hex . One of those is in line with the edge of the fly wheel with an engine turning tool or pinion you can turn the engine over easily from their otherwise you are stuck trying to turn it from the front of the crank damper. Some of the older machines even had a whole then aligned with the crank bolt so that you could put a long extension in there and turn it from outside the frame
 

thepumpguysc

Senior Member
Joined
Mar 18, 2010
Messages
7,518
Location
Sunny South Carolina
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Master Inj.Pump rebuilder
Yup, special turning tool from access plug in flywheel hsg.
OR.. crank
IF U WANNA KNOW when your GETTING CLOSE, remove the hex head plug up towards the drive on the side of injection pump{12mm?}.. When it STARTS TO RISE, your on #1 compression stroke & start looking in the timing hole for the pointer..
 

funwithfuel

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Mar 7, 2017
Messages
5,576
Location
Will county Illinois
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Mechanic
Timing is set at 8 degree s which is what's specified on the valve cover.

OK now you've learned something valuable and you verified that your timing is correct . next up is put everything back together let's fire it up and see will kind of boost your building. Find A pipe plug or nipple or something between the intake manifold and the turbocharger were you can gauge boost pressure while you throttle up. It would really be nice if you could put a 100 pound gauge on your fuel supply system after the lift pump also to verify that you have adequate fuel pressure to your injection pump.
 
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