Late model starter motor help and compression test
Created by: 6464s
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I would be looking carefully at the electrical connections ...especially the earth route back to the battery.
From my recollection, 64S has been around for a while so I presume he would already have performed a few tests/pre-operation precautions as he was asking about checking compression????
He did mention the engine is in a cradle... So, is it a new build or what. One might hope that it has been recently lubed (assembly lube on rings and bearings if new) or some oil down the bores (through the plughole) along with new oil if an older engine coming out of hibernation. .... And, has it been rolled over by hand a few times to ensure nothing is binding up???
Depending on how its attached to the cradle it may be easy to remove the wok and check the starter gear/flywheel engagement. Its not that easy to check the operation of the bendix gear without operating the starter. If you do remove the starter from the engine you can at least spin the gear and check that it slides down the shaft freely (and bounces back).
If the engine turns (easily) by hand ..... and the starter spins ... and all the electrical connections are OK then the starter should spin the engine and gearbox whether/what ever gear its in (with the engine in a cradle the drive shafts will not be attached??)
Removing the starter and checking it operates stand alone with the starter switch is a good idea (not forgetting the (heavy duty) connection between the starter case and battery earth.) ...
Cheers, Ian
From my recollection, 64S has been around for a while so I presume he would already have performed a few tests/pre-operation precautions as he was asking about checking compression????
He did mention the engine is in a cradle... So, is it a new build or what. One might hope that it has been recently lubed (assembly lube on rings and bearings if new) or some oil down the bores (through the plughole) along with new oil if an older engine coming out of hibernation. .... And, has it been rolled over by hand a few times to ensure nothing is binding up???
Depending on how its attached to the cradle it may be easy to remove the wok and check the starter gear/flywheel engagement. Its not that easy to check the operation of the bendix gear without operating the starter. If you do remove the starter from the engine you can at least spin the gear and check that it slides down the shaft freely (and bounces back).
If the engine turns (easily) by hand ..... and the starter spins ... and all the electrical connections are OK then the starter should spin the engine and gearbox whether/what ever gear its in (with the engine in a cradle the drive shafts will not be attached??)
Removing the starter and checking it operates stand alone with the starter switch is a good idea (not forgetting the (heavy duty) connection between the starter case and battery earth.) ...
Cheers, Ian
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A clicking starter could be from several causes dead battery, stuck Bendix drive, stuck or defective solenoid. If the starter gear or flywheel ring gear are worn or damaged, the gear may not be engaging properly.
First, check that the battery is good and has a full charge. or bad windings in the stater motor itself.
Did the starter come with the motor, or did you add it? Is it the right one for the engine - pre-engaged or not?
I would make sure the transmission is in neutral (assuming it is a Mini lump). remove the spark plugs and try wrenching the engine over to see if it is seized. If it isn't, remove the starter and test it with the battery and cables. The Bendix drive (depending on the type of starter) should shift the gear on the shaft as if to engage the ring gear and then the gear should spin... or something similar.
If the starter checks out OK, check the ring gear on the flywheel.
First, check that the battery is good and has a full charge. or bad windings in the stater motor itself.
Did the starter come with the motor, or did you add it? Is it the right one for the engine - pre-engaged or not?
I would make sure the transmission is in neutral (assuming it is a Mini lump). remove the spark plugs and try wrenching the engine over to see if it is seized. If it isn't, remove the starter and test it with the battery and cables. The Bendix drive (depending on the type of starter) should shift the gear on the shaft as if to engage the ring gear and then the gear should spin... or something similar.
If the starter checks out OK, check the ring gear on the flywheel.
.
"Hang on a minute lads....I've got a great idea."
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Tried last evening, motor did not turn over (bad sign), just clicked.
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Quote:
Originally Posted by 1963SV3
"..I'm not sure if that is a compliment or a "shot". ??..."
Definitely a compliment.
Cheers, Ian
Definitely a compliment.
Cheers, Ian
He probably also has a good idea it'd be you, as there are so few of the original crew left posting these days......most have vanished
for one reason or another.
Even though I own 2 Binis, I would much rather read about true Minis any day of the week.
Seems like 75% of the posters these days are the "one and done" crowd asking about Binis.
A sign of the time perhaps.
~ 30 minutes in a Mini is more therapeutic than 3 sessions @ the shrink. ~
Mike NB, Canada
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Dan, I have not gotten to the actual cranking because I misplaced my compression tester ( lost it ) and am waiting on a new one. I did do the switch and will be ready to go once I get the CT. Thanks for the guidance. Jim
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6464s
How did you make out? Did the starter work? How was the compression test?
How did you make out? Did the starter work? How was the compression test?
.
"Hang on a minute lads....I've got a great idea."
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Quote:
Originally Posted by 1963SV3
"..I'm not sure if that is a compliment or a "shot". ??..."
Definitely a compliment.
Cheers, Ian
Definitely a compliment.
Cheers, Ian
As a former architectural specification writer, I learned how to write accurately, logically and clearly. The tricks an "old dog" knows can still be put to use.
Cheers!
.
"Hang on a minute lads....I've got a great idea."
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"..I'm not sure if that is a compliment or a "shot". ??..."
Definitely a compliment.
Cheers, Ian
Definitely a compliment.
Cheers, Ian
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Quote:
Originally Posted by 1963SV3
Dan M will probably be along to provide a comprehensive answer ..... in the meantime.
Cheers, Ian
Cheers, Ian
The on-starter solenoid should have 3 visible terminals - a big fat one the battery cable connects to and two smaller ones. The other fat terminal you would expect to see on a separate solenoid, going to the starter, should be an internal connection in this case.
If it is in a car the big terminal would have the battery cable and a bunch of brown wires going off to various locations.
One of the smaller terminals, probably the one closest to the big one, is the trigger terminal. In a car it would have a brown/red trace wire leading to the starter relay which is controlled by the ignition switch. (On an older car it might be a white/red trace going directly to the ignition switch.)
The starter relay is powered by a brown wire from the hot side of the fuse block. The white/red trace from the ignition switch controls it and it feeds a charge down the brown/red to the solenoid on the starter.
So, you need to connect a switch between the big terminal and the trigger terminal. Once you have the battery connected, spark between the big terminal and the smaller one with a screwdriver. The trigger terminal will spark and cause the starter to jump. Sparking between the big terminal and the other small terminal should not do anything - it is only connected when the solenoid is activated, and it would be the same +12V as the large battery terminal.
In a car. the third terminal would have a white/yellow trace wire - it is the full voltage starting power to a ballasted ignition coil. It supplies 12v during cranking and disconnects when you release the key from the "start" position.
Use jumper cables to connect the battery to the starter and the engine ground. Most people have a pair laying around and they are cheap to buy.
For the trigger wire and switch, use something like #10 stranded wire and a strong momentary switch (push button etc.) that disconnects when you stop pushing. Put alligator clips on the free ends - it will come in handy for other uses. I have a very light version I use for kicking the engine to top-dead-centre to set timing. It get hot if I use it too long!
.
"Hang on a minute lads....I've got a great idea."
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Dan M will probably be along to provide a comprehensive answer ..... in the meantime.
The starter takes a lot of power so... make sure the live feed and earth are similar to the heavy duty cable used for this purpose in the car. Spare welding cable is suitable...
The solenoid is in effect a relay so you need the HD cable runs from battery to solenoid and solenoid to starter. Not sure what you mean by the solenoid "sitting" on the starter ..but, maybe, the solenoid to starter connection is internal???? You also need a heavy duty cable from the engine (use one of the clutch cover bolts - starter earths through the block) to the battery negative (i.e. earth).
Now ... you need something to simulate the starter /ignition switch. Run a "normal" wire from the battery + to a switch to the solenoid. The HD terminals and switch terminal on the solenoid should be "obvious". The switch circuit earths though the solenoid body to the engine block (and to the car body and back to the battery negative (earth wire)) when installed in the car. If the solenoid is attached to the starter case and this is earthed (as noted above) then you should be sweet.
Flick the switch and the starter should crank..
You may need an assistant depending on whether your gauge screws into the plug hole or is just held in place.
Open throttle, crank about 10 revs (you'll hear them). The gauge will wind up (reading increases) and eventually will stabilise. It will still flick as the piston being tested goes through the compression stroke but the reading will max out.
Good luck, run each cylinder measurement a few times until you get consistent readings.....
Cheers, Ian
The starter takes a lot of power so... make sure the live feed and earth are similar to the heavy duty cable used for this purpose in the car. Spare welding cable is suitable...
The solenoid is in effect a relay so you need the HD cable runs from battery to solenoid and solenoid to starter. Not sure what you mean by the solenoid "sitting" on the starter ..but, maybe, the solenoid to starter connection is internal???? You also need a heavy duty cable from the engine (use one of the clutch cover bolts - starter earths through the block) to the battery negative (i.e. earth).
Now ... you need something to simulate the starter /ignition switch. Run a "normal" wire from the battery + to a switch to the solenoid. The HD terminals and switch terminal on the solenoid should be "obvious". The switch circuit earths though the solenoid body to the engine block (and to the car body and back to the battery negative (earth wire)) when installed in the car. If the solenoid is attached to the starter case and this is earthed (as noted above) then you should be sweet.
Flick the switch and the starter should crank..
You may need an assistant depending on whether your gauge screws into the plug hole or is just held in place.
Open throttle, crank about 10 revs (you'll hear them). The gauge will wind up (reading increases) and eventually will stabilise. It will still flick as the piston being tested goes through the compression stroke but the reading will max out.
Good luck, run each cylinder measurement a few times until you get consistent readings.....
Cheers, Ian
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I want to do a compression test. The engine is cradled, starter motor attached to engine. Starter motor is the type with solenoid sitting on it. There are studs coming out the end of the solenoid. How do I get the starter to crank the engine? To which stud do I apply 12 volts to and do I just apply ground to the engine? I don't want to burn out the starter motor. Thanks.
I know that I have to open the intake and take all spark plugs out. How many times do I crank?
I know that I have to open the intake and take all spark plugs out. How many times do I crank?