kohler 775 horizontal starter issue

[plotthound]

sometimes when I try to start my 775 kohler the starter will not turn the engine over.its like the engine is on compression stroke and the starter cant quite do its job.when I release the key and try again it starts right up.normally this would not be a huge concern. but the engine is in my argo and when im 20 miles from my truck it gets me a little anxious.anyone here run into this issue?

thanks

[okie]

how long has it been since the valves were adjusted?



Travis

[bgsengine]

First, do a voltage drop test on the ground side - any poor connection anywhere from battery to starter and back to battery, you will have a voltage drop that can cause that. Also check compression - if it is high (180+ PSI) then you likely have a worn camshaft but if not, I'd be looking at electrical issues first - we always run a voltage drop test on units that come in with that sort of complaint - it is faster and easier than compression testing. and quickly eliminates or confirms an electrical issue

[plotthound]

valves have never been adjusted,engine has fairly low hours but it may be due.how does one do a voltage drop test bgsengine?

thanks

[bgsengine]

valves have never been adjusted,engine has fairly low hours but it may be due.how does one do a voltage drop test bgsengine?

thanks

DVOM - test meter / fluke meter - set on DC volts, red lead to B+ post, black lead to Battery cable terminal for that post disconnect spark plug wires, turn key to crank, should be no more than 0.1v measured there if it is more you have a bad battery terminal to battery post connection - move the black lead to the solenoid post , battery side, repeat test - keep repeating the test all the way to the starter terminal where battery cable connects to it - every test point should be less than 0.2 volt when engine is cranking - if you get a higher reading there's your voltage drop. Then connect negative cable to starter case ground and move red test lead to B- post and voltage drop test the ground side - again should read less than 0.2 volts - if all tests pass then your starter electrical system is good. voltage drop testing is similar to resistance/continuity test but with a full amperage load and measuring the voltage potential at any given point of the circuit.

[plotthound]

thanks again bgsengine.that gives me a great start on figuring this out.

[Arkie]

Way out in the boonies and engine crank hung on compressio0n stroke and click, click click.

Been their on ATV's by myself (no cell phone or cell phone signal) and sure dread the thought of a long hike.
To get er going see if the engine has a compression release mechanism. If so activate the compression release and try to start. compression release will reduce the load on the electric start system.
If the rig has a manual rope crank they usually also have a MANUAL Compression release, activate the compression release pull the rope and hit the electric start at same time the engine is turning over. I've done this to get out of the woods.

Sometimes if you can't quite figure it out with voltmeter voltage tests, trying jumping to your eq with jumper cables carefully from a vehicle, when you testing the rig, just to see if the additional battery turns it over good. If so suspect a bad battery.
I've seen batteries just weak enough especially on ATV eq that the starter would appear bad and the jumper from a vec would make it go so as to determine if battery is little weak. (I've had guys bring me $150 starters from ATV's to bench test and I would not even bother doing such if the engine was cranking slow like yours, because too many lesser priced things are usually what's bad. I tell them to bring me the machine or at least replace the battery if they have not already done so especially if the bat is over year old. Also I advise them that several automotive parts places and even ole Harbor Freight sells battery testers that apply around 100 amp crank load to a battery so as to test the battery (good/Bad scale) under load that will ID a battery that is just a little bit weak, USUALLY. (these testers need to be connected directly to the battery terminals of the battery under test instead of the battery cables, unless you are using the load tester to test the cable connections. Also keep in mind that when jumping to a battery from another vec battery that you are bypassing the possibility of a bad battery cable connection in the suspect vec and also that a engine that is at operating temp (not cold) will take more crank amps to get thru the compression stroke.

Also sometimes when you are in the boonies or caught out without an electrical tester and crank is weak or no go you can carefully find a bad connection by carefully feeling of the terminal connections right after trying to crank. (using fingers to feel of connections) a bad connection will produce heat and sometimes hot enough to fry meat).
I'm a electrician and electronics tech and sometimes your crank/compression hang issue is one of the harder ones to pin down to only one thing being bad and even harder if its a combo of more than thing. (weak battery and valves out of adjustment for example)

[KE4AVB]

Might also check the starter commutator rings for glazing which would produce high resistance for the carbon brushes. I have had automobile alternators to appear to be bad when only commutator rings were glazed over. Just thinking of possibles.

BTW is this a Aegis LH775 as like to look at parts and service manuals to what the setup is? I think one of shift starters that may need relay kit added like the John Deere did to overcome a voltage drop on the solenoid engage power line on some their Kohler setups. The solenoid would only partially engage causing starting problems.

[plotthound]

thanks for all the advice guys.i was gonna try to give it a boost with my power pack but am afraid of frying the ECU.at least now I have lots of other things to try.

cheers

[38racing]

section 17.35 of this manual has good stuff on poor cranking and voltage drop

Clickable Link
http://web.ncf.ca/da229/smallengine/mtd-769-01415_electrical-2.pdf