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View Full Version : Craftsman w/ Kohler Engine 25HPV-Twin


vtaylor12
Jul 15, 2008, 08:46 AM
Ok - sooo frustrated here!!

I was mowing a couple of weeks ago and my mower just quit and would not restart!

The thing on top (the oil cooler I think) would kind of spin but hang up and not kick in and start. We have looked at several things on it... we tested the starter today.

Well I have been told look into the valves... they may need adjustment... I have been looking at my manual this morning and sure enough it says " will not start - engine valves out of adjustment'

So I have been searching to find out how to adjust them - but not finding a good answer on just how to do it... my manual shows the specs to be -


Valve, exhaust (std.) (2)
Valve, exhaust (.25) (2)
Valve, intake (std.) (2)
Valve, intake (.25) (2)


Does that mean anything to anyone?

Thanks Vanessa

KISS
Jul 15, 2008, 11:38 AM
In a 4-stroke engine the piston is at the base of the spark plug 4x in a cycle.

In 2 of those times, both valves are closed.
In the other 2 only one is open.

You have intake, compression, power, and exhaust.

I'll leave it to the reader to determine the sequence.

When you adjust the valves, the piston should be at TDC (Top Dead Center) + 1/4"

EDIT: Modified based on MM's additional info

MOWERMAN2468
Jul 15, 2008, 07:54 PM
Kiss, on a briggs the piston is to be at TDC plus one quarter of an inch. If you were mowing and it just quit and you are looking at the valves, I would think it may be a pushrod off, or a valve bent or stuck.

KISS
Jul 15, 2008, 11:51 PM
Well, looks like your right. With a little searching found these specs:

Valve Specifications--Briggs and Stratton (http://www.small-engines.com/bsvalve.html)

vtaylor12
Jul 16, 2008, 06:14 AM
Ok we adjusted the valves last night and still not starting!

When the spark plugs are out the oil cooler spins faster when we put the plugs back in it gets real sluggish?

So... do you think that maybe even though we tested the starter (we tested it off the mower) that it could still be the problem? With a load on it maybe it just isn't getting the job done?

Any suggestions at this point will be grateful!

Vanessa

KISS
Jul 16, 2008, 08:12 AM
Actually before trying major troubleshooting, you should:

1. Remove the air cleaner element. (this makes sure you have air)
2. Hold the spark plug against the frame of the mower with an insulated object and check for spark.
3. Insert the plug and try to start the engine to see if the plug is wet. This checks for fuel.

Having these things are required, but if you have them the engine still may not start.