M25 Correct engine stopping procedure

[Gary]

I have always used the decompression lever to stop our M 25 Universal.  That is until reading the recent "Dead Battery" threads.  There the Torrenson Marine URL added by Stu indicates the correct proceedure is to use the throttle, all the way back, to what is called the "spring release position".  The Torrenson URL says that using the decompression lever for stopping the emgine will result in damage to the exhaust valves.  I do not think my throttle has this feature as in the all the way back position the engine is at idle.  No spring back position either.

We have a 1986 Universal.  What are others doing as a way to stop engine?

Thanks!

[Jeff Kaplan]

gary, we have the same engine and the boats came off the line at the same time. i have an  engine stop cable which is pulled to stop the engine, then shut off the key. it's been this way for 20 years with no problems and i expect it to be this way till the end. great sailing  season so far here in the boston area, how about a 100 miles north?   jeff

[Mike Vaccaro]

Gary,

The M-25 is/should be equipped with an engine-stop lever.  This is depicted at:

http://www.marinedieseldirect.com/catalogs/catalog_group.php?owner=mdd&page_ident=200142-21&model=M-25%20/%20M-25XP&manufacturer=Universal&title=Engine%20Stop%20Lever%20Group&quant_position=&catalog=200142&printparts=200142&printservice=200151&printoperators=200157&comment1=


This stop lever is connected to a T-handle on the engine control panel of our 1988, Hull 563.  We have an M-25XPA engine. 

Use of the decompression lever to stop the engine should be avoided because it can damage the exhaust valves.  It's fine in an emergency, i.e., run-away, fire, etc. but should not be used on a regular basis. 

The decompression lever is also handy when you are doing maintenance.  If maintenance requires the engine to be turned or you are turning the crank, it can be safety wired to the open position to prevent the engine from unintended firing.

Odds are if you've been doing this for a while and the engine is running fine, you're O.K. (it's just a simple tractor motor, after all!).

Cheers,

Mike 


 

[Ken Juul]

I think there is some confusion over names.  The engine stop T handle on the engine control panel shuts off the fuel  at the Throttle & Governer Assembly to stop the engine.   The Decompression lever releases or prevents compression by holding the exhaust valves open (I think).  The decompression lever can only be accessed by opening the engine compartment.

[Stu Jackson]

Here's another link to Mike's referenced link to the engine page (which didn't seem to work for me): http://www.marinedieseldirect.com/universal/200157/universal-owners-manual-stopping-engine.html

Item 4 explains two different engine group models. Read the entire paragraph (item 4). The M25 uses the stop lever, which is at the cockpit panel. 

The decompression lever is on the engine, as shown in the picture of the engine from that website that I suggested reviewing in the earlier dead battery post, reply #14 at: http://c34.org/bbs/index.php?topic=3814.0.

Gary, just curious: How'd you stop the engine without having to remove the steps and covers all the time when using the decompression lever?  Or didn't you?  

Think you'll find it lots easier this way!  

Perhaps Ken is right, and we're talking the same thing, but let's find out, for Gary's sake.

[Mike Vaccaro]

Thanks Stu...see what happens when a fighter pilot tries to use a computer?

Cheers,

Vac

[Jeff Kaplan]

gary, i should have noted in my reply, that the engine shut off cable does not go to the decom. lever but to ,as ken stated, the throttle & gov. assembly. as asked, how do you stop the engine without having to remove the ladder and engine cover platform? i thought all the m25s and xps were stopped by pulling up on the engine shutoff cable...jeff

[Gary]

Thanks everyone for the help and the clarifications.  I have been using the T handle at the engine control panel for engine stop.  My mistake was calling the T Handle a decompression lever.  I will find the decompression lever on the engine and learn how to use it for a runaway diesel situation. 

My gratitude to everyone's patience and knowledge...this site has been terrific!

The sailing was terrific today... easterlies from the cool Maine Atlantic 10-15 kts.  And blue skies.

Thank you, Ken, Stu, Jeff, and Mike....just terrific help !!

[Ron Hill]

Guys : All diesels are stopped by fuel starvation!!

I believe that the decompression lever opens all valves. 
The reason for the decompression lever (as I understand it) is to assist when battery voltage is low.  The procedure is to heat the glow plugs, open the decompression lever, engage the starter which will easily spin the crankshaft easily with NO compression and then close the lever.  Closing the lever will cause the compression and centrifical force of the fly wheel helps continue the spin and the engine starts.

I've had some friends use that procedure and it starts the engine (I've never needed that).