2 M25XP Starting questions

[Stfitts]

Hi All,
I went out to start her up for the first time this season today and experienced a no start. I didn't feel that the glow plugs were getting hot enough, so I'm hoping thats my issue. As I don't know the age of the plugs, I've ordered new ones and going to do the Solenoid mod (found https://www.c34.org/wiki/index.php?title=Faster%2C_More_Efficient_Glow_Plug_Heating_with_a_Solenoid. However, I feel like I've seen conflicting information.

From a wiring prospective, should I be connecting to the Starter or the Starting Battery positive post? I've seen BOTH ways mentioned.

ALSO

Should the "knurl" bleed screw be full open (counter clockwise/Fuel pump clicking constantly) OR should it be fully closed (tight clockwise/slow clicks) for normal operations? When bleeding the engine, should the pump clicks slow down with full counterclockwise?

Also, on occasion when starting, I would get a single click, other times she would turn over just fine (I plan to go back and clean connectors, ensure everything is crimped correctly/not corroded). Any other thoughts on that outside of what I've mentioned?

Thanks, everyone!

[Gregory M]

Also, make sure that shutdown T bar is pushed down fully, I was scratching my head for hours, why engine doesn't start....lesson learned.

[Jim Fitch]

Also remember if you let the engine turn over for more than 30 seconds or so you can be pumping raw water into the engine via the muffler system.  If you crank for a while you have to drain the muffler or you'll have really big problems.  There should be a warning about this on your start panel.

Jim

[Ron Hill]

Stf : When asking about "not starting" identify engine cranks , but will not start!!  I assume that the your engine turns over (cranks)??  Sounds to me like a fuel problem!  Also check your Racor filter bowel for WATER!!

Not too sure about your wire question as the addition of a solenoid has nothing to do with the starter or starting battery.  Follow Capt Als instructions!!

I always keep my bleed valve cracked at about 1/4 turn ON (clockwise) so I have a "self bleeding" fuel system.

A few thoughts

[Stfitts]

Also, make sure that shutdown T bar is pushed down fully, I was scratching my head for hours, why engine doesn't start....lesson learned.

Great tip. While troubleshooting, I ensured the handle was in the correct position and confirmed the linkage was returning fully as well.

Also remember if you let the engine turn over for more than 30 seconds or so you can be pumping raw water into the engine via the muffler system.  If you crank for a while you have to drain the muffler or you'll have really big problems. 

I will double check this, however we didn't crank on her too long, was afraid to kill the battery. I will check the muffler when I get back tot he boat this weekend before moving forward though!

Stf : When asking about "not starting" identify engine cranks , but will not start!!  I assume that the your engine turns over (cranks)??  Sounds to me like a fuel problem!  Also check your Racor filter bowel for WATER!!

Not too sure about your wire question as the addition of a solenoid has nothing to do with the starter or starting battery.  Follow Capt Als instructions!!

I always keep my bleed valve cracked at about 1/4 turn ON so I have a "self bleeding" fuel system.

The solenoid mod ensures efficient glow plug performance, and seeing as how I didn't feel a ton of heat coming from them, I might as well do the mod.

Thanks for the information on the bleed screw!

[waughoo]

The glo plug mod only shortens the length of glo time needed to start and reduces the amperage going through the switch at the panel.  If it worked before and not now AND you don't think there is heat at the glo plugs, you might want to do some troubleshooting before doing the mod. 

[Ron Hill]

Stf & Guys : If you wind up having to crank the engine over a number of times - don't screw with the muffler drain just turn OFF the raw water thru hull and crank.  If the engine starts you have more than enough time to turn ON the RW thru hull!!

A thought

[High Current]

Should the "knurl" bleed screw be full open (counter clockwise/Fuel pump clicking constantly) OR should it be fully closed (tight clockwise/slow clicks) for normal operations? When bleeding the engine, should the pump clicks slow down with full counterclockwise?

Counter clockwise to bleed, clockwise for normal.  The pump "clicks" to pump fuel when there's low back pressure; if you open the valve you remove that pressure allowing it to bleed.  Normally the only fuel that flows is from the injectors so you have a slow click.

Any other thoughts on that outside of what I've mentioned?

On my new-to-me C34 of unknown provenance, the engine cranked but did not run...until I realized the glow plugs were not getting power and replaced the ignition switch.  Watch your voltmeter when you press the glow plug button; you should see the battery voltage sag a bit.

I will double check this, however we didn't crank on her too long, was afraid to kill the battery.  I will check the muffler when I get back tot he boat this weekend before moving forward though!

DO worry about the water buildup in the muffler.  Also overheating the starter motor.  Battery not so much.  Because I'm an electrical engineer and a data geek I measured the cranking current on mine recently and it was about 160A (also M25XP).  A full minute of cranking therefore uses <3% of a 100Ah battery (160A * 1 minute / (60 minutes /hr) = 2.67Ah).

[Ron Hill]

Guys : The glow plug Mod drastically decreases the time you need to engage the glow plugs!! Like to 5 seconds  You are using #8 wire (rather than #10) and the glow plug current is not going from the battery to the engine panel and then back to the glow plugs!. Now the glow plug switch/button only opens the solenoid so the current can go from the starter solenoid connection direct to the glow plugs!!   

A few thoughts