Universal M20 Head Scrathcher

[Seasic]

Originally Posted by Cpt Mark

No spark. It's a diesel

Understood, I was using spark as a generic term for ignition.

Air
Fuel
Ignition

Glow plugs a relatively easy to check

[Cpt Mark]

Originally Posted by Seasic

Understood, I was using spark as a generic term for ignition.

Air
Fuel
Ignition

Glow plugs a relatively easy to check

Glow plugs are if you have them LOL. I wish I did, living in the PNW with snow they would make starting easier.

The basic's of engine Air, Fuel, Ignition, Timing and starting battery are the same but unlike gas engines, diesels are so much easier and so much more reliable. If you have a good battery and it won't start, it's going to be a fuel related issue.

[SV_Harbinger]

and after a solid rebuild from the engine kill lift in the cockpit all the way,to the front of the block itself still no dice, me thinks its time for new injectors.... let's see where that leads me

[Cpt Mark]

Originally Posted by SV_Harbinger

and after a solid rebuild from the engine kill lift in the cockpit all the way,to the front of the block itself still no dice, me thinks its time for new injectors.... let's see where that leads me

All injectors going bad at the same time? Don't think so. Did you measure battery voltage while cranking?

[SV_Harbinger]

sure did started out at 12.9 before hitting the glow plugs for a minute cranked for 10 sec, 12.8 repeats for another 12.8, and after an extra long glow plug hold and an additional 10 sec of cranking, 12.6

[Cpt Mark]

so the engine turns over normally now? and you disconnected the fuel shut off, pb blastered it and using your fingers it goes back and forth easily ? Did you try tapping gently with a hammer to be sure it's all the way in the run position?

If still no go, how exactly did you bleed the system? Do you have a racor?

[jimbunyard]

I'm still curious why it won't fire with ether. Have you checked to ensure that the compression release hasn't stuck open?

[SV_Harbinger]

I do have a racor, it was one of the first things that I went through, it didn't look like it needed a change but got changed anyway.. . and yes the shut off got completely taken apart PB-ed and moves ever so sweetly by hand, haavent tried tapping it with a hammer yet, because it moves so nicely... I'm getting good rpms from the started, just not firing, although it did sputter a little on the ether today .....

[SV_Harbinger]

and the m20 doesn't have a compression release

[Cpt Mark]

Ok. Have you removed the air filter and squirted WD-40 continuously into the air intake? I like WD-40 better than ether but you need to be cranking while spraying.

I have 1 engine that doesn't like to start and I have to disengage the transmission (push in the button and move throttle forward) and give it more fuel. Think of it like a choke. Give it full throttle but be ready to instantly bring it back to neutral if it fires.

Let us know if this worked

[jimbunyard]

Exactly which M20 do you have? Most of them have a spring that connects the throttle lever to the rack control mechanism, there is also a 'start spring' that hooks into the rack control lever.

Both of these springs are made from fairly fine wire; the end hooks have been known to break, which could leave the pump in a no-fuel mode regardless of throttle position.

[Compass790]

Originally Posted by jimbunyard

I'm still curious why it won't fire with ether. Have you checked to ensure that the compression release hasn't stuck open?

That struck me too Re ether but he said in OP that he did a compression test.

[SV_Harbinger]

it's a 1997 m3-20 when I get back to the boat i can get the serial number off it if that helps...

[ulpilot45]

If the engine has glow plugs remove them crank engine over with the starter and see if you get fuel most out of the holes for the glow plugs if you do the injection pump and nozzles are fine look to spinning speed of starter or compression

[jimbunyard]

If you don't have the M3-20 service manual a copy is here.

https://www.westerbeke.com/technical...hnical_man.pdf

This manual has a very good description of the complete fuel system. The description of the springs and their function referred to previously is on pages 67-69.

You could also just remove the plate that covers the rack and control rod and operate it by hand whilst starting the engine to see it there is a problem with either the springs or the governor mechanism.