The Universal M25 is winning the battle

[Quadrille in JB]

The bottom line is; until you have good clean fuel coming out of the injector inlet nuts nothing is going to happen.
With you changing filters and lines at all there’s a very good chance that you have an air leak. You’ve had lots of good advice From the guys on this forum.

[Shaneesprit]

Squirt of WD40 - never tried WD-40 but I would first Use Easy-Start or brake cleaner - don’t over do it, but if It runs on flammable spray ( Easy Start ) at least shows you have compression and May even help the engine bleed it’s own fuel system.

[GordMay]

Greetings, and welcome aboard the CF, jarin.

[skenn_ie]

Originally Posted by donradcliffe

There is a governor, but after I bleed up to the IP I will open the throttle wide and crank until the injector pipes start squirting. They were squirting before, but it might have been water/fuel.

Someone brought a small yacht alongside me a couple of years ago. The 2nd time he started his engine, I listened from my cabin, went out n asked him if his was a single cylinger engine. It wasn't, so I said that it sounded like one. I told him to crack the injector pipes with the engine running. Crack 1, engines stopped. Crack 2, no change until he tightened it again. After that, it did run on 2 cylinders.

[LittleWing77]

Originally Posted by jarin

Just curious if you have sorted out your M25? I'm having similar issues on mine. I changed to the upgraded alternator bracket and put on a new alternator while I was at it. After filling and burping coolant the motor was running fine although I did notice when in gear the motor seemed to bog down a bit compared to normal.

Few minutes later it turned off and I haven't been able to get it started since. I've checked and cleaned the fuel uptake pipe, replaced both fuel filters, replaced the fuel injector lines and have done my best to bleed the system according to info found here.

The glowplugs are getting voltage and do get warm but I didn't measure amperage. I've emptied the muffler and closed the fresh water seacock when cranking and it does kinda sound weird now compared to normal. This is my first boat and first time working on diesel engines so it is possible that I have screwed something up I guess.

https://streamable.com/gx23g6

Hey Jarin,

I would suggest you start your own thread, perhaps? One suggestion I do have is that you go back to whatever was the recent addition/change on your engine. Note that previously it was running fine.

Could the new alternator, its bracket or something that was moved/banged/hose split/leaking during the repair that might be implicated?

Fair winds,
LittleWing77

[jarin]

Originally Posted by LittleWing77

Hey Jarin,

I would suggest you start your own thread, perhaps? One suggestion I do have is that you go back to whatever was the recent addition/change on your engine. Note that previously it was running fine.

Could the new alternator, its bracket or something that was moved/banged/hose split/leaking during the repair that might be implicated?

Fair winds,
LittleWing77

I had seen and read so many threads on the M25 starting issues so I just didn't want to make a redundant thread. Anyway, I did get my motor running today finally!

I had the same feeling as your advice. Everything was working fine...what could have changed??

One response here talked about the flapper valve in the exhaust mixer elbow that got stuck closed and wouldn't allow the engine to start. I thought hmmm maybe when I took off the mixer off the exhaust manifold something got loose and clogged it up entirely? The current mixer elbow is a DIY from one of the POs. So I drained the coolant again and took it off and brought it home with the goal of getting the flange knocked loose and then building a new riser myself similar to the current setup.

Unfortunately I couldn't get the flange off but in the process of heating the thing and knocking it with a hammer 100 times a bunch of chunks of carbon or rust or I'm not sure what came out. I just had a feeling that was the culprit. Sure enough, started right up this morning after I put everything back together. Just waiting on a new flange so I can build a new mixer elbow now.

In the course of troubleshooting I ended up re wiring the entire engines electrical system with new wire and connectors, did the glow plug solenoid upgrade, new fuel pump, new fuel lines, new injectors and new glow plugs. So I've got that going for me, which is nice

[LittleWing77]

Fantastic, Jarin!

What a great solve!

Fair, fair winds,
LittleWing77

[donradcliffe]

An update on the battle. The engine is still winning. Did a compression test, and got 120 psi in cylinder #1, 10 psi in cylinder #2, and 250 psi in cylinder #3. Took the valve covers off, and everything is coated in water/oil milkshake and starting to rust. The dipstick is near overflowing with the milkshake, but the coolant in the header tank is clean and clear. Next step is to pull the head.

Learning things about Universal diesels. The M25 is a different bore and stroke than the M25xp. The Kubota dealer wants to know the tractor model and engine serial number.

[skenn_ie]

Head gasket, cracked head or cylinder (liners) or, if there are any, the seal between the liner and block. I suspect that it isn't intended to have a wet liner though.
Get the sump oil out NOW and refill with clean oil, no water in the jacket, take the injectors out and crank it over for 5 mins to get the oil pumped around. Cranking will be quite fast without injectors, and won't put a big load on the starter or batteries. Almost zero compression could be a stuck valve, or even out of adjustment tappet. I don't know if Kubotas have valve clearance from piston. (There is a term for engines that can do that ??).
I did work on an engine where seawater was getting into the exhaust BEFORE the gooseneck, then back through whichever exhaust valve had remained open, into the cylinder, then drain into the sump. The gooseneck had rusted so much that it broke up as I removed it. A replacement plate for between the exhaust manifold and the gooseneck was made wrong, so the same process continued. I took the head off, and couldn't see anything wrong in there and did a serious sanity check before I spotted the (someone else's) error.

[donradcliffe]

I am taking a week off to go camping, but I expect to find a blown head gasket. Catalina did not give me much access to the engine.

[sinnerman]

. I don't know if Kubotas have valve clearance from piston. (There is a term for engines that can do that ??).

They refer to it as "Top Clearance" (between top of piston and combustion chamber in cylinder head).

Measured with a plastic strips (fuse) that is flattened when the cylinder head, head gasket (and shim if installed) are assembled, torqued to spec , then dis-assembled to check the plastic strips.

The flattened strip is compared to a reference chart to determine he space.
See attachments.

[sinnerman]

Learning things about Universal diesels. The M25 is a different bore and stroke than the M25xp. The Kubota dealer wants to know the tractor model and engine serial number.[/QUOTE]

It is a Kubota D850 engine.

It is installed on the the B6200 / B6200E series Kubota.

cheers

[Stu Jackson]

Originally Posted by donradcliffe

...........................


Learning things about Universal diesels. The M25 is a different bore and stroke than the M25xp. The Kubota dealer wants to know the tractor model and engine serial number.

M25 is a D850, B6200 Kubota tractor engine.


Also check the raw water pumps seals, they are another source of cross contamination of water and oil.


Good luck.

[JPA Cate]

Hi, Don,

Do you think it would be worth while to disconnect everything, and slide the engine out for the work? It might be worth it in the long run. ...And, of course, there may be more than one thing wrong, especially now, since rust is a factor, and maybe the rings on the low compression piston shot. Don't want to leave your friend with little rusty iron bits in the pan.

Ann

[donradcliffe]

Originally Posted by JPA Cate

Hi, Don,

Do you think it would be worth while to disconnect everything, and slide the engine out for the work? It might be worth it in the long run. ...And, of course, there may be more than one thing wrong, especially now, since rust is a factor, and maybe the rings on the low compression piston shot. Don't want to leave your friend with little rusty iron bits in the pan.

Ann

Hi Ann, I am contemplating removing the engine, but looking at the installation, there is VERY little room to remove the engine without taking a sawsall to the furniture. I will be consulting with a friend who has recently repowered his Catalina 30 to see how it was done.