Universal m25 header tank

[maqrol]

I have a Universal M25 engine in my boat and it has seized. I need to take the cooling system header tank off to remove the cylinder head. I cannot work out how it is attached. Can anyone help me with telling me where the attachments are. I have disconnected the alternator support from the front and two 10mm nuts on the side, but it is still held tight so I guess there is another two or three bolts somewhere else.

Thanks for any help

 

[Me and Boo]

Marine Diesel Direct has Universal information.

 

[maqrol]

Thanks a lot. This has answered ALL my questions!

 

[Maine Sail]

I have a Universal M25 engine in my boat and it has seized. I need to take the cooling system header tank off to remove the cylinder head. I cannot work out how it is attached. Can anyone help me with telling me where the attachments are. I have disconnected the alternator support from the front and two 10mm nuts on the side, but it is still held tight so I guess there is another two or three bolts somewhere else.

Thanks for any help

There are six manifold bolts holding it on. You may need to give it a tap with a wood mallet to break it free of the gaskets.. It then needs to slide off the manifold bolts so you will need about 4" -6" clearance on that side of the engine to get it off.

Why did it seize? Was it sudden? Try pulling the injectors or glow plugs and turning it over. If any water is in the cylinders this will expel it. When you put it back together you should consider stripping it and painting it PLUS doing the alternator bracket kit upgrade if your engine does not already have it.


Oh look, you're in luck. I snapped a photo of it.....

If your alternator bracket does not look like this one you will need to replace it!

 

[Stu Jackson]

Here's a lot of M25 engine information

http://c34.org/bbs/index.php/topic,5078.0.html

http://www.c34.org/wiki/index.php?title=Diesel_Engine

 

[maqrol]

Thank you for the photos. They are a real help.

The engine just stopped. The previous day going around the Mull of Kintyre with a strong swell and overfalls the engine had occasionally laboured -rather like a car going up a hill - but only for seconds. I thought it was because of the sea conditions. The oil pressure and temperature were normal.

It was working perfectly when it seemed to labour, then recovered and then stopped. No bang, no smoke. The oil pressure and temperature were normal. We were in flat calm conditions and a 6 kt tidal stream. Fortunately a larger yacht was close by and towed us to Islay. The local mechanic did not have time to do more than a cursory exam and confirm it was seized. I sailed back to my home port and now am starting to strip the engine down. My suspicion is a broken piston ring.

 

[Stu Jackson]

Have you checked the anitsiphon valve at the inlet nipple on the exhaust riser?

 

[Bob S]

I'm sure you mechanic checked but I had the same symptoms when my fuel pump died.

 

[maqrol]

Thanks for the suggestion. I will check the pump before I attack the head. I can understand how a mechanical pump can seize the engine, but not an electric pump. As a European I am not used to electric fuel pumps on small boat Diesel engines! In Europe Beta Marine engines have mechanical pumps and most small Kubotas also have mechanical pumps.

 

[jibes138]

Your Universal engine is a Kubota that has been modified by Universal to add the sea water cooling system and a transmission for your rather simple needs of one speed marine propulsion. So the motor still has a mechanical fuel pump. You can get the exploded views of the engine internals and a parts list at marinedieseldirect.com that should help you visualize your motor.
You refer to the motor as "seizing." Is this the correct term or did the motor simply fail and stop running? If it is "seized" I think of that term as you are unable to turn the crankshaft at all. Will the motor turn over with the starter but just not start? Or is it truly "seized" and has no motion of the crankshaft at all?
To help with suggestions we need to understand whether it is a fuel system issue (won't run) or something like a true seizure from lack of oil or other catastrophic failure.

 

[Bob S]

If it was the pump it will still turn over but won't start. Those symptoms happened to my M25 and I ended up adding a clean out port in the fuel tank and all new fuel line from the tank to the engine along with a Facet Cube fuel pump recommended by Maine. If the engine won't crank over it could be seized.

 

[Stu Jackson]

Thanks for the suggestion. I will check the pump before I attack the head. I can understand how a mechanical pump can seize the engine, but not an electric pump.

The electric pumps are often called "lift pumps" because in many boats the fuel tank in below the engine. The mechanical pumps aren't strong enough to lift the fuel to the engine. On our boat the fuel tank is higher thasn the engine, but we also have an electric pump that runs all the time. I agree, check the pump first. Much pump material available in my earlier links.

 

[maqrol]

Thanks everybody for info re pumps. The engine has seized and does not turn with the starter. The engine is a refurbished engine that comes out of a Catalina and replaced a 50 year old Volvo in my Kings Ametyst last year. As I put in the first post the engine just stopped with oil pressure normal and temperature also normal.

 

[Stu Jackson]

Don't know if you're going to rebuild or replace. For some info and pictures of more M25 "guts":

http://www.c34.org/wiki/index.php?title=Rebuilding_the_M25-XP

Wander around the wiki, there's much more M25 series info there.

Good luck.

 

[jibes138]

Stu,
Great photos. Hard to believe that level of rebuild without pulling the engine from the boat? I don't know your installation but i doubt I could drop my pan in place let along get at the rods and crank to connect the pistons. They really look simple yet inspire fear in all of us.

 

[Stu Jackson]

Universal M25 - Series Engines - Just The "GUTS"

Dave, thanks, but for those of you "who read rather than just looking at the pictures!" , it is NOT MY engine. Dave Sanner is our C34 Webmaster and one heck of a great sailor and another one of "The Good Guys."

I always did like cartoons better, Cliff Notes, too.

 

[jibes138]

Sorry Stu, I realize that was someone else's post. I was just wondering on your C34 if you would be able to pull the pan to get at the rod bearings and pull the pistons? On my O'35 I can barely get my hand under there to put in a sheet of oil absorbant mat never mind dropping the pan. That boat in the post had a huge amount of space to get at the bottom of the motor. I would be happy if they put the motor right in the middle of the cabin at waist height, or maybe build a decoupler system and a track so you could release it, pull it out on the track, work on it then put it back. Let me know when you have the designs roughed out for my review! This Friday works for me.

 

[Stu Jackson]

OK, Dave, I'll take the whole weekend off and join you! A quick coupler and two railroad tracks oughta do it!

Dave Sanner's boat and mine are identical. I don't know how he did it, but I'm pretty sure it was with a ratchet extender and a universal joint. Some of them can be accessed from the huge aft cabin access panel under the berth. It's pretty good access to our engines. But, but, but, getting it off is only half the job. Gasket and lining up holes had to have been very, very interesting.

 

[damauney]

Dave

Just lifted the engine on my O35 to change the mounts and while I was at it lifted it further to get the oil pan higher than the front cross member we have. I removed the oil pan to wire brush, inspect and paint. You can get to the con-rod caps but space is close. Used 4x4 across companion way with rope come-along and the rope vang aft around the fuel tank to keep it from swinging. It would not have been a big deal to let it swing out onto the soul. Most critical is watch the dip stick tube. Very close to port side support.

Goodwinds
DaveM