Oil & Fuel Jinma 254 Won't Start After Oil Change

[quicksandfarmer]

On my Jinma 354 if the pump is deadheaded it will keep the starter from turning the engine.

Until you figure out what the problem is I wouldn't use the starter, I'd turn the engine over using a socket on the nut on the pulley on the crankshaft.

 

[Rich Waugh]

Good point on the hydraulic pump, Ron. I did once deadhead mine that way and it didn't start, fortunately, but was very close to it. Had it fired, that would have ruined something for sure. There was asurprising amount of resistance from the very first, but it definitely did a few revolutions before it stopped.

 

[skinny49]

I did the same thing on my Jinma's 284 first oil change. I poured in the oil too fast with a big ole funnel and hydro-locked the engine. Just pull your glow plugs and turn the engine by hand.

 

[Diamondpilot]

I did the same thing on my Jinma's 284 first oil change. I poured in the oil too fast with a big ole funnel and hydro-locked the engine. Just pull your glow plugs and turn the engine by hand.

I maintain well over 75 pieces of equipment and do about 125 oil changes a year. Been doing this for about 25 years now and have never done this. Only time I had a engine hydro locked was when we sunk one. Just pulled the spark plugs and cranked it over, changed the fluids, fresh gas and air filter and she was fine.

Chris

 

[skinny49]

First time for me, I have changed a lot of oil. I think if you add the oil too fast on that engine you will fill the valve cover. Then the oil will drain through the vent tube into the intake and into a cylinder through a open valve.

 

[RonMar]

It depends on how the vent is plummed. On my Jinma 284, the vent is connected to the oil fill cap, so forcing oil into the intake manifold while filling is not possible this way... A vent plummed directly to the valve cover could allow this to happen though.

I am not sure how the valve guides are sealed in these engines. They might not even have valve guide seals, just raised guides so normal oil flow in the head dosn't get high enough to allow anything but casual splash leakage/lube down the guides. If this is the case, an overly full valve cover during a fill might have allowed oil to pass down along a open valve and have the same effect. It dosn't take much oil to lock a cylinder...

 

[quicksandfarmer]

If you turn the engine slowly by hand you'll get an indication of the problem. If it's oil locked it's locked at all speeds. If the hydraulic pump is dead-headed you might be able to turn it slowly.

 

[MondelloRanch]

Just to close the loop, the winner is ..... oil in the #2 cylinder! Removing the glow plugs is definitely the way to go, it's a lot easier than messing with the injectors. Once I got them out I cranked it over, it blew a geyser of oil out #2. I let it sit for a couple of minutes and did it again, lo and behold another geyser of oil shot out. Cleaned off the glow plug and reassembled, and it fired right up on the first try. I'm happy again.

On a side note, the engine has a bracket for a "pressure reduction mechanism," and the lever and return spring is there. When you push it, though, it doesn't feel like it's actuating anything (and it certainly didn't help me clear the oil). I wonder if the rest of the mechanism isn't installed. It's listed in the parts diagram for the engine.

Now I just need to devise a way to keep this from happening the next time I change the oil.

 

[Rich Waugh]

You can pull the valve cover and see if the inner parts are in the proper place to lift the exhaust valves. Often they are assembled incorrectly and don't do anything, but setting them up correctly will be easy enough. Once that is done it shouldn't be too tough to rig a linkage to allow you to release the compression from the rider's seat. I'm not at l surprised that it was hydrolocked - I've read of numerous others who have had the same issue. Glad you got it resolved.

 

[RonMar]

Compression release is a good thing to have. Diesel starters have a lot of torque. If somehow you get water down the exhaust or oil into the intake to foul a cylinder, an engine can develop enough torque when cranked that when the piston locks, rods can be bent, cranks can be bent/twisted... Compression release gives this fluid someplace to go. Most engine wear comes at startup as it takes some time to build oil pressure. Use of the compression release allows the engine to build some oil pressure in the crank before the severe loads of compression are applied to the bearings. It also saves wear and tear on the starter by allowing it to spin-up to RPM under the lightest load possible.
I use mine on every start, crank till I see oil pressure and drop the lever and away she goes...