I should add i have also done a compression test on the cooling system. No obvious leaks. A small amount of coolant does come out the radiator cap overflow but from what i have read that may be normal. So i dont suspect a leak into the coolant system.
Jimna 254 hard starting
- Thread starter Jimmy254
- Start date
quicksandfarmer
Veteran Member
I've found that the ease of starting is very sensitive to how well adjusted the valves are.
piper184
Gold Member
How many hours on your machine?
Head bolt torque shouldn't effect starting unless they are so loose they leak.
Does your tractor have the decompression lever? If so, you need to check it is traveling properly. Also, you can use it to spin the engine up to speed and then "drop" it for sudden increase in compression. You can't start the engine with the decompression lever activated, but it will let the starter get it spinning faster, then use the inertial to your advantage. Works best in cold weather.
The throttle is your mixture control lever. Think of it as the choke on your lawn mower. There is no air control so all you have is fuel control. Too rich and it won't start. Not enough fuel and it won't start. Fortunately there is a pretty wide band of settings where it will start.
I've had mine for nearly 17 years and know all the tricks to get it started, yet it does not always fire off on the first attempt. Especially the first start of the day.
A few seconds of glow plug. The set throttle to be just barely cracked open. When it starts the setting should let it run at 1000 to 1200 rpm. Spin the starter for a few seconds and watch the smoke. If it doesn't catch in 5 to 10 seconds. Stop and hit the glow plugs for another 10 seconds while the starter cools off a little. Then hit it again. You can also try different throttle settings at this point until you find the one that works.
After it starts, the rpms will pick up a bit as it warms up, back that off until you are at ~1000 and in a few minutes it will be ready to work.
As for the thermostat, 60C is not warm enough. These little engines like to run in the 85 to 90C range. It made a huge difference in performance when I went to a hotter thermostat.
Head bolt torque shouldn't effect starting unless they are so loose they leak.
Does your tractor have the decompression lever? If so, you need to check it is traveling properly. Also, you can use it to spin the engine up to speed and then "drop" it for sudden increase in compression. You can't start the engine with the decompression lever activated, but it will let the starter get it spinning faster, then use the inertial to your advantage. Works best in cold weather.
The throttle is your mixture control lever. Think of it as the choke on your lawn mower. There is no air control so all you have is fuel control. Too rich and it won't start. Not enough fuel and it won't start. Fortunately there is a pretty wide band of settings where it will start.
I've had mine for nearly 17 years and know all the tricks to get it started, yet it does not always fire off on the first attempt. Especially the first start of the day.
A few seconds of glow plug. The set throttle to be just barely cracked open. When it starts the setting should let it run at 1000 to 1200 rpm. Spin the starter for a few seconds and watch the smoke. If it doesn't catch in 5 to 10 seconds. Stop and hit the glow plugs for another 10 seconds while the starter cools off a little. Then hit it again. You can also try different throttle settings at this point until you find the one that works.
After it starts, the rpms will pick up a bit as it warms up, back that off until you are at ~1000 and in a few minutes it will be ready to work.
As for the thermostat, 60C is not warm enough. These little engines like to run in the 85 to 90C range. It made a huge difference in performance when I went to a hotter thermostat.
Ive got a theory that it could be the positive lead connector at the battery that is at fault. Cant work on it until 2 wks time but this would explain why it would always start with jumper leads. The jumper lead was connected to the cable not the connector or the battery post so it bypassed the positive connector that looks like a copper washer with a hole in it. I had noticed that connector appeared thin and worn.
Machine has 150hrs on it but its 17 years old. Yes it has a decompression lever. 60 deg does seem too low. Where did you find a hotter thermostat? The way you describe starting is pretty much my experience except for first starts.
piper184
Gold Member
This is a cross reference sheet that came with my tractor. The hand written notes are mine.
If I remember correctly the NAPA thermostat was a few thousands of an inch too large on the outer diameter to fit in the housing. I gently filed the edge all the way around until it fit properly. The one problem I had is the old bolts that go through the housing were in really bad condition. I think two of the four twisted off and I had to extract the left over bits. Never any fun. I put in all new ones with lots of anti-seize compound on them.
It certainly wouldn't hurt to go through the head bolt torque and valve adjustment procedures.
Some of these tractors were assembled with fully painted starters which acted as insulation. The only ground they were getting was through the mounting bolts and the little bit of metal the lock washers scraped back.
It never hurts to take every electrical connection apart and clean all the surfaces until shiny metal is exposed. Starting at both battery terminals and working outward. You would be surprised how much resistance can build up on a dirty connection.
If you have the time and desire, when you get to the starter, while you have the wires off, remove the starter. Do the same shiny metal stuff at both mounting bolts and under the bosses where it contacts the bell housing. The more surface contact you have the more amps can flow through it. Also, take the starter apart and have a look inside. Clean all the contacts in the solenoid and at the commutator. A little white lithium grease on the sliding/spinning bits will help a bunch. Don't forget the bushings at each end. You will be surprised at how much more power your starter will have. All just simple maintenance stuff, just a little time consuming.
Another thing to consider is internal cable corrosion. I have seen cables that look completely fine on the outside be so corroded on the inside that they would pass only a small amount of current. For an example: The positive battery cable gets moisture inside and corrodes. You test it with a multi-meter and get battery voltage at the far end. This is fine when there is no current flowing through it, but as soon as you put a load on the cable, it becomes a big resistor and all of a sudden you are only seeing 8 or 9 volts. The tendency is to think "oh, oh, the battery is bad". That happens but if your pretty sure it is not that case, use a set of jumpers to bypass the vehicle cables.
If I remember correctly the NAPA thermostat was a few thousands of an inch too large on the outer diameter to fit in the housing. I gently filed the edge all the way around until it fit properly. The one problem I had is the old bolts that go through the housing were in really bad condition. I think two of the four twisted off and I had to extract the left over bits. Never any fun. I put in all new ones with lots of anti-seize compound on them.
It certainly wouldn't hurt to go through the head bolt torque and valve adjustment procedures.
Some of these tractors were assembled with fully painted starters which acted as insulation. The only ground they were getting was through the mounting bolts and the little bit of metal the lock washers scraped back.
It never hurts to take every electrical connection apart and clean all the surfaces until shiny metal is exposed. Starting at both battery terminals and working outward. You would be surprised how much resistance can build up on a dirty connection.
If you have the time and desire, when you get to the starter, while you have the wires off, remove the starter. Do the same shiny metal stuff at both mounting bolts and under the bosses where it contacts the bell housing. The more surface contact you have the more amps can flow through it. Also, take the starter apart and have a look inside. Clean all the contacts in the solenoid and at the commutator. A little white lithium grease on the sliding/spinning bits will help a bunch. Don't forget the bushings at each end. You will be surprised at how much more power your starter will have. All just simple maintenance stuff, just a little time consuming.
Another thing to consider is internal cable corrosion. I have seen cables that look completely fine on the outside be so corroded on the inside that they would pass only a small amount of current. For an example: The positive battery cable gets moisture inside and corrodes. You test it with a multi-meter and get battery voltage at the far end. This is fine when there is no current flowing through it, but as soon as you put a load on the cable, it becomes a big resistor and all of a sudden you are only seeing 8 or 9 volts. The tendency is to think "oh, oh, the battery is bad". That happens but if your pretty sure it is not that case, use a set of jumpers to bypass the vehicle cables.
Some great info there. Cleaning takes time but not as much time as buying and fitting parts that dont fix the problem. That chart wil come in very handy, thank you. How old is your tractor? You said you have had it for 17 years. Was it new. So far all the bolts ive undone have been in very good condition which i am surprised by given its had many years outdoors (not near the ocean though). My thermostat housing bolts were like new. The only trouble i had was trying to fit a new fuel filter tap and bowl into the tank but the new filter thread was bad quality.
piper184
Gold Member
My 284 was made in October of 2006. I got it in Jan of 2007. Tractor, backhoe and front end loader all in the factory crates. Put it together in my shop. Plowed snow with it that winter, then used it to install a new septic system the next summer. It's not perfect (people sneer and look down at their noses at me because it doesn't have hydro-drive or a cab) but it is simple to work on, and fairly durable if you don't abuse it. Price was right too.
Old chinese proverb which I made up myself just now. 'People who sneer down at cheap tractor owe lots of money'
I alternate between thinking this is a bargain and this is a lemon at least twice a day. I think it will be fine though. It's almost there. To think that a faulty fuse blade can bring a couple of tonnes of machinery to a standstill and take more than a day to fix it isn't surprising that things sometimes just need a bit of attention. I'll be using mine for clearing a bit of light scrub and forest litter, firewood, track maintenance with the box blade, landscaping etc etc. Backhow should be handy too. I hope to find a bit of clay i can use for repairing a dam. Backhoe is off at the moment, it has a fairly decent hydraulic fluid leak in a spot where I can not figure out how to get too. Its is probably just a loose fitting.
Can you please point me in the right direction for the valve adjustment procedure and the head torque specs.
I alternate between thinking this is a bargain and this is a lemon at least twice a day. I think it will be fine though. It's almost there. To think that a faulty fuse blade can bring a couple of tonnes of machinery to a standstill and take more than a day to fix it isn't surprising that things sometimes just need a bit of attention. I'll be using mine for clearing a bit of light scrub and forest litter, firewood, track maintenance with the box blade, landscaping etc etc. Backhow should be handy too. I hope to find a bit of clay i can use for repairing a dam. Backhoe is off at the moment, it has a fairly decent hydraulic fluid leak in a spot where I can not figure out how to get too. Its is probably just a loose fitting.
Can you please point me in the right direction for the valve adjustment procedure and the head torque specs.
piper184
Gold Member
Head re-torque starts on page 34 of the first document on this page:
The second document on the web page has lots of good info and drawings in it too. I don't see the specs for the valves. I will have to do some digging on that.
Harnerfarm Jinma 284
www.harnerfarm.net
The second document on the web page has lots of good info and drawings in it too. I don't see the specs for the valves. I will have to do some digging on that.