jinma 254 - complete rewiring and other questions

[farmerben8]

So just I bought a Farm Pro 2425 (basically the jinma 254) that was next to a building that burned down a few years back. The hood, dash, steering wheel and wireharness were all melted. The tractor runs fine (except for what seems to be a rear main seal leak, and a slight hydrolic leak beneath the drivers seat on the right hand side, Ill get to these in another post later), and the owner has been using it for a couple of years without live power, gauges or lights. It starts by jumping the starter solenoid with a screw driver!
Ive been doing some homework, downloaded 2 manuals and 2 different wiring diagrams for this tractor series, and have my head pretty well wrapped around what needs to happen to get some gauges, switches, the lights, etc set up. I would, however, appreciate some opinions and ideas.
My plan as it stands is to NOT buy the factory hood and dash, but try to find something to patch together a cover for this thing. The previous owner put together a light weight aluminum frame and some mower hood which actually fits quite nicely on the front of the thing, Im just going to extend that theme rather than go the $650 for the factory hood!
Electrically, I plan to install the factory fuse box (new style) which includes relays for the horn, the flasher for directionals, and I believe the voltage reg for the alternator. Im going to buy the switch cluster for the lights, already ordered the John Deer ignition switch and do plan on using a relay for the glow plugs to avoid pulling much amperage through the ignition switch. The gauges is where Im having some deliberation. Why should I buy the jinma guage cluster vs a set of david brown guages (or something comparable) on ebay for a whole lot less? Im planning on buying all the oem stuff from circle g tractors, just wondering if I need to go stock with these items or if I could patch together something else for cheaper. I know this Jinma stuff is probably all calibrated oddly and the sending units that are in the machine at the moment (if they even still function) probably wont work with other guages, so I will have to possibly buy matching senders for different gauges. Ive just got more time then money, and like tinkering with this kind of stuff so am basically wondering can I find other senders and guages for cheaper, and might they be more reliable in the long run if they are US made? I could also possibly live without a fuel gauge and rpm/hr meter. The oil presssure and water temp I thing are kind of important and the amp meter is helpful. The others would be nice i guess, just not totally necessary!

Ok, thats the first set of questions. Secondly, why does the oil fill plug on the valve cover have a threaded hole in it? Is this for blowby from the engine? Seems kind of strange to me.... Mine is wide open, and since i dont have a hood covering it, this seems a bit problematic... should I plug it, or try to find a nipple that fits the thread size, then put a little tube on it to bend over so rain and stuff wont go in the engine?!?

Thank you for any help or opinions ahead of time. I am excited about getting this tractor wired up and running and look forward to participating in these forums here.

- Ben

 

[Rich Waugh]

First off, you want to look really closely at that suspected rear main seal leak. On my 304 Jinma, and others I've heard about, the leak was not the rear main seal but was actually the oil sump to flywheel cover gasket, caused by sloppy assembly at the factory. If I hadn't addressed mine immediately, I might have ended up with a broken bell housing. The bolts from the the flywheel cover to the engine block were loose enough that several could be removed with my fingers! I did replace the rear main seal while I was at it, but the original appeared to be fine. The whole saga is here: Major Tractor Woes in Paradise | CHINESE TRACTOR WORLD FORUMS You might want to check yours out closely to avoid problems down the road.

As for the electrics, I'd pass on the OEM switches and use marine stuff. Cost will be about the same, but the quality is worlds different. Ditto for the gauges - just get the appropriate senders and you're good to go. As for the fuse block, I strongly recommend getting a good aftermarket assembly from a major manufacturer of quality components. My OEM fuse block is definitely on the low end of the quality scale and has caused problems from the start. I replaced my alternator with a Delco 12Si with the integral regulator so I cured many problems right there and got a 65-amp alternator to handle the extra lights and inverter. Total cost was under a hundred bucks and almost a direct bolt-on swap - I just had to modify the mounting bracket arm and swap the pulley. I also changed to a link belt which means I 'll never have to remove anything to change the belt. I bypassed the OEM ammeter and added a voltmeter instead. It's a modification I highly recommend.

On my 304 Jinma, the oil filler cap is threaded also. I am not aware of a threaded hole in it, but it may have one - if so it is very small. It is vented, but just barely. Your plan seems reasonable. I do, however, recommend that you use the other oil fill point if you want to get the oil in the sum in a reasonable time frame. The holes from the valve train down to the sump are tiny and take forever to drain down, while the other fill tube on the side of the block goes directly to the sump. It should have a red painted cap, but the fire may have ruined the color.

The tach and hour meter are essential - how else can you properly operate the engine and know when service is due? Either get new OEM stuff or get aftermarket stuff, but definitely get a tach and hour meter! The tach sensor is a pickup mounted in close proximity to the flywheel and I'd bet that there is an aftermarket assembly available somewhere if you look hard, or get the OEM unit. There is a company that makes a nifty aftermarket tach and hour meter unit, but i can't recall the brandname - something like MiniTach or similar. I think Bob Rooks will know - I believe he's the one who turned me on to it.

 

[Affordable]

We have a wiring harness for these tractors, you still have to put the wire ends on, the original tractors had seperate. gauges so you don't have to buy the cluster, on the valve cover fill plug, there is a hose that attachs to it and goes to the intake. We also have a few used hoods that came from FarmPro, that need repainting ,we bought out most of there parts when they shut down. Send me a complete list of things you are looking for, I may be able to make you a discounted package deal on them, you never know

tommy@affordabletractorsalesco.com


Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[Rich Waugh]

You can't go wrong dealing with Tommy. He'll definitely treat you right and he knows more about these tractors than most of the people at the Jinma factory, too. He's my go-to guy for accurate information and parts every time.

 

[RonMar]

The tach will be the hardest to overcome. Tinytach is probably the easiest option if you don't want to go the factory route. All other gauges are common automotive. +1 on the aftermarket fuse block. I would put on a more common alternator with internal regulator. This would significantly simplify the wiring. A Mazda B2000 PU alternator is nearly a direct bolt on. Seems there was another model that can be easilly fitted to the factory bracket.

If it were me, I would build a new cowling instead of adapting something else. This would allow me to incorporate some changes such as a lower profile to enhance visibility, and perhaps blend it into a cab.

That hole in the oil filler cap should have a hose barb screwed into it with a hose that runs over to the air intake plenum. This vacumes out crankcase gasses into the intake and helps keep the case under a vacume. This helps to reduce oil leaks and helps prevent unburnt diesel fumes from diesel that makes it past the rings and into the oil sump. This diesel when heated in hot engine oil vaporises and these vapors can accumulating and possibly cause a crankcase explosion...

 

[RonMar]

ok, so ive been studying this diagram: http://www.tractorbynet.com/forums/...tric-diagram-wiring-diagram-cluster-gauge.png and it seems that the fusebox assembly has one live power input from the ignition switch. Seems sketchy unless that thing is extremely stout! So if im going to purchase a non oem fusebox set up, it needs to be one with a single live feed, rather then those with two poles for each fuse (im assuming these are just inline fuses...)? But the glow plug circuit will need a separate fuse... i think... Looking at those diagrams for two long can be confusing!

The main power on that drawing flows from the battery via the starter thru wire 2 to the top 30A main fuse. Then it passes on to the amp gauge via wire 3. From the other side of the amp gauge it is on to the ignition switch via wire 5. When the key is turned on the power flows back to most of the rest of the fuses via wire 6. From there it passes thru those various fuses to power the different circuits. One exception is wire 12 which feeds current from the key thru the glowplug fuse to the plugs when the key is in the heat position. The spinning alternator generates electric current which it feeds back into the system via wire 4. It puts the energy back between the amp gauge and the key switch so that charging current going back into the battery can be seen by the amp gauge.

If your only fuse block option is one with a single common feed point, you need one with 5 or 6 fuse positions. The main fuse and the heater fuse can then be replicated seperately with single in-line fuse blocks.

 

[farmerben8]

Thanks Ron, that gives me a better view of whats happening there. I realized I had it a bit wrong and deleted that post. Its gonna take some thinking about before Ive got my head around it all. Im sure Ill be hitting you up for advice again before I make a final decision. Also, i checked out the tinytach, it looks like a good option for me! This being a chinese engine I should probably go with the metric 6mm transducer?
Ive got the Y385t engine, and it does have a nipple on the side of the valve cover that goes into the air intake manifold. This hole in the oil fill cap I believe should just be plugged?
Ive inquired with Tommy about getting a used hood assembly, I like the rustic look, but it'd be nice to get the thing looking halfway right, and Im not a fabricator when it comes to body stuff... i can patch things ok, but making panels from scratch is a whole other skill level We will see whats in my price range.
Rich - Will the access panel on the right side of the bell housing give me a look at those flywheel cover bolts? At least that side? It seems I will need to split the tractor to do either job. Maybe this should be the first thing I do... Also, what Island are you on? my Brother worked on a little farm on St John years back... ya never know!
Thanks again everyone! The help is very appreciated!
- Ben

 

[Rich Waugh]

Ben,

I'm on St. Croix, the "big" island. Sadly no, you can't see the flywheel cover to block bolts through the bell housing access port - at least not worth a darn, anyway. Even if you could see anything, you couldn't actually DO anything constructive, so why bother? You bite the bullet, take the Valium, split the tractor, and do it right - you'll feel a whole lot better afterwards, to say nothing of feeling completely empowered as a budding diesel mechanic. At least I did. (grin) In truth, I feel a whole lot more secure that my engine is going to stay together for a long time now after having done mine, and I did learn a lot about tractors in the process of terrifying myself.

The Delco 10Si and/or 12Si alternators are a near-perfect bolt-on for the OEM regulator. (Which is what the Mazda uses, I believe.) Swap the OEM pulley onto the Delco with the spacer washer reversed and possibly modify your tensioning bracket to get the proper clearance from the other stuff and you're good to go. One wire to the battery or one to the battery and one to the main power buss (for field excitation), depending on particular model and you're set. 45-100 amps for under a hundred bucks with some careful shopping on Ebay. Tough to beat that. I can now run my high beams and my flood lights and my back floodlights all at once with no sweat, or fire up my 2KW inverter to run power tools with no fear. I love it.

Yeah, get the bonnet from Tommy - it will save you a week of frustration and look better int he end. Painting is easy compared to sheet metal forming.

If your brother is still into farming, there is a relatively new (5-8 yrs) organic cooperative farm operating on St, Croix, run by a friend of mine. Nice operation. Ridge to Reef Farm, St Croix USVI - Ridge to Reef: Virgin Islands' Source for Organic Farm Grown Produce and Farm Stays I live on one of their satellite facilities, actually.

 

[farmerben8]

Well, now i'm the farmer of the family, so go figure. Looks good though, would love to do some farming in the tropics one day.
Ok, think im going to take the plunge and get the hood assembly and most of the gauges, senders and wire harness from Tommy, going with US brand switches and fuse block. thanks for the advice on that.
I will split this thing and figure out the oil situation soon. Also, Im wanting to do a complete overhaul, tune up of the machine, changing all fluids and whatever other maintenance is a good idea at this point. I have a slew of questions regarding this work, and realize the information may be somewhere in the depths of these forums, non the less... :
Not knowing how many hours are on the machine, should I just do the 500 hr maintenance tasks as suggested in the manuals?
Any resources out there for specific torque measurements of bolts like the flywheel and bellhousing?
What is the appropriate valve lashing setting for these engines?
Fluids, what weight engine oil? 15w-40 is what I use in my Isuzu diesel pick up. Is this appropriate for the Jinma?
Filters for fuel, oil, and hydrolics... what are the american cross over brands and part #s?
Any other suggestions for care/maintenance at this point?
Thanks y'all. Im excited to get into this project real soon!
- Ben

 

[NT304]

I had a terrible scare last winter during a storm after my ignition switch broke. I started the machine with the screwdriver as your previous owner had done. About the 5th time doing this, I forgot to put the tractor in neutral. Fortunately for the large woodpile immediately behind my machine, or I probably would not be here today. I ordered a new switch from Affordable that night, and now heed the advice of a local farmer who once told me "never ever ever start the machine unless you are in the seat".