Siromer 304 (Y385T engine) using decompresser when starting

   / Siromer 304 (Y385T engine) using decompresser when starting #1  

aesmith

Silver Member
Joined
Jan 15, 2018
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116
Location
Scotland
Tractor
Siromer 304 (Y385T)
Hi,

We recent got a Siromer 304, similar I think to Jinma 254, it's a four wheel drive with Y385T three cylinder engine. It's slow to start in cold weather, I've already replaced a faulty glow plug and I'm going to look at a relay and heavier gauge wire as well. However I noticed some comments about using the decompresser when starting. What do you guys do, do you spin it up to speed decompressed, then flip the decompresser off to get her to fire up (like hand starting a cement mixed)? Or do you just spin the engine a bit decompressed before even trying to start? Our tractor doesn't have any remote control for the decompresser, just the lever on the back of the rocker box, however I'm sure it would be easy enough to rig something up.

Thanks, Tony S
 
   / Siromer 304 (Y385T engine) using decompresser when starting #2  
I spin it up to speed decompressed, then release the decompression lever to start. I use it every time I start. Couple of benefits: allows the starter to spin up to speed with less load so lower brush and battery currents. If something has leaked and there is fluid in a clinder it shouldn’t hydraulically lock and possibly bend a rod or twist a crank. Spinup without compression load allows oil pressure to build in crank and rod bearings before they are loaded which should extend their life...
 
   / Siromer 304 (Y385T engine) using decompresser when starting #3  
   / Siromer 304 (Y385T engine) using decompresser when starting
  • Thread Starter
#4  
Thanks for both suggestions. I'll see if I can rig up a remote control for the decompresser and see how that works.

Regarding the coolant heater, it's true that we have power in the shed where the tractor will normally be kept, however we're the other side of the pond from Texas, and our power is 240V so it maybe something I'd be better of sourcing locally if I go down that route. Really I'm hoping that beefing up the supply to the glow plugs will sort it.
 
   / Siromer 304 (Y385T engine) using decompresser when starting #5  
You can also fit an external tank type coolant heater to this engine pretty easilly. I put a 1KW unit on the left side, I supply water to the bottom of the heater from the block drain and the heater outlet goes up to a port near the thermostat housing. I think that port was used to feed a cab heater, but it works great to heat the head and block. With the heater plugged in, it thermosiphons and hot water rises from the heater and enters at the top port and circulates down thru the head and block to return back to the heater. 10 minutes of that and the head is nice and warm and she starts cleanly...
 
   / Siromer 304 (Y385T engine) using decompresser when starting
  • Thread Starter
#6  
Thanks for the comments. I tried with a improvised link to the decompresser lever, it should be possible to fabricate some sort of proper linkage. It won't be the magic bullet I don't think, because the engine needs to keep cranking for quite a while after it starts to fire. Need to rig up the relay and feed to the plugs. Where do you guys recommend taking the feed? I was thinking of mounting the relay above the fuel tank next to the existing fuse box. Could take feed from the starter motor (with inline fuse in the cable). Looks straightforward but maybe fiddly to get correct.
 
   / Siromer 304 (Y385T engine) using decompresser when starting #7  
A high current feed from the starter is probably the easiest and most effective. But it might not be a magic bullet either. Glowplugs help but they only provide so much heat. How cold are we talking about? If it is really cold soaked, the only magic bullet is a coolant heater...

Another general starting tip I can offer is when you shut it down, put the throttle to a position where the engine is idling about 1200 RPM and leave it there, then pull the shutdown cable. When you start it and it fires, it will increase in RPM, you need to pull the throttle back to stop that rise at around 900 RPM(normal idle). What works well for me is that when I drop the key my hand goes right to the throttle to catch the rpm rise at 900... what this does is insure enough spring pressure to pull the rack fully open so you are getting full fuel delivery for startup... on mine the 1200 rpm position on the throttle lever is right alongside a hydraulic pressure gauge I put on the loader valve input so on mine it is easy to make sure it is far enough forward. You also need to insure the shutdown cable is fully releasing the shutdown lever on the injector pump...
 
   / Siromer 304 (Y385T engine) using decompresser when starting
  • Thread Starter
#8  
A high current feed from the starter is probably the easiest and most effective. But it might not be a magic bullet either. Glowplugs help but they only provide so much heat. How cold are we talking about? If it is really cold soaked, the only magic bullet is a coolant heater...
Not that cold by continental or US standards, yesterday was probably -4C (25 Deg F) when I fired her up. That took several goes, each time around 20 sec of glow plugs, then cranking. While cranking the engine fires immediately but not strongly enough to keep going unless I keep the starter running for maybe 5 or 10 seconds after it starts firing. This is the only Diesel I've ever had that behaves that way, but there are Youtube videos of Jimnas that seem a whole lot worse. So not really sure if mine has a fault, or if it's normal.

Regarding the glow plugs, my thoughts were that they're supposed to work by providing a very hot point to start ignition, but if they're not getting enough current maybe that's not happening and all they do is put some general heat into the cylinder head.

Really hoping that winter use isn't going to depend on an electric heater.
 
   / Siromer 304 (Y385T engine) using decompresser when starting #9  
On my DF when cold always have the manual throttle part open before cranking. On really cold days full open. Careful to monitor engine revs as it warms up and slowly back it back off.
 
   / Siromer 304 (Y385T engine) using decompresser when starting
  • Thread Starter
#10  
Right, just done a couple of tests with what I have to hand. Voltage across the heater plugs only around 6.5V using the existing control and wiring. No wonder they don't work very well. I found a bit of scrap heavy cable (maybe 6mm sq) which already had an 8mm ring on one end and 5mm on the other. Added a scrap push button in the middle and connected this from the permanent live on the starter, round the dash and back to the heater plugs. Reconnected battery. Gave it 10 seconds with the push button then hit the starter and she fired right up. Just above zero this afternoon, so not a real cold cold start, but it's never before fired up without at least 30 seconds of heat even on quite a mild day.

Just need to order the bits to do it properly, including a fuse in the live feed.
 
 
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