Starting my new Jinma

[UncaFarfel]

Happily messing about with my new JM284. But it seems tricky to get the engine started using the recommended procedures. I've zero experience with diesels, so I'm not sure what's the best practice to follow.

The users manual says you should only crank for 5-10 seconds for each start attempt ... & then wait 2 minutes before the next attempt. I'm using 20 seconds of glow plug power because it's been around 20 degrees F hereabouts. It takes quite a few tries to get the engine going. Is that normal? The two minute time-out seems awfully long ... is it just to make sure the starter doesn't overheat in the middle of the summer? And can I run the glow plugs much longer than 20 seconds or will they burn out? Or is the the two minutes rest supposed to keep me from frying the glow plugs mid-winter, so I can really crank like a fool in milder weather? And what's generally a good throttle position while cranking?

I guess I'm hoping for a few starting hints for a novice.

Thanks!

 

[billbill1]

My 284 had a bad starter when it was new, replaced for free from my dealer. I bought a lower radiator heater from NAPA and I plug the tractor in for 15-45 minutes and it starts right up. Many (me included have replaced the starter switch) with a Ford switch that keeps the glow plugs firing while the starter is engaged and this helps too. These tractors are cold blooded and these two things (about $60) will improve the starting. After plugging the heater in, my tractor starts like it's already warm, without the coughing and belching. 20 seconds on the glows is plenty and the tractor will start quickly if you warm it up. 10 seconds on the starter is to save you $250 on a new starter.

Read the posts in the Chinese forum and you will find the starter switch part # and I believe the lower heater hose is 1-1/4" dia. The one I bought is 500 watt.

 

[jaroban]

I would highly recommend that you change the starter switch to the ford switch. The switch that I bought does not come with the key or the nut that holds it in place. Jinma has a bad reputation when it comes to cold starting. You might also check to see if your glow plugs are good. there are many post on this forum about this matter. Good luck, Robby

 

[greg_g]

</font><font color="blue" class="small">( I'm using 20 seconds of glow plug power because it's been around 20 degrees F hereabouts. )</font>
You didn't mention throttle. The hand throttle should be set at about 50% before cold starting. And you won't be sorry for changing over to the Ford-type switch. A lot of folks also upgrade the OE battery and cables. Short of that, Jinma glow plugs are cheap - about six bucks a pop - and very easy to replace if/when necessary. Glowing a stone cold Y380 or Y385 engine for only 20 seconds at 20F is insufficient. In single digit temps, I've held mine for as long as a 40 count.

One way to observe the effect of glow plug heat is to watch the ammeter. When first turning the key over to the HEAT position, the ammeter should take a very big jump. They're not very accurate gauges, but take note of about how many amps are initially indicated; let's say ~25A. Resistance changes with temp, so as they heat - the amp gauge needle should start to drop. When you see the needle drop to - say, ~17-18A
1. open the compression release and hold
2. quickly switch from HEAT to START
3. spin the starter about 3 seconds
4. close the compression release
5. engine starts, return key to RUN
After trial and error, you should be able to find a co-relation between ambient temp and glow plug amps to know about when they've done their job. Remember, resistance changes with temp - inside the engine and out. You'll have to tailor this procedure to your own starting conditions.

The wait between starts is indeed to permit the solenoid/starter/battery/cables to cool down. It's a generic recommendation though, one which you can adjust for conditions. Feel the four components after a 30 second crank, use your judgment from there.

//greg//