25 hp jinma tractor starter drags

[johnk]

Soundguy,

Nicely stated.

 

[quicksandfarmer]

Lot of small gauge wire resistance in that path. It's for that reason that I have added a length of insulated 10 gauge primary wire, directly connecting the alternator output and the starter end of the battery cable. Up side is good charging voltage at the battery. But since electricity takes the path of least resistance (10ga) major ammeter deflections are dampened significantly. I think a more sensitive meter movement would fix that little problem. But I think improved starting voltage is more than a fair trade-off for a less accurate ammeter.//greg//

I would worry more about the resistance of poor connections than undersized wire. The OEM alternator is only rated at 14.5 Amps, which 14ga wire should handle with no problem. Considering the short distances involved you could probably go down at least two sizes..

Even with resistance in the circuit the battery will charge completely, it just might take a little longer. As the battery approaches alternator voltage, the current in the charging circuit drops off proportionately, until at fully charged zero current flows. With zero current there is zero voltage drop, and the battery will be at full alternator voltage. It might just take a little longer if there is additional resistance in the circuit.

 

[Soundguy]

The OEM alternator is only rated at 14.5 Amps, .

Wow! Now i don't feel so bad about my old tractors with generators... while they are not great at idle.. they can kick 20-25a at rated rpm.. even the old 6v ones.

How much those little alternators cost? I'm guessing pretty economical price?

Soundguy

 

[greg_g]

Even with resistance in the circuit the battery will charge completely, it just might take a little longer.

That's the whole point. I'm guessing you're never actually performed a voltage loss analysis on your tractor circuits. Plus, I think you have your amps and volts mixed up. A typical 200 series alternator is rated to put out a nominal 25 amps (350 watts/14 volts). I converted one of my Chinese alternators to a 1-wire last week, and it bench tested at 35+ amps and 14.5 volts.

Anyway. You need to start a cold engine using glow plugs. Starter motor and glow plug draw will have lowered the battery state so that it should accept everything the alternator can send to it for a while. As soon as the engine starts, measure voltage across the battery. Then measure B+ coming outa the alternator. The difference is what's being lost in the tractor wiring, and is the reason I added a 10ga "charging wire".

As far as taking longer, that's a cop out. Many tractor users want to get cold weather jobs done as fast as possible. That by itself cuts down the amount of time to permit the battery to top up. I'd prefer mine to top up as efficiently as possible. The OE wiring - at least in the four Chinese tractors I've owned - does not permit this.

Here's two more examples;
1. measure battery voltage
2. measure buss bar voltage while the keyswitch is in the HEAT position
3. subtract the buss bar voltage from battery voltage
the difference is lost through the OE wiring, and is the reason I installed a glow plug relay
4. measure battery voltage again
5. measure input voltage (small wire) at the starter solenoid while the keyswitch is in the START position
6. subtract the input voltage from the battery voltage
the difference is lost through the OE wiring, and is the reason I installed a starter relay.

FYI, less than 9v at the solenoid input can cause the pinion gear to fall short of the ring gear

//greg//

 

[greg_g]

How much those little alternators cost? I'm guessing pretty economical price?

Nope, they're comparatively expensive. More expensive in fact, than the alternator I recently put on my Mercedes.

Before I decided on what to do with that one I mentioned above, I priced checked new OE type Chinese alternators. The little 200w version went for anywhere between $137 and $196 FOB. A 350w was in the $160 to $195 range.

//greg//

 

[jinmajm284]

Hi Greg-g:
I was just wondering how you converted a Chinese alternator to a 1-wire , and got it to bench test at 35+ amps and 14.5 volts. Could you draw a diagram for me or some really good pics.
PJ

 

[Soundguy]

Cha-ching$ wow... I thought they might be 'affordable'. Darn.. and yeah.. that's more $$ than the one i put on my wifes lincoln a couple years back..

I've seen users post prices here if the injector pumps and nozels.. and glow plugs..etc.. and hydro pumps.. and they seemed real good.. even starters... guess they like their alternators though.

Anyone ever tried a delco 10/12 SI or 130SI conversion? enough room for the 10/12? maybee for the 130.. it is a hair smaller..

As with the other fellow, would love to know about your conversion.. don't matter that it is on a chinese tractor.. I like seeing things like that.

Having never been in a chineese one.. how do they look? well built?

I'm familiar with GM and some ford alternators.. hitachi.. etc..

Soundguy

Nope, they're comparatively expensive. More expensive in fact, than the alternator I recently put on my Mercedes.

Before I decided on what to do with that one I mentioned above, I priced checked new OE type Chinese alternators. The little 200w version went for anywhere between $137 and $196 FOB. A 350w was in the $160 to $195 range.

//greg//

 

[montanaman]

I've not done it, but there should be plenty of room to put a converted to one wire Delco on there. Might need to fabricate a bracket to do it, but shouldn't be a big problem. The factory brackets aren't much to write home about anyway and building one could only make things better. On the 200 series, the bolt holding the bottom of the alternator only supports it from one side so it could be done better!

Ken

 

[greg_g]

Hi Greg-g:
I was just wondering how you converted a Chinese alternator to a 1-wire , and got it to bench test at 35+ amps and 14.5 volts. Could you draw a diagram for me or some really good pics.
PJ

No diagram necessary PJ, I simply attached a TransPo external self-exciting regulator to the back of the alternator. It's a comparatively tiny little thing, perhaps and 1"x1.5" square and less than 1/2" thick. TransPo model number is 07-014/12v-1947. Thirty five bucks. Takes ~900 tractor rpms (by my tach) to excite. There are other models that should work, but I have to wait for my TransPo catalog to arrive before I can look them up. My satellite connection doesn't agree very well with their online catalog.

Conversion is a simple matter of disconnecting the two Chinese VR leads and connecting four of the five SER leads to the four alternator posts. The fifth SER lead is idiot-light optional, I clipped it off. The only alternator wire connected to the tractor then, is B+ to the starter battery cable post.

The numbers? It is already a nominal 14v/350w alternator (25A). So getting 14.5v and 35 amps on the bench isn't much of a stretch. Of course, bench testing almost certainly presents a larger load than would typically be seen while tractor mounted.

//greg//

 

[Diamondpilot]

I have not done it but there was a post on CTOA where a guy put a 130 on his tractor. All he had to do is have a bigger pulley pressed on. If I remember right he had less than $100 in the whole thing. His starter had not failed but he was adding a winch and 4 big off-road lights and wanted the extra power.

Chris