mid 50s to late 60s jd350 crawler

Post by **Lavoy** » Fri Jul 28, 2006 10:23 am

Do you know for sure that you have good hot uninterreupted power to the coil? If the wire or solenoid is bad, you may have good power when cranking, but loose it when the solenoid is not engaged. I know you said you ran a jumper wire, but you also said you blew the resistor, not sure what you mean by that. If you are running a jumper wire, there should not have been a resistor in it anywhere.
Have you replaced the solenoid, or still running the old one?
lavoy

lastchancegarage · Post by **lastchancegarage** » Fri Jul 28, 2006 3:39 pm

Keith,
You can go ahead and pull the dist but if you don't run the timing check, you won't know which way you need to go to reposition the teeth. Just put a small pencil mark on the dist base where the #1 wire goes and set #1 piston to TDC on compression stroke. From everything you've said, I'm thinking it might be past the mark. At least, if nothing else, you'll be set up to put the distributor back in using the mark on dist base. Also, I'd set at least 1 1/2 turns out on the idle to start. Keep at it. We're all waiting to see what the gremlin is.

Scott

Post by **Lavoy** » Fri Jul 28, 2006 4:55 pm

One thing I just thought of, when you get it running on the starter, turn the dist by hand one way or the other, and you will find out real quick if it is the timing.
I have never had the dist out of a 350, but if it is like the two cylinder Dubuques, there is only one position, it is not like a Chevy V8.
Lavoy

keith boucher · Post by **keith boucher** » Sat Jul 29, 2006 6:22 am

Update!!! Like i had mentioned. got the crawler home. Now I can hear with my own ears whats going on. looked at it yesterday. one thing came to mind. one of you guys mentioned that the solenoid could act as a resister. my father-in-law had mentioned that the old harness did not have a resistor in it. i jumped the resistor and what do you know. the monster fired up. now it is running really rough and smoking but i think that it is just time and carb adjustment from here on. also the oil so full of gasoline that i did not run it very long. my cylinders are getting washed up pretty bad. we will change the oil today and adjust everything and i am pretty confident we will have this thing running. i will keep everyone posted. thanks again. ps i will send pictures. this thing looks like the day it was bought. all new paint and decals.

Post by **Lavoy** » Sat Jul 29, 2006 8:01 am

Yes, on GM vehicles for one, the solenoid acts as the resistor. If I get a chance today, I will try and look at my 350, but I still don't think that they have an external resistor on them. Sounds to me like in the past, someone may have modified your crawler, but that is no suprise, I have seen way worse modifications than that.
Lavoy

keith boucher · Post by **keith boucher** » Mon Aug 07, 2006 10:03 am

Heres where we are now. Wed. we had a mechanic who has worked these old gas jds his whole life come over and give a hand diagnosing this beast. Well 6 hrs later we still had no answer. We have compression, we have fire, we have fuel, we are timed correctly. I know, this thing should be running. We also changed out the fuel, to make sure the gas was good. still, just smoke out of the pipe but it won't run. The mechanic left in a confused state, but later called and had us order a new coil. Now we have replace the coil, but with all the confusion with the wiring and cranking on the engine, he feels we may have done some damage. This coil has a built in resistor and our new wiring harness also had a resistor. He feels we only need the one in the coil and that maybe that one has been damaged while we were doing all of oul trial wiring. Could be. We should have the coil today. I'll keep everyone posted.

Post by **Lavoy** » Mon Aug 07, 2006 11:13 am

On July 29 you said you had jumped the resistor and had it running, what happened?
Lavoy

keith boucher · Post by **keith boucher** » Mon Aug 07, 2006 11:43 am

I did. But it ran for 5 mins, and i shut it off because i new that the oil was really soaked in gasoline and i didn't want to damage the cylinders. we changed the oil and tried to restart it, with no luck. like i said, its hit or miss which the mechanic feels can be attributed to a coil that shorts out after it is warmed up. the day he came over, it was in the 90 outside and we were in direct sunlight. i dont know if that is enough to make a damaged coil not work or not.

Post by **Lavoy** » Mon Aug 07, 2006 11:59 am

I would not use a resisted coil, not with a wiring harness that has a resistor in it.
Lavoy

keith boucher · Post by **keith boucher** » Mon Aug 07, 2006 1:49 pm

is there an advantage to using the resistor that is in the harness as opposed to the resisted coil. If the harness came with a resistor in line, do we have the wrong coil?

Post by **Lavoy** » Mon Aug 07, 2006 2:24 pm

No advantage one way or the other, but if the harness has a resistor in it, then it is designed to work with a non-resisted coil.
Just a thought, but if you have been cranking it that much, have you flooded it enough to wash the oil off of the cylinder walls? Run a compression check again and see what you get. Also try changing plugs again, and make sure you have copper core wires, not carbon core. Not a bid deal, but every but helps.
Have you checked the static timing with a trouble light?
lavoy

keith boucher · Post by **keith boucher** » Mon Aug 07, 2006 5:05 pm

now here is one for you. we just installed a new coil on the crawler. this thing fired right up and ran. it ran better than ever. we used it for about two hours. everything was going great then it just died like someone shut the key off. now apparently the coil was bad. do you think we just burned out the new coil. it just turns and turns without starting. there is still fire going to the plugs. if it is the coil again, what is burning it out. we dont mind replacing it, we just want to find out what is burning it out. again, the coil says right on it that it does not need an outside resistor. help......

Post by **Lavoy** » Mon Aug 07, 2006 6:05 pm

Resistor has no effect on the coil as such, its purpose is to reduce the voltage at the points to reduce arcing and extend service life, so that should not be the problem with the coil.
When it quit, did you still have good voltage to the coil, measured with a digital voltmeter? Is the coil wired correctly? I think backwards can contribute to the coil getting hot, and it yields a poorer spark.
What is the system voltage when the engine is running? Just a wild hair, but if the regulator is bad, might be high voltage.
Lavoy

keith boucher · Post by **keith boucher** » Mon Aug 07, 2006 6:51 pm

but what im saying is, if we somehow burned the internal resistor in the coil, can that happen by having a short somewhere. this machine has a 12 battery yet has a 6 volt coil. is that right or is this a rig job.

Post by **Lavoy** » Mon Aug 07, 2006 8:27 pm

No, machine should have a 12 volt coil, if you have been pushing 12 volts into it a 6 volt coil, it could have easily ruined the coil.
Do you have a 350 parts or service manual?
lavoy

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mid 50s to late 60s jd350 crawler

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