Thoroughly stumped at the moment SPARKLESS

[harleysportster]

Loyd, please list all the ohm readings that you measured.
Low speed winding
high speed winding

[luvzvintage]

hi!

all ohm readings were within a point or two of the following except the lighting coil as i mentioned

i will however do a repeat check of all my readings

thx

Lloyd N




http://www.hewtechelectronics.com/image ... WIRING.pdf



Here are pictures showing the connector block of the stator tested with a ohm meter
http://home.comcast.net/~psshd/CDI/lowspeed2.jpg
http://home.comcast.net/~psshd/CDI/highspeedcoil1.jpg
http://home.comcast.net/~psshd/CDI/magtriggercoil1.jpg
http://home.comcast.net/~psshd/CDI/ptotriggercoil1.jpg
To test the lighting coil, unplug the main wiring harness from the sled to the engine and test the 2 top slots.
http://home.comcast.net/~psshd/CDI/lightingcoil1.jpg[/URL]
You can test the external ignition coils by using a ohm meter.
To test the coil, measure the ohms between the primary stud terminal and the high voltage spark lead and between the high voltage spark lead and the small grounding wire. I believe 100-300 ohms is an acceptable range. Also test between
the lead to the ground connection to the primary terminal of the coil...it would be from .1 to . 5 ohns.
I have NOS coils that measure out at around 150 ohms. (Picture soon)'76 440 cyclone
'76 440 liquifire
'78 440 Cyclone
'75 JDX8 (sold to a member here)
'78 Liquifire
'80 Liquifire
http://home.comcast.net/~psshd/site/
harleysportster

Posts: 2595
Joined: Thu Jul 14, 2005 12:00 am
Location: Southeast Pa.

[harleysportster]

If the stator ohms checked out except for the lighting coil, the ignition should work but no lights. They are 2 separate circuits.
With the stator ignition windings checking out ok, it leaves the cdi box at fault.
When you are checking for spark, do you have all the switches unplugged and the black kill wire of the cdi un-hooked?

[luvzvintage]

i unplugged the main harness (white square plug) which isolates the ign and kill switches but, no, i didn't disconnect the black wire to ground from the CDI.
My lights appear to be working fine.

[lwb140]

I'm sure you checked spark with the engine harness unplugged to eliminate the kill switches and sled wiring , also check to make sure your ground straps a are connected as well , you are down to ignition coils hope this helps. Wade

[harleysportster]

i unplugged the main harness (white square plug) which isolates the ign and kill switches but, no, i didn't disconnect the black wire to ground from the CDI.
My lights appear to be working fine.

There are 2 black wires, one with a stud ring terminal for grounding and the other originally plugged inside of the square connector. The black wire in the square connector is the kill wire. Most but not all '76 Cyclones and Liquifires had this black wire removed by the dealer and then it was connected directly to the white ignition wire from the dash panel. If you have the dealer modification, then unhook the wires and check for spark.
As was mentioned earlier, check all the ground wires, remove them and clean any rust.
Curious, what brand was the aftermarket cdi?

[luvzvintage]

$_35.jpg (6.74 KiB) Viewed 711 times

John Deere Cyclone 340 & 440, 1976 1977 1978, CDI Box - AM53644



--------------------------------------------------------------------------------



New CDI Box for John Deere Cyclone 340 & 440

Fits 1976, 1977, 1978 models

Replaces OEM #: AM53644

[luvzvintage]

well, i redid the ohms checks and all checked out excellent! I removed the main harness receptacle thats attached to the engine with 2 small screws and found one black wire blade backed out a little. I popped it back in and just for the heck of it checked for spark...i got spark back! What sense would this make, a blade/wire backed out of its place in a plastic holder!?

I put the plugs back in expecting the sled to start rt up and it wont fire. Best it does is pop back thru the carb. seems i've got excess fuel as applying choke increases carb back-pop. And i've got raw fuel leaking out of the exhaust manifold/muffler joint. Pouring fuel into the cylinders also didn't cause the engine to fire. Repeated checks for spark are good adn i tried multiple fresh/dry plugs to no avail!

Is my crankcase badly flooded with fuel when i pulled it over so often when i had no spark??

[harleysportster]

It is not uncommon for the spade terminals to pop out of place. Check out the wires in the connector by tugging on them. It sounds like the crankcase is flooded.

Sent from my XT1080 using Tapatalk

[luvzvintage]

whats the best way to clear the crankcase? Would it help to pull off the impulse line and then pull the engine over a couple dozen times?

[harleysportster]

turn off ignition, remove the spark plugs and pull engine over many, many times.

[luvzvintage]

OK I'll try that. I pulled the impulse line from the pump this morning....no fuel in it. Cranked the engine over and only a drop or 3 of fuel came out. Pulled the plugs and left the impulse line disconnected. Worked nites, so gonna take a sleep and pull er over a couple dozen times later this aft.

[luvzvintage]

Finally gave up on trying to start this thing. Decided to pull the engine and do a "rebuild"...gaskets and seals and generally clean everything up. The crankcase had no fuel in it. I'm now starting to button the engine back up and have been wondering if perhaps the running difficulties i've had with this sled continually are due to incorrect carb jetting. I believe the 340/5 engine didn't come factory with a Mikuni? Mine is running what i believe is the original 76 Cyclone 340/22 Mikuni carb with a 270 main jet. Anyone have Mikuni carb specs for a 340/5 conversion to Mikuni carb?

[luvzvintage]

wrong....just checked the carb...its got a 350 main jet

[400brian]

If you have a 340/5 engine ( are you sure that's what it is?). The /22 Cyclone engine would be reed inducted, which means the intake manifold is on the crankcase. A /5 would be piston ported, which puts the intake on the jugs.

Cyclone /22s were jetted huge. For a 340/5 piston ported engine, I think you will find something between 210 -220 to be more to its liking. However, on start-up, ( slide closed ) only the pilot jet is metering fuel. What have you got in there? I'm thinking around a 20 or 25 will work. The choke ( enrichener ) has to be adjusted correctly as well.

Several guys have done this. I messed with the same set up you are talking about for a time, then switched it out for a Walbro so I could run the airbox and quiet the thing down a bit ( this was on a 340/5 on a '74 midmount ).