What did i miss????

[FELLNORTH]

goodmornin' all. here the situation, my fils 670 champ blew a big end rod bearing and needles went up the transfer..... P/C shot. thats ok this is his third champ and hes got parts.
tear it down, find a good crank, good P/C, wash it all up and reassemble... no biggie right.....
the thing wont fire. put three different coils, and 2 different flywheels on this thing last night and still no spark.....
plug is good, saw ran before the bearing went through it, unpluged the switch....
im lost!!!!!
got any ideas?
thanx in advance

 

[pioneerguy600]

goodmornin' all. here the situation, my fils 670 champ blew a big end rod bearing and needles went up the transfer..... P/C shot. thats ok this is his third champ and hes got parts.
tear it down, find a good crank, good P/C, wash it all up and reassemble... no biggie right.....
the thing wont fire. put three different coils, and 2 different flywheels on this thing last night and still no spark.....
plug is good, saw ran before the bearing went through it, unpluged the switch....
im lost!!!!!
got any ideas?
thanx in advance

Evidently all of your components you have tried are faulty, if they were good then you would have fire. Did you change both parts of the fireing mechanism? The trigger and the module, in my experience , which is limited to only a dozen or so with the two piece ign is that if there is a weak fire it is usually the module, if there is fairly good fire but the engine won`t spool up it`s the trigger. When there is no fire then try replacing one piece at a time, if the pieces are good then there will be spark. Did you check the high tension/sparkplug wire for continuence/ that electricity can travel through it.
Pioneerguy600

 

[FELLNORTH]

thanx jerry!
ill break out the ohmeter tonight.
can a flywheel go bad?

 

[Cantdog]

Is it a one piece or two piece ign? If it's one piece make sure you have a good ground on the coil. Some have a very short wire that goes to the lower mounting bolt, others have the ground made into the coil case where the mounting bolt goes through the coil. Make sure that these are clean (sanded) both on the case and the coil. Set the coil air gap to 0.012". Check the wire routing to the switch for any pinches and/or grounds. As Jerry said check the plug wire especially at the plug end connection some times they lose connection between the wire and plug connector right in the boot.


If it's two piece pretty much all the same applies except check the wiring between the pick up and the spark coil for any shorts/grounds and also check these wires for continuity with an ohm meter. Just for kicks check for continuity between the cyl and case too just to make sure the cyl is not somehow insulated from the case.
Never known a flywheel to go bad except when the magnet got loose and flew out. So if they are there and are still magnetic I can't see a problem with the flywheel.

If none of this seems to work then as Jerry said perhaps ALL your used parts are junk. This does not seem likely but stranger things have happened.

If possible replace the coil components with known working units or set them up on one of the other carcases enough to see if they show any spark perhaps?? Just thinking out loud.

 

[Fish]

Try a new spark plug.

 

[Cantdog]

I agree.....never overlook the obvious.......and the cheapest fix...even though I know you said the plug was good...I hate to be fooled by a spark plug!!

 

[Steveo_supremo]

Is it possible that You are mixing an older flywheel meant for the 2-pc ignition with a newer 1-pc coil or vice versa? I don't know if that can be done or not.

 

[PB]

Is it possible that You are mixing an older flywheel meant for the 2-pc ignition with a newer 1-pc coil or vice versa? I don't know if that can be done or not.

All good advice. The above was the first thing that came to mind but I cannot remember if there was a crankshaft change and if there was would it affect the flywheel assembly.

Now you are going to make me dig through piles of IPL's so I can figure it out.


EDIT: From my 1999 IPL it looks like there are 3 possible flywheel combinations.

 

[pioneerguy600]

I know that on more than one occasion the parts that were given to me by an owner to repair their saw was defective, they did not want to spend much to get their saw repaired and wanted to use old spare parts that they had cannibalised off other saws they owned or were given parts from other sources. These proved out to be no good but I always got the ,"they were good when I took them off or when I got them story, " well after installing and shifting everything I could think of around and they still would not work I installed a good set I keep for a spare for my saw, got spark instantly. Pulled them back out and keep them outa sight , it was really hard to convince the owners that their old parts were no good.
Pioneerguy600

 

[Steveo_supremo]

Yeah, there are definitely 3 different flywheels. Whether or not they are interchangeable, I haven't a clue.

 

[jockeydeuce]

Yeah, there are definitely 3 different flywheels. Whether or not they are interchangeable, I haven't a clue.

:agree2: Like Steve said, there are three flywheels....The early one for the two piece ignition (Key in crank) # 501 52 52-02, then another "key in crank" type for the one piece ignition # 501 72 82-02 and then the latest one has a built in aluminum key and is # 503 51 15-03....This latest one uses a different crankshaft as well. The ignition remains constant on the last two with the one piece.

Have you actually tried to fire up the saw?? Those one piece coils have some sort of "anti kick back" set-up in them and won't produce spark until at a fairly high RPM.....I just ran into that and thought I had a dud ignition until I really whipped the thing over and it fires up fine.

 

[SawGarage]

:agree2: Like Steve said, there are three flywheels....The early one for the two piece ignition (Key in crank) # 501 52 52-02, then another "key in crank" type for the one piece ignition # 501 72 82-02 and then the latest one has a built in aluminum key and is # 503 51 15-03....This latest one uses a different crankshaft as well. The ignition remains constant on the last two with the one piece.

Have you actually tried to fire up the saw?? Those one piece coils have some sort of "anti kick back" set-up in them and won't produce spark until at a fairly high RPM.....I just ran into that and thought I had a dud ignition until I really whipped the thing over and it fires up fine.

on the LATEST crank, (late 90's...) it is JUST before the change to the 371 saws... IIRC...