070 flywheel woes

[harrygrey382]

I've started pulling my 070 down now. First thing to tackle was the flywheel - the standard pullar I have (038,056,041 etc.) doesn't fit. Made one up out of some angle iron, tube and a bolt. Worked good.

OK, so here it tunrs bad - the flywheel is rooted. The central spigot that holds it on the crankshaft is loose, meaning variable timing! This means I need a new flywheel. I'm guessing already new OEM is going to be extremely expensive, and heavn't even looked. Baileys has them for $130, but lists 1106 400 1206. My 070,090 and onctra IPLs list only 1106 400 1202. What's the difference? Will a 1206 work with my starter cup and points?

And lastly, most importantly, does anyone know of or have a spare flywheel?!

 

[striperswaper]

aye mate not sure of your terminology
rooted?
central spigot?

are you trying to say that you have a sloppy or worn keyway?

try to enlighten the coffee drinkers of the tea drinkers terminology

 

[harrygrey382]

aye mate not sure of your terminology
rooted?
central spigot?

are you trying to say that you have a sloppy or worn keyway?

try to enlighten the coffee drinkers of the tea drinkers terminology

lol, rooted isn't uk speak, it's aussie... root = fu*k

by central spigot, I mean the female taper, which the crank shaft binds too. The flywheel is permenantly attached to it and this is what holds the flywheel on. Also, it has the cam for the points. See second pic down. Mine is loose, meaning timing will never be correct. I could weld it - but I would damage the temper on the taper (maybe not so bad?) But worse, I'd have to find the crroect rotation to make sure the magnets met up with the cam at the right timing...

Although, how close would I need to be? Could I eyeball one and weld it up, or could someone measure theirs for me? How important is the temper of the taper?

 

[striperswaper]

ahh, I see said the blind man looks like you are rooted

seriously that looks like a machined center that is pressed into a stamped
flywheel
is the machined part able to rotate 360 or just a few degrees loose?
maybe you can unroot this little b#st#rd

 

[harrygrey382]

ahh, I see said the blind man looks like you are rooted

seriously that looks like a machined center that is pressed into a stamped
flywheel
is the machined part able to rotate 360 or just a few degrees loose?
maybe you can unroot this little b#st#rd

lol - rooting is very rarely reversable though...
Yep is stamped in, not sure if it was pressed to start with though. It can only turn a few degrees. What do you think about welding it and the taper's temper?

 

[striperswaper]

not sure what the heat would do to the magnets, maybe somebody could comment?
think ite worth trying reallying cleaning the interface, injecting super loctite/epoxy, then center punching the flywheel into the machined hub?

 

[harrygrey382]

not sure what the heat would do to the magnets, maybe somebody could comment?
think ite worth trying reallying cleaning the interface, injecting super loctite/epoxy, then center punching the flywheel into the machined hub?

Well I'd do small, almost spot welds, and let it cool/forced cool (water) it between each to stop it all getting hot, and I reckon I could keep the magnet damage down. Thing is I can't really clean in there - it won't come apart. And there's no space to inject glues etc.. Centre punching's not a bad idea though.

Anyone else know of a second hand flywheel, or a source for one? Or the difference between the 1206 and 1202 flywheel?

 

[striperswaper]

maybe try letting brake cleaner flow through the interface?
a hardening loctite might flow enough rather than epoxy
center punch it home
worth a try?

 

[harrygrey382]

well finally got some time fore this baby - welded up the flywheel which went well I think. It didn't get too hot and I quenched it after each pair of opposite spots. Just waiting for the dishwasher to be free now

 

[thomas72]

You might want to have it balanced. Out of balance means more vibes which leads to bad main bearings and saw parts on the ground where ever you cut.

 

[harrygrey382]

You might want to have it balanced. Out of balance means more vibes which leads to bad main bearings and saw parts on the ground where ever you cut.

reckon I'll run it first - if it feels ok I'll leave it. If it feels like somthing's vibrating too much I'll get it balanced. I've heard of people doing this before, and never heard a mention of balancing. Perhaps Roland can shed light. I also think there are other things that could contribute more to vibes than some roughly equally placed and sized spot welds that are almost at the centre of rotation.

 

[Dibbs]

I've started pulling my 070 down now. First thing to tackle was the flywheel - the standard pullar I have (038,056,041 etc.) doesn't fit. Made one up out of some angle iron, tube and a bolt. Worked good.

Now where did I see that idea before?!

Anyway,to the important stuff, rooted means stuck.

Did you get TDC on the crank and flywheel housing before you welded it up?
If not then there is a way to get your new TDC position which is needed to set points.

1. Attach the flywheel again and find TDC through the sparkplug hole, I'm sure you know how!

2. On your crackcase you will find there is a surround where your flywheel fits into, at the top of this you will find a small mark where there is no paint, this is your TDC point for lineing up your flywheel at it's TDC mark.
The two marks may not line up anymore but your cam will be in the correct TDC position for setting the points.

3. Scribe a mark in your flywheel in line with the TDC mark on your crankcase, this is your new TDC mark on your flywheel for setting your points.

Or, just fit electronic ignition and have done with it!
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=380138103069

(Nice use for old jeans by the way!)

 

[eyolf]

AS long as the welding holds and the balance isn't objectionable, I think you'll be fine.

If, as you say, the timing between the central core and the magnets has gotten out of sync, the aftermarket CDI thing might not work. As the fields build, then just begin to fall in the primary coil, the capacitor (and sometimes a transistor) senses the change and the capacitor dumps, causing the spark. Timing is dependent only on the magnets.

In a points system, the absolute timing of the magnets is important only in that you want to open the points during a falling field for strongest spark. A degree or two advanced or retarded is less important, because it's the opening of the points that triggers the condensor to dump. Since it looks like your flywheel's central core (the loose part) is also the point cam, your ignition timing wasnt affected...so long as the magnet portion remained reasonably close.

I imagine it was noisy, though. I can believe it would also have eventually ruined a number of other components. Also, if it was loose enough to rotate much more than 10-15 degrees either way, it wouldn't have ran well at all...as the rotating assy slowed near TDC compressing the fuel-air mix, the flywheel would have raced ahead far enough that the field in the primary side of the coil was becoming too weak for a good spark.

 

[harrygrey382]

Now where did I see that idea before?!

Anyway,to the important stuff, rooted means stuck.

Did you get TDC on the crank and flywheel housing before you welded it up?
If not then there is a way to get your new TDC position which is needed to set points.

1. Attach the flywheel again and find TDC through the sparkplug hole, I'm sure you know how!

2. On your crackcase you will find there is a surround where your flywheel fits into, at the top of this you will find a small mark where there is no paint, this is your TDC point for lineing up your flywheel at it's TDC mark.
The two marks may not line up anymore but your cam will be in the correct TDC position for setting the points.

3. Scribe a mark in your flywheel in line with the TDC mark on your crankcase, this is your new TDC mark on your flywheel for setting your points.

Or, just fit electronic ignition and have done with it!
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=380138103069

(Nice use for old jeans by the way!)

yep - good tip on the puller!
I didn't get TDC on flwheel. I made a mark on the case and point mounting plate to get original timing. Although maybe for future ease I should make a TDC mark. That electronic module is very cheap, I'm tempted - especially if the points don't come right fast.
Yeah I've had a sudden large scale jeans death recently, they all go at once! Gone over to wrangler 13MwZ no though, so houldn't have any wareouts for a while...

AS long as the welding holds and the balance isn't objectionable, I think you'll be fine.

If, as you say, the timing between the central core and the magnets has gotten out of sync, the aftermarket CDI thing might not work. As the fields build, then just begin to fall in the primary coil, the capacitor (and sometimes a transistor) senses the change and the capacitor dumps, causing the spark. Timing is dependent only on the magnets.

In a points system, the absolute timing of the magnets is important only in that you want to open the points during a falling field for strongest spark. A degree or two advanced or retarded is less important, because it's the opening of the points that triggers the condensor to dump. Since it looks like your flywheel's central core (the loose part) is also the point cam, your ignition timing wasnt affected...so long as the magnet portion remained reasonably close.

I imagine it was noisy, though. I can believe it would also have eventually ruined a number of other components. Also, if it was loose enough to rotate much more than 10-15 degrees either way, it wouldn't have ran well at all...as the rotating assy slowed near TDC compressing the fuel-air mix, the flywheel would have raced ahead far enough that the field in the primary side of the coil was becoming too weak for a good spark.

Yeah I as kind of hoping that much change isn't that much of an issue. There was about a degree of play in total, and I put it in the centre, so it should be out by less. I never ran it before, tried to pull it for compression and the starter wouldn't engage - it was the loose starter cup. I bet it was noisy!

 

[harrygrey382]

OK, been away for a while, well call it busy. See there's a bit of current agro in fact...

But now winter's coming (fast...) should have a bit more time. I've started putting this 070 back together and have hit a snag. No spark...
Got the timing right, set the point gap right, but put a plug in and rest it on the jug and no fire. This is a good plug. Put a screw driver in the plug socket and touch it to the jug, get a VERY weak spark. Tried closing the plug gap, nothing.

The HT lead had a nick down the the core out, I put some heat shrink on it, but could it still be a problem? I've got some new wire so will test it soon. A stihl tech said clean the magnets up (points are clean), could this help? Could a condenser/ bad timing be the problem? Last option is a bad coil right?

 

[Rookie1]

Did it have spark before you took it apart? If so maybe something you did. If it didnt have spark I would say condenser. Just because of the 031s Ive messed with.

 

[harrygrey382]

Did it have spark before you took it apart? If so maybe something you did. If it didnt have spark I would say condenser. Just because of the 031s Ive messed with.

Well it was sold as a non runner, but I didn't try sparking as the loose flywheel and starter cup made me do repairs first... I can't see how anything I did would have stoped sparking. Do magnets need to be clean? I didn't know a bad condesner would stop sparking. Haven't had time to try the new lead yet, but will do that ASAP

 

[tdi-rick]

If the condenser is totally shorted to earth, that'll obviously stop any spark.

You could check by seeing if their is a short to the can from the condenser wire with a meter, ideally a megger but a multimeter would do.
A rough coil check is to see if you have a circuit through the primary and secondary coils with a multimeter and measure their resistance.

Mate, you would have been Wallaby Ted's brother if the missus had've caught you using the dishwasher

 

[Rookie1]

The magnets are still magnets even if they are dirty or rusty.I would sand of any big flakes or scale so you can get an accurate air gap setting. Heat can weaken magnets but your little welds dont look like they would have hurt them.I have to look for it but there is some instructions on how to check with multimeter.

 

[harrygrey382]

If the condenser is totally shorted to earth, that'll obviously stop any spark.

You could check by seeing if their is a short to the can from the condenser wire with a meter, ideally a megger but a multimeter would do.
A rough coil check is to see if you have a circuit through the primary and secondary coils with a multimeter and measure their resistance.

Mate, you would have been Wallaby Ted's brother if the missus had've caught you using the dishwasher

ok, I'll check these out. Just need to sort my multmeter out first - it reads a negative resistance when touching... But still works for short circuit finding. But if it is sparking with a screwdriver in the HT lead touching the jug this would rule the shorting condenser out right?
As it happens - we have an agreement on the dishwasher! I just have to run it empty with a tablet afterwards, then it's no dramas!

The magnets are still magnets even if they are dirty or rusty.I would sand of any big flakes or scale so you can get an accurate air gap setting. Heat can weaken magnets but your little welds dont look like they would have hurt them.I have to look for it but there is some instructions on how to check with multimeter.

That's kinda what I thought. There is surface rust, but no flakes. They didn't get hot - I was very careful with welding. Only small spots, and quenched it every opposing pair of welds.
If you found those instructions, that'd be excellent