A Tecumseh Tale

[Tractorhead 9,064]

2 hours ago, Gregor said:

I won't bore you with all the details of what I did, but I will tell you, it involved multiple plugs, 2 sets of points, and 2 condensers. The end result is, with the plug NGK BR2 LM, spinning it with my drill, I have no spark. With a NGK B4 LM, (Lawnboy plug) and a Champion H10C, I have spark at low RPM. If I spin it fast, no spark. That's where I stand. I guess I will have to wait for my new coil, points and condenser to get here, but that could take a week or more.  In the mean time I am going to investigate the possibility of putting the Kohler K161 on the 656. I have learned a lot working on this Tecumseh. The most important thing I learned is DON'T.   Get a Kohler, if you can find one.

 

I also own an 656 since this year and i love it.

if it runs in idle i can see several missing sparks, what indicates on my machine to points or even condenser.

that‘s the reason i will convert to breakerless.

 

my only challenge i had was the setup of the Carb.

- until i have found one loosen nut. It was on but the thread was defect.

A simple Washer fixed this for the moment and i was able to Setup.

 

Screw on the bowl carefully fully in and 2,5 turns back.

than idle, than Full throttle setup and you‘re done.

 

never run that Cast engines without any Airfilter or they wear very quick.

[Tractorhead 9,064]

6 minutes ago, 305 said:

And they told you that it would work with the H60 with two magnets in the flywheel?

Yes it shall ,but i will se it soon..

 

 

[Gregor 4,846]

I sure hope that breakerless system works. My motor has a charging system, and has several magnets in the flywheel. If that makes a difference.  I really believe this motor is a hodge podge of thrown together parts. It might be that it will never run correctly, and just in case it doesn't, I am workin' on it.

[Gregor 4,846]

So I discovered something on the H70.I decided to set the timing,once again, and it was fine. I wanted to see what would happen to the timing once the flywheel was on, and torqued down. I ran a wire from the point behind the flywheel to check it with my light. It changed dramatically. I also noticed the motor turned a lot harder with the flywheel on. I still had some end play in the crank, so what gives. Took the flywheel off, timing was fine. Got to looking around. The inside of the flywheel is rubbing on the coil / charging assembly. Rubbing on the laminated steel plates. I think this may be why I am getting such a screwy reading from my spark tester. What are my options? Do I get my 4 1/2 angle grinder out, and take a shade off the laminate? Is there another better option? The coil assembly rotates on an axis, using the oil seal as a hub. It is the correct seal, ordered for a Tecumseh. Any ideas anyone?  Thanks  Greg

[Tractorhead 9,064]

Sounds to me the gap between coils and flywheel is not set right.

 

check out the manual, how to setup the gap between coils and flywheel.

 

[Gregor 4,846]

The coil is under the flywheel. It's placement is set by the oil seal.

[Howie 892]

You can not change that gap on a Tecumseh. If it is too close there is a mis-match in parts somehow

I believe. The HH60 on my Lawn Ranger is a mix of parts i gathered and it all works together. You 

would have a hard time just grinding down the lamintations and getting the clearance correct in my 

opinion.

[Gregor 4,846]

Since no one old me not to, I put some masking tape on each of the points where it could contact, installed the flywheel, and spun it around. The flywheel was rubbing on 3 of the points. I filed them a bit, and then flywheel no longer hits them. I then closed the book, turned off the how-to videos, and decided to do it my way. I set the coil rotation in the center of it's travel, and adjusted the point gap to reach my timing of..080" BTDC. Point gap is now about .017 instead of .020. Put it all back together, spun it with my drill, and it fired, for a split second. I didn't get my drill of quick enough, and of course, the flywheel nut came lose, and it sheared a key. Tomorrow is another day. I will replace the key, go through it all again. Although the motor does turn over easier now, my starter still won't spin it. Maybe the starter is weak, and I can have it rebuilt, or find another one. As far as the gap in the flywheel to coil spec, I don't think you can get too close, as long as it's not rubbing on it. But I may be wrong.

[wallfish 17,023]

Your persistence, perseverance and determination with this is extraordinary!

I would've used the Tecumseh Timing Tool by now --- A BFH. Fixes the starter too

[Howie 892]

On a Tecumseh to set the timing set points to .020. Then set the piston to .080 below TDC, loosen the

bolts so you can turn the plate and turn it until the points just open and lock down. Can put a thin piece 

of paper between points and when it can be removed lock down or use an ohm meter to see when they 

open. I do think the gap is important although it can not be moved on the Tecumseh.

[Gregor 4,846]

I have a 12v test light set up to check timing. Between the 656, the K161, and this H70, I have been out here for 18 hours now. I think I'm tired.

[ebinmaine 67,717]

1 hour ago, wallfish said:

BFH

What poundage?

[Tractorhead 9,064]

As you told your Flywheel just hits on few Points makes me believe there is something other wrong.

Is it the right Flywheel for this Engine?

does it run before smoother without hitting any coils.

 

i see it after i disassebled my Engine that the Coils gonna be died by whatever reason.

So i have to rewind new Coils to bring my Charging system back in Service Again.

Here are few Pic‘s

 

 

Firstly removed the Flywheel what looks not very differently to your‘s in the Pict‘s

 

 

 

Than i found the rotten Coils.

No wonder they would induct any Voltage

 

 

I try to carefully pry them off

 

 

One coil felt totally apart while pry off

The other survived as template for the rewinding.

 

So i built a template on my 3 D Printer for a recoil 

 

 

Than i rewound few different samples with different turnings

 

 

 

 

Here are all three Coils next to the other.

the coil on the right is wound with 0.25mm and 78 windings.

They be built from an old transformer i had allready laying arround.

the best results i measured with 0.5mm Wire and 78 Windings.

This Coil delivers 19V on idle and 9A of charging shortcut Current.

 

 

Than i reinstall them with new Wirepaths.

 

I added two different Coils to see witch works the best in Voltage and in Current.

 

The new Wirepath

 

 

Secured them with a little blue Loctite middle tight.

Here on this Pict can be seen the 2 screws they keep the mounting plate.

Because of the 2 elongated holes in the groundplate a little shift in that can cause the hit on the coils to the Flywheels.

 

 

The final Wirepath 

 

 

Safed with few Straps to keep them out of moving Parts.

 

An important thing i see when i firstly remount it, the Keeway mut be in straight direction,

otherwise my flywheel begin‘s a little to tilting. I did it 2 times until it fit‘s with a „smack“ sound.

Than i cloud not wobble it. The first time it seems it doesn‘t fit snugly so i can wobble the flywheel.

 

 

After finishing that, my Engine was back in Service and also the Charging System works again.

 

Btw in this last pict, you can see the Washer below the Carb nut i mentioned, 

that gives me the ability on the thread to be reused.

And after that all, i was also able to setup the Carb basic settings.

after implement that Washer i was able to setup my Carb again

 

 

 

 

Sometimes if you stuck with things it‘s better to do a break,

after that you mostly see things you didn‘t see before.

 

Edited December 27, 2020 by Tractorhead

[Gregor 4,846]

This is my flywheel. I tried to find a casting #, but didn't see one.I did a lot of things this morning, but I won't go into detail, unless it works. It's all back together again. I decided I am going to sit down, drink a whole cup of coffee while it's still hot, and smoke a whole cigarette at one time.

[Gregor 4,846]

Spun it with my drill, it started, for a few seconds.  Popped, and quit. Sheared the key. Replaced the key, now nothing. I believe it was T Edison who once described an idiot, as someone doing the same thing over and over, and expecting different results. Sound familiar? I will talk to my small engine guy, and see if he wants to mess with it. As for me, I think I'm done. I simply don't know what else to do. Maybe there is too much play in the flywheel key for this thing to operate as it should. Now the problem is, I don't have anything to do. Think I will go shopping on line for a nice broken Kohler.

[Tractorhead 9,064]

50 minutes ago, Gregor said:

Spun it with my drill, it started, for a few seconds.  Popped, and quit. Sheared the key. Replaced the key, now nothing. I believe it was T Edison who once described an idiot, as someone doing the same thing over and over, and expecting different results. Sound familiar? I will talk to my small engine guy, and see if he wants to mess with it. As for me, I think I'm done. I simply don't know what else to do. Maybe there is too much play in the flywheel key for this thing to operate as it should. Now the problem is, I don't have anything to do. Think I will go shopping on line for a nice broken Kohler.

 

That was my reason to show you the Pict‘s.

i would give you a try to start with again with a setup you can see.

 

[wallfish 17,023]

37 minutes ago, Gregor said:

Now the problem is, I don't have anything to do. Think I will go shopping on line for a nice broken Kohler.

Not laughing at you, just the statement.

The key shearing thing indicates the taper on the flywheel may not match the shaft. Flywheel hitting the laminated coil part shows something is a miss too. I have a flywheel of unknown origin but think it's from a H70 and has all the magnets like you need for a charging system. There's a couple of damaged fins but I'll send it to you for free and even pay for the shipping if you want to give it a go. Last thing you need now is to pay for something which is exactly the same thing you already have.   

[Gregor 4,846]

I do appreciate the offer, but I couldn't do that. Some day I will run across another h70,(maybe even with a  under it ) and then possibly I can see what's going on. Kohler motors in my area seem to be pretty scarce. Lincoln is shut down until after the holidays, but I will talk to him when I can, about a complete motor, of some sort. A few years ago I gave my son a snowblower with a 5hp Tecumseh on it. It runs well. I suppose it would be bad manners to repossess it.

[Gregor 4,846]

While I am sitting here watching Fort Apache for the 12th time, I have a question for the really smart guys here. Is there some specific reason why the spark plug is not positioned directly over the piston on these 1 cylinder, 4 stroke motors. All of my little 2 cycles motors are. Checking TDC and timing would be sooooo much simpler if I didn't have to tear this motor half down to do it. I was just wondering.

[ZXT 2,401]

12 hours ago, wallfish said:

Not laughing at you, just the statement.

The key shearing thing indicates the taper on the flywheel may not match the shaft. Flywheel hitting the laminated coil part shows something is a miss too. I have a flywheel of unknown origin but think it's from a H70 and has all the magnets like you need for a charging system. There's a couple of damaged fins but I'll send it to you for free and even pay for the shipping if you want to give it a go. Last thing you need now is to pay for something which is exactly the same thing you already have.   

Hell, I'll even volunteer to pay the shipping on it. As much as I hate finnicky Tecumsehs (I grew up toying with Tecumseh's and Briggs engines, putting them together and rarely had success with making Tecumsehs run right, almost always made the Briggs run like they should) I want to see you succeed. You've put too much time, effort, and more money than it is worth ($20) to quit now. I've been on such missions in the past, just for the sake of saying "I did it!", so I understand where you're coming from. I'd gladly help out if it meant you getting it running. 

[Tractorhead 9,064]

5 hours ago, ZXT said:

Hell, I'll even volunteer to pay the shipping on it. As much as I hate finnicky Tecumsehs (I grew up toying with Tecumseh's and Briggs engines, putting them together and rarely had success with making Tecumsehs run right, almost always made the Briggs run like they should) I want to see you succeed. You've put too much time, effort, and more money than it is worth ($20) to quit now. I've been on such missions in the past, just for the sake of saying "I did it!", so I understand where you're coming from. I'd gladly help out if it meant you getting it running. 

 

Whatever you do, keep his engine until next Big Show after Covid

i jump together with ZXT in the row to help you, get this thing running.

 

[Gregor 4,846]

There is a 6.5 hp Tecumseh for sale right here in town. The seller does not mention the model #. According to Partstree the 6 and 7 hp use the same mag and flywheel. I have tried to research the 6.5. but I don't know the numbers. Now that I look again, I'm not even sure which is the 6.5 and which is the 3 hp.

https://www.facebook.com/marketplace/item/4088058611268705

[Tractorhead 9,064]

2 hours ago, Gregor said:

There is a 6.5 hp Tecumseh for sale right here in town. The seller does not mention the model #. According to Partstree the 6 and 7 hp use the same mag and flywheel. I have tried to research the 6.5. but I don't know the numbers. Now that I look again, I'm not even sure which is the 6.5 and which is the 3 hp.

https://www.facebook.com/marketplace/item/4088058611268705

 

Ask him if it runs and get a demo before buy.

That‘s the safes Way IMHO to get a running Engine.

[ebinmaine 67,717]

22 hours ago, Gregor said:

While I am sitting here watching Fort Apache for the 12th time, I have a question for the really smart guys here. Is there some specific reason why the spark plug is not positioned directly over the piston on these 1 cylinder, 4 stroke motors. All of my little 2 cycles motors are. Checking TDC and timing would be sooooo much simpler if I didn't have to tear this motor half down to do it. I was just wondering.

I'm no engine scientist but it's something to do with the flame quench. Lots of four cycle engines do it that way.

I've also heard mentioned that putting the spark plug directly above the Piston as it goes up and down can cause the plug to become fuel soaked somehow.

 

I remember reading on this website fairly recently that having the spark plug directly above the Piston is better for a race engine but having it above the exhaust valve? Is better for a worker type engine.

 

[Tuneup 1,433]

You've fought the good fight. There is someone else, maybe handy in IL, that is in the know. I had the EXACT thing happen to a 6 HP rope pull I got at 17. What was that, 1979? No youtube and no internet. It would kick once and lose the spark. Flywheel off and on, timing adjuster, etc. I even had the Simplicity cranking it with a belt for a while. Gave up after it affected my grades at school. The tech guys in the high school shop got it and gave it back perfect. None could tell me that they did anything but a basic timing alignment BUT I knew I hadn't torqued the flywheel - wanted to get it back off quickly to check again. Yeah, 17 and no former experience. That engine ran on the minibike for over a year. Never had a lick of trouble and stayed the heck away from that ignition! Touchy little bit$$es.