Grrrrrr... Tecumseh....

[JustJason]

Whoever invented the reverse face dial indicator needs to be shot.

I have this old 1970 ariens snothro that i'm fixing for a neighbor for FREE(well a case of beer... but it might as well be free). It needed a myriad of work. It's a single cylinder points based ignition system (since it's a 1 banger, and it only runs at 3500rpm, there is no reason on earth why this thing shouldn't have a simple external magneto ignition coil... but nooooooo)

So you have to set the point gap first, and then set the fixed advance on the timer base. Because this is an L head, you have to pull the head and set up a dial indicator on the piston. Find 0TDC yadda yadda. Well I have the service manual thats so old it might as well be written in 1776 by Ben Friggen Franklin himself. It's not the easiest thing to read, and the pictures are worse, and this is the first time i'm performing this procedure on this type of engine.

So anyways, the good book calls for finding 0, rotating in reverse .010 past the spec of .080 BTDC, then rotating forwards .010 to get to spec. This is done to eliminate "crankshaft play". Yeah... real precision stuff. After you set the pist to .080BTDC you need to rotate the timer base so the points just break. Sounds easy enough right?

I'm sitting here scratching my head, and my arse as to why I can't get the dang procedure to work.
I'm reading reading reading... doing doing doing. It isn't happening.
I'm going nuts.
I say to myself... either the procedure is wrong in the manual (wouldn't be the first time for things like that) or I must be missing something here.
I know how to use my dial and my meter and my feeler gauges, so i'm confident its not that.... or am I???

Then it friggen hits me.

In the manual they are using a reverse rotation dial. So .090 would be to the right of 0, and .010 would be to the left. I have a standard rotation dial. On mine .010 is to the right of 0, and .090 would be to the left.

In the manual it says after finding 0, turn the crank CCW until .090 is displayed on the dial, then turn CW until .080 is on the dial. The CCW and CW rotations were backwards for me. On top of that, to get it timed I had to go CCW until it was .010 on MY dial, then foward to .020 to get the thing timed to 80 thousands before top dead center.

Whoever invented the reverse face dial needs to be shot!!!

 

[Bifflefan]

Re: Grrrrrr... Tecumseh....

I think my neighbor has the same sno-blo. Ill tell him not to even try to work on it.

 

[windsors03cobra]

Re: Grrrrrr... Tecumseh....

Those rusty old hulks can be a real pita to work on but iron horses can really work and built to last. I think the Tecumseh snow king was probably one of the best small engines ever made, course I've never had to remove a flywheel or monkey with the points on one.

I think the Federal Gauge Co. invented that indicator.

 

[dolluper]

Re: Grrrrrr... Tecumseh....

WELL either narrow or widen the points gap to get it to fire frig the rest of the B,,,,,s.....back to basics works well

 

[JustJason]

Re: Grrrrrr... Tecumseh....

WELL either narrow or widen the points gap to get it to fire frig the rest of the B,,,,,s.....back to basics works well

nawww... doesn't quite work that way.
The plug fires when the points open. if they don't say closed long enough the condensor won't build a charge high enough to get good spark. If they stay closed to long spark duration is crap. Doing it by the book gets the correct gap, correct time, and even though there is no way to double check it on this motor, correct dwell.

 

[lowkee]

Re: Grrrrrr... Tecumseh....

Face it, Jason. Even the new tecumseh's don't run for crap. Getting the point gap perfect is putting lipstick on a hippo. Maybe the technical writers were trying to find out who actually bothered trying to be accurate with their one lungers.

 

[dolluper]

Re: Grrrrrr... Tecumseh....

what lets say 0.16 gap is called for ...well without going into rocket science you can either increase the gap or decrease the gap till it fires then fine tune on the plate come on now it isn't that hard

 

[JustJason]

Re: Grrrrrr... Tecumseh....

Even the new tecumseh's don't run for crap.

So true. This thing would run so much smoother if it was a 7HP twin instead of a 1 tube flat head torquemonster wannabee.
I do alot of small engines over the winter up here. Briggs, Kholers, If you seen 1 you've seen them all. Every tecumseh seems to be different, they all run great for 1/2 an hour before something craps out.
And don't get me started on tecumseh's governor systems... If your off by a chest hair in either bending the link rod (coathanger) or if there is by chance an actual screw, the thing goes from it's intended 3500rpms to 8 grand. And if you don't catch it in the 1/2 a second your allowed, your spitting the case to fix the weights or the spool. And what's with all the holes in the governor linkage? Between the governor arm and the carb linkage there must be 9 different holes. And you have to have the right combination or else it either doesn't make rpms, or you overspeed the thing.

And there are a few other things that are just engineered like junk on this thing.

This thing isn't designed from the ground up... it's designed from the turd down.

 

[dolluper]

Re: Grrrrrr... Tecumseh....

Hummm maybe time to think logical...nine settings keep trying till there while running 2 minute fix don't get frustrated just do it

 

[JustJason]

Re: Grrrrrr... Tecumseh....

well without going into rocket science you can either increase the gap or decrease the gap till it fires then fine tune on the plate come on now it isn't that hard

Dude... you'd have to see this motor to know what i'm talking about. It is rocket science and it is that hard.

For instance to access the points. You have to remove the rear engine cold weather shroud. To remove it is 5 bolts. 2 little guys, 1 on each side. And the other 3 go through the top of the shroud, through the head, and are 3 of the 7 head bolts.
One of those 3 bolts is also 1 of the bolts that secures the gas tank. The gas tank is 3 bolts as well. One is 1 little guy on the side too, One is a common bolt with the shroud and head, and the other one is a 4th head bolt that you must loosen to swing the tank out of the way to remove the shroud. Now you have to remove 3, but also loosen a 4th out of 7 head bolts just to get the rear shroud off.

Then you gotta pull the flywheel. Do your adjustin, put the flywheel back on, and.... and this part is optional.
1. pull the other 4 head bolts, clean off the old gasket, put on a new gasket, re-install the head, the shroud, the gas tank... and
A. Hope it all worked out the first time I adjusted it by feel.
B. It doesn't work out and I have to start all over....

And then there is always C.... I have no idea if I got it right or not because I chose as a "shortcut" not to change the head gasket and now the head leaks... and I can't excactly just "torque it down" some more because it's all aluminum... and prone to cracking.

Then there is timing, it's fixed timing, no advance. It doesn't quite say it in the book, but I did some quick math in my head and i'm thinking its fixed somewhere inbetween 18 and 20 BTDC. And like every other engine... if my timing is to low then I have no power, If I have it to high, I'm going to overspeed the motor, and could possibly have detonation issues.

I wouldn't lie to ya dude, this thing is murderous. We're talking 18th century technology here. I can't imagine the lower output ethanol helps any either. It only makes it pickier.


I had a similar tecumseh last year that was yet another neighbors, that belonged to his grandfather. It was bolted to a 1960's coleman generator. I put 4 or 5 hours into that hunk of crap getting it to run correctly. We had an ice storm last year and everyone around lost power for at least a week. That next day I find this thing sitting in my driveway with a note asking to fix it. I got it up and running and it ran all night for 12 hours straight no problems. Come moring the temp rose 20 degrees from 15 to 35. It took a dump. Fouled the plug. Got it running the next day, new plug, ran all night, warmed up the next day, still running it dumps again. The main jet is an adjustable high speed jet. You have to richen it up for cold weather, when it warmed it just 15 degrees it ran too rich and fouled plugs. You litterally had to adjust the high speed main for a 15 degree temp differential. And since its done more by ear, because adjusting the high speed main doesn't effect RPMS unless it's way out 1 way or the other, most people can not do it correctly.

 

[j_martin]

Re: Grrrrrr... Tecumseh....

Whoever invented the reverse face dial indicator needs to be shot.

I have this old 1970 ariens snothro that i'm fixing for a neighbor for FREE(well a case of beer... but it might as well be free). It needed a myriad of work. It's a single cylinder points based ignition system (since it's a 1 banger, and it only runs at 3500rpm, there is no reason on earth why this thing shouldn't have a simple external magneto ignition coil... but nooooooo)

So you have to set the point gap first, and then set the fixed advance on the timer base. Because this is an L head, you have to pull the head and set up a dial indicator on the piston. Find 0TDC yadda yadda. Well I have the service manual thats so old it might as well be written in 1776 by Ben Friggen Franklin himself. It's not the easiest thing to read, and the pictures are worse, and this is the first time i'm performing this procedure on this type of engine.

So anyways, the good book calls for finding 0, rotating in reverse .010 past the spec of .080 BTDC, then rotating forwards .010 to get to spec. This is done to eliminate "crankshaft play". Yeah... real precision stuff. After you set the pist to .080BTDC you need to rotate the timer base so the points just break. Sounds easy enough right?

I'm sitting here scratching my head, and my arse as to why I can't get the dang procedure to work.
I'm reading reading reading... doing doing doing. It isn't happening.
I'm going nuts.
I say to myself... either the procedure is wrong in the manual (wouldn't be the first time for things like that) or I must be missing something here.
I know how to use my dial and my meter and my feeler gauges, so i'm confident its not that.... or am I???

Then it friggen hits me.

In the manual they are using a reverse rotation dial. So .090 would be to the right of 0, and .010 would be to the left. I have a standard rotation dial. On mine .010 is to the right of 0, and .090 would be to the left.

In the manual it says after finding 0, turn the crank CCW until .090 is displayed on the dial, then turn CW until .080 is on the dial. The CCW and CW rotations were backwards for me. On top of that, to get it timed I had to go CCW until it was .010 on MY dial, then foward to .020 to get the thing timed to 80 thousands before top dead center.

Whoever invented the reverse face dial needs to be shot!!!

What is the big deal. You set the gauge for 0, then rotate the engine in reverse about .090". If it lands on .010, then move back to .020, if it lands on .090, then move to .080.

On a fast rise crank cam, point gap doesn't change timing much, and for spark potential point gap is critical.

I agree that having to pull the head for timing adjustment is pretty sophomoric engineering.

Tecumseh felt forced to go to chinese engines to compete. The mush metal crap didn't last long. Long story short, they be in big trouble if they are in fact still in business. I'm sure there's a lot of negative business climate factors in there also.

 

[jay_merrill]

Re: Grrrrrr... Tecumseh....

If the flywheel has only one magnet, you might be able to use one of these ....


http://buffalosmallengine.com/index...ducts_id=971&zenid=vfonkgd5h1ekq1k15uc9q2d984

I've had a set of them in a 6hp Johnson outboard since early 2006 and they work just fine.



???

 

[JustJason]

Re: Grrrrrr... Tecumseh....

Its all back together and running great.

I went to swap the plug and when I pulled it half the threads came with it... Damm thing

Oh well... it'll run until the plug blows out I guess. It either will or it won't.

 

[windsors03cobra]

Re: Grrrrrr... Tecumseh....

I guess their engines sucked and thats why they are out of business now.
Hope those china made Honda clones work out for MTD.......
I've gotta assume the new snow king is a Briggs & Scrapiron.

 

[cougar1985]

Re: Grrrrrr... Tecumseh....

If the flywheel has only one magnet, you might be able to use one of these ....


http://buffalosmallengine.com/index...ducts_id=971&zenid=vfonkgd5h1ekq1k15uc9q2d984

I've had a set of them in a 6hp Johnson outboard since early 2006 and they work just fine.



???

Threw something similar in a bobcat snowthower circa 510 .b.c. !lol!one pull wonder now!

 

[Lone Duck]

Re: Grrrrrr... Tecumseh....

Threw something similar in a bobcat snowthower circa 510 .b.c. !lol!one pull wonder now!

Yup! When I had my small en shop. I replaced a lot of old point systems with them. Customers thought I was god . Never had a complaint . Can't remember now, but I think the ones I was getting had a different name.

 

[dolluper]

Re: Grrrrrr... Tecumseh....

Princess Auto still sells them cheap in the surplus secton you have one outside of Van been there..............................hack

Yup! When I had my small en shop. I replaced a lot of old point systems with them. Customers thought I was god . Never had a complaint . Can't remember now, but I think the ones I was getting had a different name.