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finnaly workin on the suburban...have some questions

2227 Views 22 Replies 6 Participants Last post by  Tractor-Holic
im finnaly gettin around to workin on the suburban, you might remember me askin bout it a while back but i had to put it off while i built my garage.
Im just going to start from scratch:

I got the tractor from a neighbor, Its a 1965 sears suburban 10. Model 917.60646. Tecumseh cast iron hh100 engine.

He had started to dissasemble it for some reason, so i put everythin i could back together.

Then i started the engine, it was reluctant,but it started and ran good with some tuning. At this stage the tractor wasnt moving.

Next i put the clutch together, its still not right but it worked for puttin around the yard.

For the first few days it ran great drivin around the yard. Then about the 4th day it wouldnt start.
It would start after 5 minutes of cranking over and lots of starting fluid. Then it would run for a few minutes then die. no sputtering, just cuts out. After that it wouldnt start till the next day.

Ive gone through and cleaned the carb and fuel system, cleaned all electrical connections, still nothing.

when it first gave me problems, there was always a spark. now, a year of sittin around and there is no spark.

Im really stumped, but i want to get it runnin.

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No spark? Maybe the points need cleaning/resetting? Coil could have gone kaput..
You didn't mention cleaning the points,ot replacing them,and the condensor..I'd try cleaning them GOOD first,it may take filing them or using a wire wheel on them to get ALL the corrosion off them..then try again,if it has spark then,you might get away with the old condensor--they do dry up and fail after decades though,so try a new one before condemming the coil,which can also die of "old age" sometimes..

Yours should have points under a small cover on the crank pulley side of the engine that has two screws holding it on,towards the front of the tractor..the condenser is mounted on the coil for some stupid reason,which is located under the blower housing above the flywheel..I guess some sadistic "engineer" at Tecumseh thought we'd enjoy removing the starter/generator belt,pulley,and blower housing just to SEE the condensor!...

I may "relocate" mine if it fails someday,there is no reason it couldn't be mounted on one of the screws that hold the cover over the points.IMO--..if I dont just convert it to a car coil & condenser instead that second Suburban has solid state ignition,whichk I pray never fails..if it does I might as well just buy a Kohler 12 HP and swap it on,seeing that one smokes a bit and its probably seen better days,and wont cost much more than a replacement SSI coil for it..
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I cleaned the points. How do I reset them?
I just turn the motor by hand,watch them and ensure they are opening and closing,and then set them to .020 at the point where they open the widest,you can watch the little push rod and tell when it starts going back in..I'm not sure in .020 is the correct spec for a HH Tecumseh,but it works for my HH120's and all the others I've fooled with..

Even if the points wren't set perfect,it should run at least..I think your condensor might be crapping out,but try the points first and see if that helps any..mine would ALMOST start,but not run when I first got it,after I closed the points up some it fired right off,someone set them at more like .030 than .020!..
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I just turn the motor by hand,watch them and ensure they are opening and closing,and then set them to .020 at the point where they open the widest,you can watch the little push rod and tell when it starts going back in..I'm not sure in .020 is the correct spec for a HH Tecumseh,but it works for my HH120's and all the others I've fooled with...

I'm cleanin the points tommorrow, but I'm confused about what tractor holic said about push rods opening and closing? What does that mean? I'm cleaning the points that look the same as they do on all them small engines. Am I missing somthing?

Also, does this engine have an ssi?

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If you have the original HH100 10 HP cast iron engine from 1965 ,it should have points located where I stated in my other post..they are operated by a small pushrod or pin that dissapears into the block,thats operated by a lobe on the camshaft..spin the engine by hand and watch closely,and you'll see it extend and retract to open and close the points..spin the engine till they open the widest,then adjust them..

Solid State Ignition (SSI) on the HH Tecumsehs I think started in late 1967,or 1968..I have a '67 Suburban 12 with points,and a near twin 68 model ,that has SSI,as far as I know the engines on both are original,but I've never looked up the numbers on either to verify that for sure..
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What part of the engine would these points be on? I removed shroud that covers the flywheel, and on the flywheel is a magnet that runs over what I think is called the coil. It's the same setup that's on most small engines today.
It's a magneto. Maybe this isn't the original engine?
Read the second paragraph of post #3 in this thread again!!..I told you where the points will be if it has any there...( By "crank pulley side of the engine I meant where the BELTS go on,NOT the flywheel side!)..

if there is no points there,its either a later engine with solid state ignition,or maybe its not a cast iron HH Tecumseh,it could have an aluminum block newer one or even a Briggs & Stratton someone put on it maybe??..
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How about a photo to help figure out what you have ?
Today i turned it over trying to check for spark and didnt see one, i held my hand on the lead while i was cranking and sure enough, it sparked. it was a constant spark, but a little week. It wont make the plug spark ( new plug) and i have to almost touch the lead to ground before it does anything.

So im thinkin the problem is weak spark.
What could help that?

Ive been busy today, so i havnt cleaned the points on the magneto yet, Ill update when i clean them.

I also took off a cover down low on the pulley side of the engine, in the pics. I dont know what this thing is but it has one wire leading to ground. Is this the points you were talkin about? It doesnt move at all when im cranking over, but maybe it does at high rpm? Its very clean...


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i couldnt figure out how to make the pics bigger. heres more...


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OK,you found the points,in the upper left photo!..try cleaning them good wuth something,I usually remove them and put them against the wire wheel on my bench grinder or use a wire wheel in a dremel tool to clean them--sandpaper or emery cloth works ,but leaves grit behind and roughens them up,leading to early pitting and failure again..some guys use a point file,or an oilstone..I blast them off with carb or brake cleaner after to get any film of oil or dirt off ,and ensure both contacts meet squarely with each other,its important they make good,full contact to get a good spark..

If this fails to improve the spark after installing them and gapping them,the condenser is next to be suspect..replacing it is a pain,but they dont cost a great deal,and are cheaper than the ignition coil is..either or both can cause weak spark try replacing the condensor first..

One thing you may want to try first after cleaning and adjusting the points,is to dissconnect the wire coming from the ignition switch that goes to a stud on the blower housing,and connects to the wire going to the points and condensor..leave the wires to the condensor and points connected,only remove the one going to the ignition switch..(this is the "kill" wire that shuts the engine off)..if the spark is better with that wire off it could be the kill wire is grounding out somewhere due to chafed insulation (possible!) or maybe the ignition switch is faulty.(doubtfull)..
I bet cleaning the points gives you good may help some to sandpaper all the rust off the flywheel magnets too,if you decide to take the blower housing only takes a slight amount of corrosion on the points to kill or reduce the spark a lot..
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I finally cleaned the points today, and it of course had problems.

The everything had very light surface rust. I cleaned the magnet on the flywheel. When I took the coil of to clean, the spark plug lead fell out. I cleaned it up anyways and jammed the wire back in.

I put it all back together and i'm gettng the same result, very weak spark.

I'm assuming the condensors gone bad?

Can you enlighten me on a few thngs?

1. What exactly is pitting. The magnet has small pits in it, is that it? said that replacing the condensor is a pain. Is the condensor the little white cylinder attached to the coil? That looks easy enough...

3. You said to sandpaper all the rust off the flywheel magnets if I take the blower housing off. There's more than one? I only saw one. And I have to take the blower housing off to get to anything... I'm a bit confused...

Now that I read your post again I realized I didn't take the ground wire from the ignition switch off, I'll try that tommorrow.

Thanks for the help so far...
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Your coil is probably scrap if the plug wire came out of it,most of them had the coil wire molded right into the coil itself..not every coil is made that way,some had a lug you could wrap the wire around and solder on or had a socket like a car coil has for the wire..

I bet yours got pulled out somehow,or simply deteriorated from old could put a car coil on it instead,..

I posted a thread on the "Small engine repair" forum awhile back to "Mad Jack" who was having coil troubles with a Suburban much like yours,so rather than re-hash it here I suggest you search for that thread,if you choose to go that'll need a car type coil,possibly a ballast resistor,depending on what coil you get,and a toggle switch to turn that coil off and on,since your original ignition switch was designed for a magneto type coil that needs to be grounded to shut off the engine,where as a car coil needs the 12V source interupted to "kill" the might have "fun" trying to find an original coil for that engine,they aren't as scarce as a SSI coil,but probably aren't cheap either..
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Oh yeah,by "Pitting" I meant ON the point contacts themselves..there might be only one magnet on your flywheel,if it has a starter/generator,and I think yours would..sanding them clean cant hurt,but its not a usual cause of weak spark..if they lose their magnetism it can cause weak spark,but its rare for that to happen..

Replacing the condensor is a "pain" only because you have to take off the blower housing to get at it..that means taking the belt gaurd off the starter/generator,the belt,three head bolts,the throttle cable clamp,and one of the blower housings bolts on the generator side sucks to get at!'ll have to take the starter pulley off too..not a HUGE deal,but when you realize they could have simply put the condensor right next to the points under the same cover,it makes you wonder WHY the heck didn't they?...
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Thanks TH. Since I needed the coil advice I found the Thread.
HERE IT IS :bannana:
I read through the post, got the general idea.

Is there any specific coil that would work better?

I didn't see anything mentioned about timing?

Thanks for the link...
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