Engine Used to run but won't start now " 8hp 32" lawn tractor with electric start

[bobthewoodbutcher]

Re: Used to run but won't start now " 8hp 32" lawn tractor with electric start

I got the new coil installed and re assembled everything.
i hit the starter and it turned over but no pop on starter fluid. ( my friend is due back to fix the part he broke on the carb)

I put the spark tester in line with the plug and no "spark". I removed the tester from the plug and grounded it against the cylinder head and got a consistent light in the tester.
I removed the plug and grounded it hoping to see a spark... nothing. the same with the original plug and each of the 2 new ones, nothing
I held the ignition wire close the the head ( ground) but could not see a spark there either.
I seems i am not getting enough voltage the jump the gap.


At this point everything is new; coil, points, capacitor with plug wire. I could understand if I screwed up the timing but I need to get a spark.

bottom line, with everything new I am still where I was when I started out.

Something I did learn though was if you loosen the nut on the crank shaft so there is about 1 /16th gap and hit the starter when it cranks the flywheel will loosen up and you can remove it very easily without tapping it with a hammer. Do not loosen it too much or you will lose the woodruff key...experience.

My friend is back in town and we will start over and tackle this tomorow.

as always, any and all suggestions are appreciated

Thanks bob

 

[EngineMan]

Re: Used to run but won't start now " 8hp 32" lawn tractor with electric start

Did you set the air gap right on the coil, and have you tried it with the kill wire off the coil. seems very odd this one...!

 

[bobthewoodbutcher]

Re: Used to run but won't start now " 8hp 32" lawn tractor with electric start

I have changed the coils on push mowers with the coil on the outside of the flywheel (used a the business card). This one has the coil under the flywheel.

the owner of the shop where I am buying the parts said NEVER loosen the bolts that hold the coil frame. It was awkward fishing the wires to the points terminal and the screw that holds the condenser but I got that right watching you tube videos.

I have never seen a youtube video for setting the air gap where the coil is under the flywheel. I anyone knows of one please include it in your reply

 

[ILENGINE]

Re: Used to run but won't start now " 8hp 32" lawn tractor with electric start

the inside the flywheel doesn't have a distance from flywheel setting. What it does have is a way to rotate it in order to get the correct timing on fire. The reason he said to not loosen the screws is because it takes a dial gauge through the spark plug hole to position the piston to the correct place then rotating the coil to the correct location to start to open the points.

 

[EngineMan]

Re: Used to run but won't start now " 8hp 32" lawn tractor with electric start

"air gap" that may have been a mistake on my part...! what was (is) the strength on the flywheel magnets.

 

[bobthewoodbutcher]

Re: Used to run but won't start now " 8hp 32" lawn tractor with electric start

"air gap" that may have been a mistake on my part...! what was (is) the strength on the flywheel magnets.

I did not know how to measure the strength so I googled it and saw that there are a LOT of inquiries just like mine. All spark related, especially "lack of spark on a Tecumseh". Many said I may not see a spark in daylight and it probably would not be nice and blue.
I do get a spark with my tester but that is grounded to the head and there is no compression involved. If I put the tester in line with the spark plug wire including the plug the tester does not light up at all


Any way one site said to hold a screw driver lightly about 3/4" away from the magnets. I f it pulls the blade to the magnets from that distance the magnets are OK, My magnets pulled at 3/4" and maybe a little more, think this is adequate??

I was going to use a piece of flat stock on the magnets and pull it away with a fishing scale, but I do not know what poundage I should get. What should I be looking for if I do that?

thanks for not giving up on me. I cut grass right up until Christmas so I'm hoping I can at least do the last cut before then.

bob w

 

[bertsmobile1]

Re: Used to run but won't start now " 8hp 32" lawn tractor with electric start

If you get a spark when grouned to the head and none when the plug is inside the cylinder the secondary winding of the coil are toast.
In air you should be able to get a 1/2" to 3/4 " spark.
magnetos work on a collapsing magnet field energising a coil.
The faster the field collapses the more voltage is produced.
Spinning the engine without a plug allows the engine to spin a lot faster so it can make a duff coil look good.

Points were replaced with Hall Effect triggers because they are notoriously unreliable and require regular maintenance.
They use foil & tar paper capacitiors that have a finite shelf life, let alone running time so the first order of events should be to either replace the cap with a known good one.
Or to fit a points eliminator, if this engine is a strait magneto.
New in the packet is no guarantee that a capacitor / condenser ( same thing different name ) will be fit for use.
However if it is a stored energy sparking system then you are right up that famous creek in a barbed wire canoe with no paddle as you can only replace the points and cap.

Considering the effort required to get this thing running comparred to fitting any one of hundreds of better engineered replacements I think you are on a hiding to nothing.

 

[EngineMan]

Re: Used to run but won't start now " 8hp 32" lawn tractor with electric start

"Any way one site said to hold a screw driver lightly about 3/4" away from the magnets" this said by the book has being OK.

 

[bobthewoodbutcher]

Re: Used to run but won't start now " 8hp 32" lawn tractor with electric start

Well I am back again to discuss my mower. This has been a heck of a ride but the bottom line is that it is running again.
I finally gave up and bit the bullet paying $40 each way to have it delivered to my mower shop.

He said I miss wired the coil and had a short which he fixed.
My good friend did a not so good job rebuilding the carb but that had to be gone over again.

It has been raining since I got it back and there is not any grass to cut here in Jersey.

all in all I did not break the bank getting it fixed, so thanks to all of you who offered suggestions.

I am going to start a new thread because now that it is running I want to get around to cleaning and painting so it will be presentable.
My next goal is to make this beast quieter, so look for my new thread and bring on your suggestions.

 

[EngineMan]

Re: Used to run but won't start now " 8hp 32" lawn tractor with electric start

Good job, well done.......thanks for the feedback..!