Testing Mantis Tiller Coil

[OverKnight]

I have a Mantis tiller, model #101021, with the Kioritz SV-4/B engine. It's not starting and there is a spark, but appears looks pretty weak (it is getting fuel into the cylinder). How would I test the ignition coil on this engine? I'm having a difficult time finding the exact replacement (If I needed to replace it), and some coils seem to be unavailable, and all of them are surprisingly expensive. Can anyone suggest a source for the correct coil at a reasonable price?

Thank you.

[KE4AVB]

I have a Mantis tiller, model #101021, with the Kioritz SV-4/B engine. It's not starting and there is a spark, but appears looks pretty weak (it is getting fuel into the cylinder). How would I test the ignition coil on this engine? I'm having a difficult time finding the exact replacement (If I needed to replace it), and some coils seem to be unavailable, and all of them are surprisingly expensive. Can anyone suggest a source for the correct coil at a reasonable price?

Thank you.

I have a Mantis tiller, model #101021, with the Kioritz SV-4/B engine. It's not starting and there is a spark, but appears looks pretty weak (it is getting fuel into the cylinder). How would I test the ignition coil on this engine? I'm having a difficult time finding the exact replacement (If I needed to replace it), and some coils seem to be unavailable, and all of them are surprisingly expensive. Can anyone suggest a source for the correct coil at a reasonable price?

Thank you.

I thinking what you're thinking is the model number is actually the serial number for that Little Wonder. Yes the early model coils are being listed as NLA.

Being a 2 cycle that getting fuel and spark I would check the compression level and ignition timing before writing off the ignition coil. With compression gauge here I find that most 2 cycles need at least 100 psi to start. If low I would suspect a possible stuck ring or cylinder damage. If the ignition timing is off then no matter how good the compression is it wouldn't hit.

Also make sure you're using a known good spark plug as they do fail under compression.

Visually some coils arcs are very hard to see outdoors due color temperature of the spark. Basically needs to able to jump fairly wide spark gap. You also can't go the color of the spark either as in some places the spark can actually be orange due to sodium in the air. You won't be able to ohm out the coil as primary is inaccessible due the trigger setup. The secondary will a few kilo ohms but i don't the exact specs here.

[OverKnight]

Thanks, KE4AVB. I have a large spreadsheet where I've entered all of the model, serial, code, type, family, spec, etc. numbers, and it's possible I entered the serial number into the model cell.

I haven't checked the compression, but it feels similar to my Echo trimmer and blower. I'll find the time to pull the piston out to check the rings. Would it be worthwhile to replace them while I have it apart?

Instead of a key, there is a flat on the crankshaft to register the flywheel into the correct position, so I'd have to believe the timing is correct.

The spark plug was my first thought. I needed a plug last year, and the only one I could get at that time (an early Sunday evening) was an E3, with the split ground electrode; wasn't crazy about it, but it ran. I tried a plug from one of the Echo's, but no luck. I usually keep new plugs on hand for everything I have, but I don't have one for this engine.

If I do need a new coil, is there a different one that replaces the NLA original?

Thanks again.

[KE4AVB]

For checking the ring(s) and first look at the cylinder you can pull the muffler; much easier than pulling the cylinder and a less gaskets to replace if needed. With a small probe you check to see if ring will move will not be lot but if stuck it move at all. I am not talking about a rotation as this ring are usually pinned to prevent this. If you see a lot of scoring then PNC are shot; most likely for straight gassing. Replacement of the PNC might be prohibitive due to cost and equipment condition. THis is something that kill a lot 2 cycles here. I haven't price one for the Mathis as I haven't needed to.

As for ignition timing with flat instead of key sounds like should be fine too. I haven't one these a part yet but do see several of the Mathis and similar tillers. I have been calling these tillers Jack rabbits for the way they like to bounce on hard soils.

BGS might know if the newer coil will work or not since the same engine is used on some of the Echos. Really depend if they change the flywheel and/or coil mounting position.

If interested you could try out the accounting program I use that has an auto manager section that can keep track of the info you mention plus keep an history what you done for the customer. I believe it might be better that the speadsheet method. It will not cost anything other your time to try it. Now the payroll part doesn't work for me as it is for the UK. For a free program it fairly robust and actually a lot better than a paid for program I use before.

http://www.adminsoftware.biz/download.shtml

Mike and his team do get the bugs fixed rather quickly most times that happen on updates. Bugs do happen in all software. I personally use this program in both the office and the shop over a wireless network as I like to work in the office at night and not work the 400+ to shop everytime I need get the paperwork done or lookup to see if something in stock or not besides the frig is a lot closer. I have been using the program since early 2014 and really gotten dependent on it.

[bgsengine]

Yeah he coil is discontinued (Part number 15662611820) You may find some of those models listed with the A411000081 coil but that is for serial 320442 and up The unit is virtually identical to the Echo TC-210 (echo built them for mantis) if the rest of the machine is in excellent condition you could likely "upgrade" with a short block and parts for an Echo TC-210 but you'd be exceeding more than half the cost of a brand new one - Echo TC-210 MSRP is at $349.95

As to your issue - If you have a spark, you have spark - you cant determine weak spark by color - color is dependent on the surrounding air when it gets ionized from the spark You need a spark tester with a 1/4" gap - Takes about 10,000 volts to fire a good plug under compression - every 1mm of gap represents approximately 1,000 volts of firing voltage so if you can get a spark to jump the spark tester gap while hooked up to a plug that is installed under compression, you got plenty of spark available, regardless of color. Also the correct spark plug would be important they use an NGK BPM6A

if you are getting fuel and spark, I would check the spark arrestor screen and exhaust ports for being plugged with carbon (which would speak to poor fuel quality or running rich, if excessively plugged) and of course, compression test would need minimum of 90 PSI (more is better)

[KE4AVB]

Tnx, BGS. I keep forgetting about those darn spark arrester screens. Something I check automatically without even thinking about them.

[OverKnight]

Thank you, gentlemen. That's a good idea to try to check the rings through the exhaust port. Kill two birds with one stone, since I can check the screen at the same time. What is a PNC?

I downloaded and installed the AdminSoft program, and I'll see if it works for me. I use Excel spreadsheets for many different tasks, and for my small engine data, I have one sheet with every piece of equipment I have. It lists all model numbers, engine numbers, etc. Other sheets list carburetors and settings, ignition and setting, spark plugs, tires, belts, parts lists, etc. I've been using this for maybe 20 years, and as long as I enter everything correctly, it has worked well. There are zero calculations and formulae on this sheet; in this instance I use Excel as a fancy word processor. The resizable columns and rows, and the multiple sheets make it far easier to enter and view data than Word ever could, especially the multiple sheets.

Actually, I don't use the Mantis as a tiller, but with the dethatching attachment (which works quite well). Small tillers like this are really working hard to till hard soils, but they're very good for turning over a regularly tilled garden.

It's surprising that the original coil hasn't been superseded by another. There must be thousands of these out there. It's doubtful I'll be investing $349.95 into this machine. I do have a spark tester, so I'll try that this weekend, along with a compression test. I didn't know that the color of the spark could be changed by differing air conditions. Perhaps the spark plug is the whole problem. I tried the plug out of the Echo SRM-2100 trimmer, an NGK BPM7A. The Echo ran fine with this plug, but not the Mantis. I'll pick up a few of the BPM6A's.

I probably won't be able to work on this until the weekend; I'll sent an update then.

Thanks again.

[KE4AVB]

What is a PNC?

PNC = Piston aNd Cylinder just like BNC in our line of work usually refers to Bar aNd Chain.

NGK BPM7A. The Echo ran fine with this plug, but not the Mantis. I'll pick up a few of the BPM6A's.

BPM6A is just a little hotter plug tip temperature wise which can ignite fuels easier. But be careful of going too hotter as you can get pre-dentonation otherwords fuel igniting too soon without spark.

[OverKnight]

Acronyms... I work in a medical field, and medicine has cornered the market on acronyms. This one was tough to figure out, though.

Thanks.

[bgsengine]

It's surprising that the original coil hasn't been superseded by another. There must be thousands of these out there. .

Kind of tells you how well built those Echo machines can be.. your Mantis is approaching antique status - it was likely built in the middle 1990's I would say roughly 20-odd years old - typically parts like that are obsoleted and discontinued from production after a number of factors have been reached , including the last time a new unit was produced with that particular part, the overall demand, etc.

Your coil was quite a limited production - Only for the engine the SV-4 was built on (Echo TC-2100 tiller, and HC-1500 Hedge clipper) so there's very few models it would fit to - Mantis used Kioritz engines for many years , starting out with SV-2 (the first ones had points & condenser) , and constant revisions, improvements, design changes and upgrades (including the mandatory EPA emissions regulations that started kicking in the 1990's) I suspect you may find your machine was built around about 1992-1993 (the Mantis 7222E with SV-4B produced between 1/1991 to 8/1997, and your serial number is pretty low in the production runs so likely a first or second year model) So you can find SV-2 SV-2/B SV-3 SV-4 SV-4/A SV-4/B SV-4/C SV-5, SV-5/B , SV-6 - a lot of variations to be concerned with... So despite there being "thousands" of them out there - they use several variations of that base engine platform usually reflecting design changes - Ignition system changes would typically also require a new flywheel and a different block casting (cooling fin design, cylinder designs, etc could all force an ignition module re-design, even if nothing else really changed)