Tiller won't start

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  #1  
Old 07-20-05, 11:03 AM
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Tiller won't start

We own a MANTIS tiller Model # 722M, engine # SV-4/B355876, E, Koritz Corp Made In Japan and this season we CAN NOT get it to start! We have been in contact with MANTIS doing the following things (but not specifically in this order)

Dumped out fuel
Cleaned gas tank
Added New fuel tank grommet and 3 new fuel lines
Added New “in tank” filter
Added New Start/Stop switch
Added New Spark Plug
Added New Choke Air Filter
Cleaned the muffler screen
Added grease to Worm Gear Housing
Added New Purge Bubble to Carburetor
Disassembled and sprayed carburetor with cleaner spray
Completed a “re-build” of the carburetor (diaphragms, needle valve, screen, etc)
Bought New gas container, doing proper fuel/oil mix

During all of this we had a couple of instances where the engine did try to run, but now it just won’t kick over. It seems to be getting fuel, because after many pulls on the start cord the spark plug is fouled with gas.

In checking for a “spark” there doesn’t seem to be one. This was done by leaving the cap wire on and shorting out the spark plug outer shell to the engine, with no apparent spark in the gap. MANTIS tells us that it is extremely difficult to see/detect the spark and that we should find someone that has an ignition coil checker.

In looking at the exploded view of the Starter, Pawl Catcher & Clutch diagram I see references to an Ignition Coil, Coil Spark Plug, Cap Spark Plug, Pawl Assy Starter and Pawl Starter. Are these the parts that create the “spark” for the plug to ignite the fuel? If so where could we find these parts, and how difficult would it be to replace these, if this were the problem.

We would appreciate all of the help and suggestions to get our tiller running again. We are retired and need to look for help in all areas trying to stay within our retirement budget.

THANKS IN ADVANCE FOR YOUR HELP!
 
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  #2  
Old 07-20-05, 02:49 PM
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like2know,

From your explination I too would agree with the “ignition coil” being the culprit. These can be rather expensive depending on make and model. It should be in the $20.00 to $40.00 price range. You should be able to acquire this part from Mantis or try looking at:

http://www.partsandservice.com/
or
http://www.smallenginepartswarehouse.com

God Bless,
Dave237
 
  #3  
Old 07-20-05, 06:00 PM
Azis
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If it has an On/Off switch, make sure the switch is not bad or the wire connecting it is not shorted. If you have or can use a multimeter, there are some tests u can perform to perhaps determine the condition of the coil. The only absolute test for them however is to exchange with a known good one. If the tests show bad then u can confirm it bad, but if all test are good, the coil still may be the cause.
 
  #4  
Old 07-20-05, 07:38 PM
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like2know,

Azis is correct in that the shorting switch is something you can easily check as I'm sure, as per your post, that you have thought of however, unless you are well versed in contunity testing or in the application of testing high voltage electrical devices I would strongly (ZZZZZ) suggest that you do indeed purchase a new ignition coil as this is the most likely electrical componet to fail.

God Bless,
Dave237
 
  #5  
Old 07-22-05, 01:34 PM
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Smile Bad Coil Or Not Bad Coil That Is The ????

Dave237 & Azis,
THANKS for your quick reply to our "Mantis Won't Start" thread. As far as replacing the coil, are there any SPECIAL things I should look out for. It looks like the only mounting hardware is 2 Allen head screws. In fact I tried to loosen them to see if I could just take the coil to a repair shop and have them do an electrical check, BUT the Allen set I have is either too small or too large. Is there such a thing as Metric size Allen wrenches??

THIS IS A GREAT WEBSITE!! THANKS AGAIN FOR YOUR REPLIES!!

DON
 
  #6  
Old 07-22-05, 04:47 PM
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like2know,

Yes, there are metric allen wrenchs and you may need a set in order to remove the coil. There's nothing specail to look out for but when replacing the coil you will need to gap the coil face to the fly wheel. The coil face needs to be between .010 to .014 away from the fly wheel. A couple of sheets of thick card stock placed between the coil face and flywheel during tightning will put you in the ball park. Afterwards, remove the card stock and rotate the fly wheel. There should be no contact between them.

God Bless,
Dave237
 
  #7  
Old 07-23-05, 02:02 PM
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THANKS for the Adjustment Note

Dave237,
THANKS for letting me know how to determine the correct gap between the flywheel magnets and the coil pick-up. Our tiller is still at a "fix-it" shop for a FREE estimate as to what our problem is. I'll keep you posted as to the outcome.

THANKS AGAIN<

Don
 
  #8  
Old 07-30-05, 02:03 PM
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"FREE" Estimate To Check My Tiller

Dave237 & Azis,
Thought you might like to know the follow-up on my getting a FREE Estimate from a local small engine repair place. They came back and said that it would be $160 for a "complete" tune-up. I had given them the list of things I had done:
=====================================================
Dumped out fuel
Cleaned gas tank
Added New fuel tank grommet and 3 new fuel lines
Added New “in tank” filter
Added New Start/Stop switch
Added New Spark Plug
Added New Choke Air Filter
Cleaned the muffler screen
Added grease to Worm Gear Housing
Added New Purge Bubble to Carburetor
Disassembled and sprayed carburetor with cleaner spray
Completed a “re-build” of the carburetor (diaphragms, needle valve, screen, etc)
Bought New gas container, doing proper fuel/oil mix
===================================================
I then asked what they would do different from what I had just completed. He said that they would have to check if I had done everything correctly!!
I asked to talk to the technician to see if they had checked the coil and the counterperson said that he was "sure" that he had.

I don't mean to be cynical but I'm not sure they really took much time to really check things out, but just gave me the standard $160 Tune-up answer.

I don't own a multi-meter but do have a neighbor that works a lot on cars and I'm going to see if he can check the coil for me. Until I hear that the coil is GOOD I still think that the lack of a real spark is our problem.

Any further suggestions you guys might have would be appreciated.

THANKS,
Don
 
  #9  
Old 07-31-05, 11:31 AM
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Don,

$160.00 is a very steep price indeed being that you have already replaced those items that are to be replaced again if in fact; that's what they do. By your description of the problem I again would opt for the ignition coil being the culprit.

You can save this expense with a new coil ($30 to $40) however, it will be your headache in installing and adjusting. If you don't mind spending your time then I would order a new coil and see the results and go from there. Also, too, there are cases that a coil will ohm out "test good" but it's inductive values or internal cap has changed and will not deliver full voltage for a good hot spark. In either case, a for sure way is to replace it.

God Bless,
Dave
 
  #10  
Old 08-02-05, 09:08 AM
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Replacement Ignition Coil

We're still looking to fix our Mantis Tiller. I checked many local dealers and the new ignition coil price ranges from $95 to $112 and we're concerned that if we get the part the tiller still may not start then we're out the $$$.

On the WEB we've found a "universal ignition coil" (Mega-Fire) that claims to fit 95% of 2 stroke engines and the cost is under $20 - the site is:

http://www.psep.biz/store/universal_...c_ignition.htm

Do you think that this would work with the Mantis (Echo engine)?

THANKS IN ADVANCE FOR YOUR REPLY!!

Don
 
  #11  
Old 08-02-05, 09:30 AM
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I'm not familiar enough with your particular engine to suggest using the coil on the site you provided.

If the correct replacement coil for your particular engine cost in the $100.00 range then I would suggest letting the repair shop do the job. With the coil being replaced in the $100.00 range I don't think $60.00 is to much for labor and also you will have the peace of mind that your trouble is over.

Cheese or Azis could way in on this issue as I’m sure they are familiar with this engine.

God Bless,
Dave
 
  #12  
Old 08-03-05, 12:28 AM
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Nope, the mega-fire module will not help your situation. This module isn't a coil, and doesn't replace a coil. What it does is replace the mechanical breaker points in old engines that were made back when breaker points were used. Your engine doesn't have points and this module would be useless. Try checking on ebay for a coil. There are deals to be had there sometimes.
 
  #13  
Old 08-03-05, 06:49 AM
Azis
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The engine #'s do not ring a bell and is possibly not a common engine used on other equipment.
With the coil being that high priced AND a non-returnable item, it may be well worth letting the shop do it as if that is not the problem (by some strange chance) you will not be the proud new owner of a spare $100.00 coil.
Another thing to consider is $160 is rapidly approaching the price of a new tiller. Depending on age of equipment, I use a very GENERAL rule of thumb, 50% of new for repair, if more replace. If the rest of the unit is in good shape and has been dependable this repair if succesful would be (IMHO) worth it, especially as it is not mechanical (IE:no moving parts involved that just wear out)
 
  #14  
Old 08-03-05, 07:29 AM
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$160.00 is way too high a price for a tune-up on this machine. Get it back. Buy a Briggs & Stratton spark tester, part # 19368, remove the four screws that hold the flywheel cover/starter assembly to the engine, remove the single, small guage grounding wire at the coil (the black, square-shaped part with the heavy-guage wire running to the spark plug), check to be sure you have proper flywheel magnet to ignition coil air-gap (.012"), reinstall the flywheel cover/starter assembly to the engine, with the spark plug still in the cylinder - remove the spark plug wire from the spark plug and attach it to the Briggs tester (on the long, silver post), attach the alligator clip to the spark plug (at the top, small terminal), pull the engine over briskly. You should have a spark jump across the large gap in the tester window. If spark, you have a bare grounding wire or faulty kill switch - replace both, (after replacing these (if needed) recheck for spark using the tester with everything hooked up as usual). If no spark, replace the coil and gap properly and reinstall the grounding wire, reinstall the cover/starter and away you go.
 
  #15  
Old 08-03-05, 11:55 AM
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Flywheel Magnets

Dave237, Cheese, Azis, puey61,

THANKS!! For your great suggestions.

In our continuing pursuit to get the tiller running without spending a lot of money we went to the local library and found a book “REPAIRING YOUR OUTDOOR POWER EQUIPMENT” by Jay Webster. It really covers how things work and how to troubleshoot and possibly repair different equipment. He covers quite a bit about the ignition coil but the following paragraphs caught my attention, and I quote:
(Pg 120)
“ Several parts of the flywheel are very important to magneto operation. Weak flywheel magnet magnetism will prevent proper coil operation. The result will be no spark or weak spark to the spark plug. Weak magnetism is usually caused by dirt or rust on the flywheel magnets. Flywheel magnets can also lose their magnetism over time.”
(PG 122)
“ The flywheel magnets can lose their magnetism. To check for magnetism, place an un-magnetized screwdriver approximately ¾ in. (19mm) away from the magnet. It should be strongly attracted to each magnet in the flywheel. Most magnets are cast into the flywheel. Some older flywheels have replaceable magnets. A magnet that has lost magnetism must be replaced. Either replace the individual magnet or replace the flywheel. “

On our Mantis tiller flywheel there are 3 magnets ¾, 1, and ½ in. With the 1 in one being in between the other two. We did the “screwdriver” check and it was only attracted to the 1 in. one. Our visual check did not show any rust or dirt on the surface of the magnets, but there are a series of horizontal lines on each one.

Maybe the coil is not the problem; maybe it’s these magnets. Looking forward to your replies on this.

I’m so glad that my wife found this <doityourself.com> site!! I’m spreading the word to all of my family and friends.

Don
 
  #16  
Old 08-03-05, 05:43 PM
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You could pursue this matter further and eventually learn the entire engine theory and operation. I think the others who have contirbuted are aware of the magnets and their function although time and experience has proven failure of the magnets is very rare. If the magnets will hold a regular sized scredriver, this is not the problem.

Buy a Briggs & Stratton spark tester, part # 19368, remove the four screws that hold the flywheel cover/starter assembly to the engine, remove the single, small guage grounding wire at the coil (the black, square-shaped part with the heavy-guage wire running to the spark plug), check to be sure you have proper flywheel magnet to ignition coil air-gap (.012"), reinstall the flywheel cover/starter assembly to the engine, with the spark plug still in the cylinder - remove the spark plug wire from the spark plug and attach it to the Briggs tester (on the long, silver post), attach the alligator clip to the spark plug (at the top, small terminal), pull the engine over briskly. You should have a spark jump across the large gap in the tester window. If spark, you have a bare grounding wire or faulty kill switch - replace both, (after replacing these (if needed) recheck for spark using the tester with everything hooked up as usual). If no spark, replace the coil and gap properly and reinstall the grounding wire, reinstall the cover/starter and away you go.
 
  #17  
Old 08-04-05, 01:36 AM
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Also bear in mind that there is probably only one of those "magnets" that is actually supposed to be a magnet. The others are just metal weights to balance the flywheel by offsetting the weight of the magnet on the opposite side.
 
  #18  
Old 08-04-05, 07:00 AM
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Don,

All the guy's that have weighed in here are the cream of the advice crop. As they have already stated, it's very rare for flywheel mags to lose enough of their magnetism to contribute to weak spark. Even in this event the fly wheel would cost more than the ignition coil.

You may be looking for a cheaper part to replace however, without having the experience of hands on problem solving while studying the mechanical and technical side can lead to looking at the technical for a cheaper fix while over looking the more expensive but obvious.

I would certainly consider Azis advice as to where the cost of repair is worth it as opposed to replacing the tiller however, with all other electrical components assumed good I still would suspect the ignition coil as the problem as this is the most common failure. Being that you have studied and are in the know as to the workings of the engine; ignition replacement is a straight forward process and if done correctly should remedy the problem. Before replacement make sure that the ground wire is well attached to the engine block and that it has continuity from the coil to the engine block. Without this ground you will have a dead (assumed defective) coil. Also, as Puey suggested, the briggs spark tester is cheap insurance against buying a coil you don't need and your real problem being related to a fuel issue.

Also, did you set spark plug gap correctly? About (.030).

Best of Luck and God Bless,

Dave
 

Last edited by dave237; 08-04-05 at 07:12 AM.
  #19  
Old 08-11-05, 08:54 PM
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Tiller "START PROBLEM" Resolved!!!!!!!!

Dave237, Az8s, CHeese & Pluey61,
GOOD NEWS here at our house.

I called another repair shop here in San Jose, CA (Sharpening Mechanics) telling them all that I had done and still having the problem of not being able to start the Mantis tiller. The owner (Grant) told me to bring it over and he would look at it and see if he could determine what the problem was.

After 2 days he called back and said the the Start/Stop switch was defective and when he bypassed the switch there was a good spark. So he put in another switch (I had replaced it during my trial and error troubleshooting - BUT it must have been bad) and the tiller kicked right over and he had it running, tuning the carb for smooth operation. He only charged us for the switch and a nominal fee for his mechanics time.

We'll be playing in the dirt tomorrow - THANKS AGAIN to you all for all of your suggestions.

Don & Peg
 
  #20  
Old 08-12-05, 01:14 AM
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Great! Glad you got it, and thanks for the update!
 
  #21  
Old 08-12-05, 09:57 AM
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Ditto!! Sounds like some good clean Fun
 
  #22  
Old 08-12-05, 04:25 PM
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Don,

We had all assumed the switch to be good per your first post however, you had the sixth sense and persued it. Glad you got it running.

God Bless,
Dave237
 
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