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Quark's Avatar
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Join Date: Oct 2001
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11-10-02, 09:32 AM   #1  
Lawnmower jerks cord when I pull

Okay, gotta MTD Tecumseh Vector VLV synergy with a little history.

Hit a tree stump -> result: carborator flooding -> fix: re-level float

In the process of checking carb problem, stripped spark plug thread -> fix heil coil

In the process of removing parts, blade goes on upside down -> result: broken blade key -> fix: new adapter kit ( ouch $.25 keys ).

Finally, I pull, I crank, MTD pulls back (violently when there is an engine catch).

The dissapointment: From what i've read improper compression, from remounting the cylinder head ( from the heil coil surgery ) will not cause a problem like this. Also, as stated in the Sci_Electronic_Repair_FAQ.txt, I have two choices, 1) an engine overhaul or 2) stop trying to repair it (quit paradoxical (if that's even a word)). Anyways, the optimistic component of my split personalities, told me to mo-z over here & see if a doityourselfer would be able to diagnose this behavior. Also, if I do loose all my marbles and attempt the dreaded reconstructive surgery, a) what are my odds of losing some important pin that surely isn't findable a your local lawnmower junkyard & b) what would be a target when i finally break it down.

Yes, with proper instruction I'm crazy enough to break it down to the bearings.

Any help guru's - Oh, just a side note -> The history that is listed above was all accomplished by a post similar to this (regardless of my clumsiness, which started the entire process as well as adding fuel to it).

 
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11-10-02, 12:12 PM   #2  
buttlint
Quark. Calm down bud. No major damage , just a sheared flywheel key. But before you go any further, make sure the crankshaft isn't bent. Remove the plug, hold the bail and give it a pull. Have someone do that with the mower tilted back, and watch the blade bolt and see if it wobbles. If it does, your crank is bent. If not, you are ok. Could have been a loose blade bolt too.

 
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11-10-02, 01:59 PM   #3  
Tcumcman
Vector Problems

Quark,

How did you "adjust the float level" on a carb that it CANNOT BE
DONE on ?? Hitting a root WILL NOT cause the carb to flood, and
the way the non-metallic bowl carb is designed, there is NO float
setting except to clip the bowl in place. A flywheel key CAN CAUSE
the "kick back" you describe, and if you hit a root, it's probably
the reason for it, due to a sheared key. The Vector engine uses
a "unique" flywheel key (part # 611154), and this MUST be used
for it to work properly. Last, but not least, the mechanical comp-
ression release on the camshaft can also be malfunctioning, and
can cause the SAME symptom as a sheared key. I'd check key 1st
and then proceed further if necessary.

Tcumcman

 
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11-10-02, 04:14 PM   #4  
mikejmerritt
If it turns out by some chance you don't have a sheared flywheel key make sure the blade is tight. The problems you have now do sound more like a blade that is loose or not locked to the shaft.....Mike

 
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11-10-02, 11:35 PM   #5  
I agree with all....you have a sheared flywheel key or possibly a loose blade, and be sure to check that crank to see if it is bent, as mentioned. Let us know what you find!


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
Quark's Avatar
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11-12-02, 07:35 AM   #6  
Wow guru's. Excellent responses. A couple of questions.

1) buttlint, By the holding the bail, do U mean, hold the part of the shaft that holds the literal blade, or hold the blade adapter mount?

2) buttlint again, by the blade bolt, do U mean the center (bolt connected to the shaft) of the three bolts that hold the blade?

3) everyone, is the blade supposed to be torked, I know the cylinder head is supposed to be & I'll definitely put that tool on the purchasing queue?

4) everyone again, as U can see, i've blundered my way thru this entire procedure. Flywheel removal seems like a delicate process, calling for more precision than I've conjured B4. I know there is a tool (rectangular block) , that mounts into the flywheel so you can just screw it off nicely, instead of the hammer method. With my history, that doesn't seem enticing. Know where to find those on the net? The hardware & lawnmower shops around aren't very well stocked. I'd like to skip the middleman.

Oh, tcumcman, the actual float (or that thing that looks like a tongue) has to small poles pertruding from its sides & those fit into clamped grooves. I had to do a double take (my first time looking at any type of machanical organs) to see that one of the poles had popped out of is clamp. A small problem that actually turned me into an on-the-fly fireman (that's another hole story). I can't remember who I got the info on the carb situation, but whoever U were thanx, it definitely solved the flood problem.

Last question, tcumcman, know where I can find that special part (key)?

 
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11-12-02, 03:00 PM   #7  
Tcumcman
Flywheel Key

ANY Tecumseh Dealer should have a 611154 key

Tcumcman

 
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11-12-02, 05:10 PM   #8  
buttlint
Quark, there is another method for checking the crank. I use it in the shop, when I dont have an assistant to pull the rope. I think that it is a little safer, and a bit more accutate than what I was describing previously.
I have a lazy-susan that I found behind a cabinet shop.( I suppose an old turntable would work just as well.) First I remove the engine from the mower, and drain out the engine oil. I then place the engine, upside down, on the lazy-susan. (blade and adaptor off of course) I then suspend a string with a plumbbob attached, from the ceiling of the shop. I center the plumbbob over the hole in the crankshaft, and then simply give the turntable a spin. While it is spinning, you can clearly see any wobble, or bend in the crankshaft.
I hope this helps, 'lint.

 
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