HSK600 2-cy Tecumseh 3h S-blower engine spark at BDC, not TDC (snapper 3201)

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  #1  
Old 01-07-06, 04:21 PM
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HSK600 2-cy Tecumseh 3h S-blower engine spark at BDC, not TDC (snapper 3201)

HSK600 Tecumseh 3h S-blower engine spark at BDC, not TDC

Ok I volunteered to fix a friends Snapper SB, yada-yada. He told me it worked last year, I think he got it from the dump ( a real beauty though).

Removed plug and put in a little gas. Now it did not start, but there was spark..... but when I removed the spark plug I noted that the spark was occuring at BDC (bottom dead center). I used a pencil to note BDC and watched the spark and magnets move by the ignition module. The flywheel has an adapter that adapts the wider flywheel key to the smaller crank key. This adapter in essence makes a flywheel that has a too-wide diameter fit a smaller crank diameter. If anyone reads this I'll post a picture.

It is clear that the key is 180 degrees out of what is needed to spark at TDC. Has anyone ever seen this? The flywheel key was partially broken and I think that the original owner knew he had the wrong flywheel so he basically removed the key and repositioned the flywheel 180 deg away from key, but this gave spark at TDC or close enough to run.

I plan to call a vendor to buy a new flywheel after he sends me a pix and I confirm that it is truely wrong.

Thanks
Bruce
 
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  #2  
Old 01-07-06, 06:41 PM
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He says it ran last year, so if the flywheel must be right, otherwise it could never have run at all. The flywheel key you are seeing is not an adapter. It is the correct key. These had a flywheel with a slot maybe 1/4" wide or so, and a slot in the crank about 1/8" wide or so. The key is somewhat "T" shaped, but with the top bar of the "T" offset to one side to the point that it's almost an "L" shape looking at it from the end. Sound like your key?

Here's my best guess so far: I think you're feeling the valve close instead of the piston going down. Both valves will be closed just as the spark occurrs. Some engines you can't hardly reach the top of the piston with a pencil through the spark plug hole, since the plug hole is generally offest to the valve side of the block. You'll feel the valves though. That's the only way I can think of you getting a spark when the pencil goes down.
 
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Old 01-08-06, 05:56 AM
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Thanks for the info, I will shoot a pix and link it (I'm charging battery now)

1- it is a 2-cycle no valves , except a reed valve on the carb

2- I will call this guy and absolutely verify it ran last year,BUT.... again my best guess is that it is the wrong flywheel/ key orinintation vs the crank. The key in the crank is shaved down so the opposite side of the adapter (non-keyed) side will grab the shaved down key. Yes the key actually looks to be filed down so the non-keyed side of flywheel can slide over it. Now remember there is this key adapter that provides a little key capture, even though it is shaved down.

NEED A PIX.... coming soon!

3- I measure 60-80 psi on crank, I'd think that this should not be a no start issue?

Thanks
 
  #4  
Old 01-08-06, 07:04 AM
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I talked to friend;

1- he told me HE NEVER USED IT! he bought it from someone who had no gas for him to try it!
This is NEW JERSEY: land of ********** everthing crooked!

I have taken a few pix:

this one shows the key adapter and the filed down crank key, so again I assume that the flywheel is wrong. If I position the keyadapter and key and tighten down flywheel, I get spark at BDC (this is a two cycle and I can clearly see the piston). Logically I'd think that the key and key adapter lock together....

http://home.att.net/~bsemanchik2/key..._filed_key.JPG


Two other photos of flywheel

http://home.att.net/~bsemanchik2/outer_flywheel.JPG
http://home.att.net/~bsemanchik2/inner_flywheel.JPG
 

Last edited by mattison; 01-10-06 at 03:53 AM. Reason: Edited statement that don't need to be on a family site.
  #5  
Old 01-09-06, 06:08 PM
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ok SO i'M answering my own thread...

I looked at two varaitions of my engine and there are two different flywheel keyings. This would result in different timing scenarios, why would tecumseh do this?

HAs anyone seen this?

Done
 
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Old 01-09-06, 10:40 PM
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Oh well, didn't realize it was a 2 stroke. I am not familiar at all with the "adapter" looking piece on the crankshaft. However, I don't see very many 2 stroke tecumsehs around here either. Snowblowers are pretty much non-existent here in the deep south. I suppose you're already doing what I would try to do, and find out what flywheel was supposed to be on it versus what is currently on it and go from there. Looks kinda messed up to me, lol.
 
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Old 01-10-06, 02:51 AM
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brucer, what is the engines' spec. number as well as the serial number? I'll provide you with the correct part numbers for what you may need. From appearances, i'd say the flywheel if from a vertical crankshaft walk-behind lawn mower, not a 2-stroke winter engine.
 
  #8  
Old 01-12-06, 05:43 PM
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Thanks for the offer,

HSK600-1639M 8085, this engine is on a snapper 3201 snow blower
on flywheel (wrong one) 7D.


I'll SN as soon as I can get to unit.
What is the torque on the flywheel/crank nut. I guessed at 24ft-lbs with lock tight (assuming that I get this fixed)



Thanks again
Bruce
 
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Old 01-14-06, 06:12 AM
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The spec. number you gave indicates that this is an AH series engine, not a Snow King (HSK). If the spec number you gave is absolutley correct (particularly the "M" portion) then the sleeve/key part number is 611032 and the flywheel part number is 611066. If the engine is in fact an HSK (1639 - "P" or above), then recheck the spec number and post back. The 8085 you gave tells us that it was manufactured on the eighty-fifth day of _8, you have to fill in the blank. 78, 88 or 98-model-year. 78 or 88 will be an AH series engine, 98 would be HSK (Snow King) engine and may have different part numbers. Flywheel torque is 30-33.3 ft. lbs.
 
  #10  
Old 01-14-06, 06:50 AM
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Thanks,
Your very knowledgable! I went to my local shop yesterday and he had given me the same numbers.

I did an edit on this thread because I provided the wrong model number.

Urr..... I screwed up, it's a N, I took a good light out in the garage:

HSK600-1639N 8085

A close up of spacer is:
http://cgi.ebay.com/NEW-SPACER-CLAMP...ayphotohosting

I guess that I'll order flywheel, since you have confirmed the flywheel number.

Thanks again, I guess the next reply will be when I get the FLYWHEEL
 

Last edited by brucer; 01-14-06 at 02:33 PM. Reason: wrong data in the model number
  #11  
Old 01-14-06, 09:01 PM
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I've seen this problem only once before. The one that I had to repair had a problem with the starter rewind. Someone put the wrong one on it and it was turning the wrong direction. Took me a long time --------

S/T
 
  #12  
Old 01-21-06, 01:56 PM
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Well it's runs great just needed the spacer below that changes the timimg of the flywheel for the two-cycle engine. The spacer sits in the flywheel and allows a flywheel with a bigger hole diameter and different keying. It alligns the flywheel key about 130 degrees away from the crank, note the dimples in the spacer. A pix is worth a 1000 wds. note the spacer and the flywheel keys. The spacer cost me ~3.00 $ with shipping. I could not believe that tecuMseh made a seperate flywheel for the 2-cycle.

I now see why shops are so cranky when a customer brings in a machine that was tampered with. This eposoid is a great example of tampering!
So basic troubleshooting is now sparc > fuel > timing!

spacer / timing adapter
http://home.att.net/~bsemanchik2/53_1.jpg

Flywheel.

http://home.att.net/~bsemanchik2/outer_flywheel.JPG
 

Last edited by brucer; 01-22-06 at 06:08 AM.
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