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MF 7 Tecumseh H70 Engine Help Needed


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#16 Utah Smitty OFFLINE  

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Posted August 31, 2011 - 10:53 PM

The engine is a flat head, so, do you mean the flat metal plate that covers the side of the block?

#17 Utah Smitty OFFLINE  

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Posted August 31, 2011 - 10:54 PM

Did you check the timing?
As you can see by Ranchkingron's pictures that coil points assembly is adjustable, can be rotated to change the timing.
The position of that unit and the point gap both affect the timing.
If it is firing to early it will cause a kick back.


How do you check the timing on this? I couldn't see a timing mark on the flywheel. If I know where to line up for timing, I can do the old method of using a test light to show when the points open.

Thanks for your reply.

Utah Smitty

#18 DH1 OFFLINE  

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Posted September 01, 2011 - 08:37 PM

How do you check the timing on this? I couldn't see a timing mark on the flywheel. If I know where to line up for timing, I can do the old method of using a test light to show when the points open.

Thanks for your reply. Utah Smitty


You need to find TDC using a dial gauge, it shows in the manual section how to do this and what the measurement is for the opening point of the points. Using the test light like you say is the way to do it.
I don't know what the measurement is as I can't download manuals here any more ever since I got my new computer???

#19 Ranchkingron OFFLINE  

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Posted September 01, 2011 - 11:06 PM

How do you check the timing on this? I couldn't see a timing mark on the flywheel. If I know where to line up for timing, I can do the old method of using a test light to show when the points open.

Thanks for your reply. Utah Smitty


If the stator plate (the plate that holds the coil and points) has been moved, the best luck I've had is to set it in the middle most are set from the factory at this point, but the using a light and a TDC gauge is best, I use a machined bar that bolts across the head with a straight line dial indicator but that's allot of money to spend for one use.

You can use a caliper with a depth rod (most good one have this) and place it on the edge of the cylinder bring the piston up to TDC zero it then back (BTDC) it off and bring it back up to the proper BTDC point .080 (neg .020") at that point the timing is set lock down the stator plate the bring the points lobe up to the high side and set the points.

I'm not sure I'm explaining this properly but that's how I did it and it runs perfect.

Here are the specs and procedure directly from the repair manual.

Ron

Attached Thumbnails

  • tec tming.JPG1.jpg
  • tec tming.jpg

  • Utah Smitty said thank you

#20 Utah Smitty OFFLINE  

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Posted September 02, 2011 - 12:44 AM

If the stator plate (the plate that holds the coil and points) has been moved, the best luck I've had is to set it in the middle most are set from the factory at this point, but the using a light and a TDC gauge is best, I use a machined bar that bolts across the head with a straight line dial indicator but that's allot of money to spend for one use.

You can use a caliper with a depth rod (most good one have this) and place it on the edge of the cylinder bring the piston up to TDC zero it then back (BTDC) it off and bring it back up to the proper BTDC point .080 (neg .020") at that point the timing is set lock down the stator plate the bring the points lobe up to the high side and set the points.

I'm not sure I'm explaining this properly but that's how I did it and it runs perfect.

Here are the specs and procedure directly from the repair manual.

Ron


Thanks for the info. This looks easy enough... I have a dial indicator, and a couple parallel bars I ground with a surface grinder. If I remove the head (have to do it anyway to decarbon it), couldn't I just place the bar across the top of the block, put the indicator on it (magnetic mount), and hold it firmly while rotating the crank?

Let me know if you don't think this would work.

Regards,

Utah Smitty

#21 Ranchkingron OFFLINE  

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Posted September 02, 2011 - 01:00 AM

I don't see any reason it wouldn't work just fine as long as it doesn't move, it would do the same thing I believe.

Ron

Edit once you get the piston in the proper place turn the stator till the points break (fires) then lock it down and regap the points.




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