hank1010

TD 6 compression release lever

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So I have aquired a td6 some time ago...and I am just now getting to it!  So I have spark, and fuel, but it won't start.  It looks as if the compression release lever is not factory.  It is a threaded rod that was bent and made to work.  Also, I have to hold the lever down while trying to start. It does not stay in the lowered position.  Is this normal?  All the videos I see, the operator can start it...and then "throw" the lever...mine has to be held down while starting.  Last thing...how can I tell if the compression release is working, or how to I adjust the linkage?  I will get some pics up soon! Thanks in advance for the help!

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cant say about your bent lever  but if it cranks fast then it is on gas side ....... should only control fuel and valve/ flipper function

gas/spark.... flipper should be ok ......more choke  or ether to see if it coughs...then check fully flipped (broken spring)  for vacuum

..gas/throttle/ lever a little higher   once you get white smoke,back it off to the center of that travel should run there

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21 minutes ago, hank1010 said:

So I have aquired a td6 some time ago...and I am just now getting to it!  So I have spark, and fuel, but it won't start.  It looks as if the compression release lever is not factory.  It is a threaded rod that was bent and made to work.  Also, I have to hold the lever down while trying to start. It does not stay in the lowered position.  Is this normal?  All the videos I see, the operator can start it...and then "throw" the lever...mine has to be held down while starting.  Last thing...how can I tell if the compression release is working, or how to I adjust the linkage?  I will get some pics up soon! Thanks in advance for the help!

You should notice quite a difference in how easy the engine turns over when you move the decompression lever if it is working properly. It will turn over much easier when the starting valves are open in gasoline mode.

If you have an assistant move the decompression lever while you watch the linkage on each side of the engine you will know whether it is moving. There is a shaft that goes right through the engine that connects the linkage on both sides. On the carb side, the linkage is right behind the carb, so not quite as easy to watch, but you should see or feel some linkage movement.

There is a rod that is part of the linkage behind the carb that goes up vertically toward the engine head that connects to the starting valve mechanism under the valve cover. This rod is what indirectly opens and closes the starting valves. If this rod is moving, and you think the starting valves may not be opening and closing, you might want to take the valve cover off to make sure the connections under the cover are intact.

There is adjustment on some of the linkage components..

You say you have fuel, is that to the carb or have you pulled your spark plugs to see if they are getting fuel on them ?

The decompression lever on your TD6 may be different than on my TD9, but it should stay in either position without you having to hold it. 

Hope this helps some. There are TD6 owners on the forum that will likely chime in and may be more helpful than me..

Good luck,

Grant

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Sorry mmi, was typing my reply when you responded, didn't realize you had already responded about the engine turning over easier in gas mode ....

hank1010, the other thing you need besides fuel and spark is air, so make sure your air intake system is free of any obstructions..

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The linkage behind the carburetor is where the locking mechanism for the lever is. there is a short spring that holds it engaged until you over ride it by throwing the lever up. If the spring is missing or unhooked it will not stay engaged.

George

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George is right the small spring on the carb side of the linkage could be missing! On mine that spring was gone and the lever would not stay down. once I added that spring the lever stayed down. Took me 2 years to figure that out, I think it waas Magic Mikey that showed me the light.

Spark, gas , compression it should try to run.

Yea we need pictures!

Regards,

 Chris

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I tried the attach files here to add a picture. not sure how well it worked? trying to not use photobucket as they are holding my pictures for ransom.

Regards,

 chris

DSC06712.JPG

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Yup, that is the spring. If it is not attached, the part that it is hooked to on the bottom just swings down on the big bolt to the left. That is the lock lever. thanks Sugarmaker

 

George

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Your Welcome! Hope it helps Hank.

Regards,

 Chris

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Hey guys, I am thankful for all the help so far!  I will try and get pics on this post.  I have done a little tinkering this morning and here is what i have come up with...took the valve cover off, and notice number 4 compression valve was stuck.  I sprayed some Kroil on it, and tapped lightly with brass punch, and freed it.  Everything else under valve cover looks good.  All valves are moving as they are suppose to.   It looks as if the spring that chris's picture shows, is also on mine.  maybe mine is stretched out?  I have been able to get the dozer to "cough" with ether, but that is it.  I have double checked the firing order, and took the mag cover off, and mine turns CCW.  So i put the no.1 plug on the no.1 spot on the cover, and went CCW 1-3-4-2.  So i still didn't get anything, and I though i got spark, go fuel, maybe no air.  I then took off the intake, and noticed that when i took it off, the linkage that controls the butterfly valve, is real close to the spark plug (normal?).  and when i took the intake completely off, the butterflies are OPEN.  so in short, the decompression lever it UP, or in DIESEL mode, and the butterfly is OPEN.  and when i push the lever down, is seems to CLOSE the butterfly.  This is in reverse.  It looks as if the linkage that controls the butterfly may be homemade, or had the lever welded on.  I will enclose some pics, and let me know if it seems to be correct, or if there is something i am not seeing.  i the picture of the backside of the intake, that is how i took it off.  IMG_4952.thumb.JPG.e2f8fc9001600b83b2591c7813f0b171.JPGIMG_4952.thumb.JPG.e2f8fc9001600b83b2591c7813f0b171.JPGIMG_4952.thumb.JPG.e2f8fc9001600b83b2591c7813f0b171.JPGIMG_4952.thumb.JPG.e2f8fc9001600b83b2591c7813f0b171.JPGIMG_4952.thumb.JPG.e2f8fc9001600b83b2591c7813f0b171.JPGIMG_4952.thumb.JPG.e2f8fc9001600b83b2591c7813f0b171.JPGIMG_4952.thumb.JPG.e2f8fc9001600b83b2591c7813f0b171.JPGIMG_4952.thumb.JPG.e2f8fc9001600b83b2591c7813f0b171.JPGIMG_4952.thumb.JPG.e2f8fc9001600b83b2591c7813f0b171.JPG

IMG_4953.JPG

IMG_4956.JPG

IMG_4957.JPG

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ok i thought i inserted photos, how do i do that?

IMG_4952.JPG

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10 minutes ago, north of 60 said:

Sorry mmi, was typing my reply when you responded, didn't realize you had already responded about the engine turning over easier in gas mode ....

hank1010, the other thing you need besides fuel and spark is air, so make sure your air intake system is free of any obstructions..

does not matter who got thru the door first

since it is apart set up on bench and tap some fuel to carb  remove plug on bottom  and run some thru while actuating the flipper to make sure you have full flow and full shut off,dont open carb any further until/unless needed, you have parts in hand $75-200

check the flipper ground also as that plug/cap is out and bugs may have nested

before  putting back on ,then I would go with spark and delivery most of the parts look old and new does not hold up well  (needs true copper wires)    near every time I run mine I swap parts into the cub to confirm working....spark should be blue ,jump at least 1/2" and make you cringe  fat original plugs also liked a wider gap......  c-86     d-16/21 only work with certain gas

 

then gas needs to be  this weeks and premium  once all works you could test going cheap 

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ok.  So you think the linkage looks normal, and how it should? I do have spark.  I have been running an inline spark tester while i am trying to turn over to make sure its sparking.

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Hank,

I rely on the manual to sort out the linkage. But I don't see anything wrong. Experts may be alo0ng later to critique.

(FYI you posted 9 of the same picture. not sure you intended to do that?) they all look good so you got that down.

Sure looks easier to change plugs with that center manifold section off. Its a bear with it on. Don't ask how I know.

Have the plugs been out and cleaned/ replaced? I would suggest new wires and plugs if you havent already?

in line spark tester is good.

Not sure on the flipper positions? Need to be open to suck gas into cylinders during running on gas I would assume. But aren't there another set of flippers in the block ?? I am not well versed on the inner workings of these engines yet!

 I see the small spring in position. so that is not the issue. May need to check the position of the linkages on the starter side of the engine coming from the handle. There are adjustments there too, that someone could get out of whack. Anyway starting by holding the handle down is not the end of the world. Cut a block of wood to hold it in position against the dash.

Keep cranking! gently

Regards,

 Chris

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incorrect info on post removed

Edited by north of 60
incorrect info

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The butterfly valves are CLOSED in gas mode, forcing the engine to draw through the carburetor through the two smaller holes in the intake and head. The butterfly valves "snap" shut and make a vacuum seal when all is working as it should, sometimes you have to reach up behind the manifold and push the "V" lever all the way to get the engine to start on gas.

Number one on the cap isn't necessarily the right place for #1 wire, depending on how the mag has been monkeyed with in the last 50 years or so. Check that first.

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Thanks for correcting that ...  I learned something new today too ...

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16 hours ago, hank1010 said:

ok.  So you think the linkage looks normal, and how it should? I do have spark.  I have been running an inline spark tester while i am trying to turn over to make sure its sparking.

flipper could still be not seating to full vacuum side (where it draws from carb)  lube all well

you have to confirm the spark is making it "HOT" ALL the way thru plug   including ALL grounding surfaces   I source that test thru the battery or into the cub   90% of plug issues are regional gas and newer than 1990 champion plugs   use different brand of known working plug + copper wires

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So I am at a loss! lol.  I have come to the conclusion that is must be a spark issue.  I have checked and cleaned the flapper in the intake, and it seems to flow well and seal well.  With the intake off, I gave her a shot of ether in the intake port, and tried to start.  NOTHING.  not even a cough...I still have the spark tested inline, on no.4 plug, and can see i still have spark.  But wouldn't the engine try to start, or even cough, or do something if i shoot a bit of starting fluid in the port?  i tried both the big port, and the small port, at different times, and at the same time.  with the decompression lever down, as well as it up.  trying all possibilities.  I do have newer champion plugs, if i remember right, D89?  I have newer plug wires.  I have not put a new cap/rotor/copacitor.  That will be my next thing.  I would have thought i would get SOMETHING to happen.  I am

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DON'T try starting it without the manifold on the engine! It will rev up instantly , and over rev badly, just running on ether. You must have it out of time. Check for split overlap on #4, that is firing on #1.

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Ok. Good thing she never for going.  What does split overlap mean?  

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Split overlap is when the piston is at TDC between the end of the exhaust stroke and the beginning of the intake stroke. The overlap built in to the cam means both valves are slightly open at the same time. So, when one cylinder is at split overlap, the cylinder directly across the distributor cap is at TDC compression, or firing position. If #4 on your four cylinder is at split overlap, then #1 should be firing.

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Not sure but even if out of time it should at least pop. Doesnt sound like you should try it with out the manifold back on. So I am not a fan of Champion plugs at all. I cant remember what plugs i used but they did not match the long electrode ones I took out. But they did work fine and it fired right up on gas.

Good luck, keep cranking. Maybe take a plug out ground it and watch for actual spark at the plug electrode?

 Regards,

 Chris

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intake installed with raise fuel mix to better levels

any plug may test good but not fire under compression  .... especially champion and cheap gas

that is why I confirm working in a running engine...hot spark in the chamber and fresh gas is needed for this type of restart.

worked for days thinking was good otherwise      if the timing/mag trip is correct CCW + compression/valves sealed tight

the only issues can be what we are working on in this post

w everything installed   30 sec crank on full battery then add 3 sec of ether  continue crank 15 sec  rest 15 crank 20 sec if it did not pop wait 60 and try again if still nothing suspect spark

the same can be done by adding 1 TBS good gas direct to intake be prepared for haircut 

recheck spark timing compression   after doing that all day on one that ran 6 months ago   you swap in known working parts   and 1 plug wire has an intermittent loose internal wire....:ph34r:

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