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Discussion Starter #1
Hey guys. I have a Tecumseh HMSK85 155905B and cant find the valve clearance spec anywhere. Does anybody know what it is supposed to be?
 

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I believe it is:

HMSK80, VM80, TVM195 (A-K), HM80 Min:.008 / Max.012 in.
.203 / .305 mm.

Same for HMSK100 so I assume same for HMSK85.
 

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Discussion Starter #4
Thanks for the replies!

I have seen both figures. So which one is correct?
 

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Discussion Starter #5
Update:

I cleaned up the valves and checked the clearance and I am at 0.010 without lapping them.

If it is 0.008 - 0.012 then i am right in the middle. I am still waiting on gaskets but would like to hear from you guys before I button her back up!
 

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I would go with what the manual calls out.
 

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spec is .008 on intake and .012 on exhaust- this is what the tecumseh book at the shop says to use. if your engine is spiting flames out the exhaust or your muffler is glowing red hot and you have already tried to solve a lean condition this is more then likely your problem. now if you hear a pffting noise coming from the exhaust definitely look into the valves. more then half of them that come into the shop i work at have valve issues, but it is much more common on engines with fixed jet carbs
 

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arienskids: where did you see that spec for the HMSK85? The only spec I have seen says 0.006 +/- 0.002". Also, the 0.008 and 0.012" spec is usually min max, not intake and exhaust.
 

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Discussion Starter #10
Ok guys, this here is the issue I have found.


Has anyone followed one of these specs and can say that it worked for them? They vary quite a bit. Ironically i am at 0.010/0.010 right now (dead nuts between 0.008 - 0.012) and the machine runs fine. If it is in-fact 0.006 then i need new valves cause these have gone too far.
 

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Grunt: I have seen that chart, but it does not include the HMSK85. The chart I mentioned on p64 of this manual does list the HMSK85, and it is the only Tecumseh manual that I have found with that specific engine.

file:///C:/Users/Paul%202017%20PC/Desktop/tools%20and%20manuals/outdoor%20power%20equipment/small%20engine%20specs%20and%20manuals/Tecumseh_quick_reference.pdf

and yes, I have always used the Tecumseh specs and they have worked well.
 

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Discussion Starter #12
@paulm12
when you say it mentions HMSK 85 i see that mentions HMSK 80 - 100

Is 85 included in that generalization?

I am having trouble finding ANY literature that specifically mentions HMSK 85

And your post of that manual (which is excellent by the way) is the first i have seen that mentions 0.006 . Everyone else says 0.008 - 0.012 which they either claim is a min/max figure or a intake/exhaust figure.

Still not convinced....
 

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If it is in-fact 0.006 then i need new valves cause these have gone too far.

Actually, if you had .006, then you would file\grind a little off the stems to reach .010. If you had .010 or larger gap and you wanted .006, you would need new valves if lapping them didn't close the gap.


I personally would go with the .010 since the valves will continue to wear into the valve seats AND this isn't rocket science, it's a low RPM snow blower motor.


The HMSK80-100 includes the HMSK85 and the HMSK90.
 

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Discussion Starter #15
Actually, if you had .006, then you would file\grind a little off the stems to reach .010. If you had .010 or larger gap and you wanted .006, you would need new valves if lapping them didn't close the gap.
Right, we are on the same page here. 0.010 is what i have right now. If 0.006 is the spec then i need new valves. Which is not to say I dont trust literature straight from the manufacturer. I just see the 0.008-0.012 spec everywhere else.

I should mention the motor runs fine. I am simply doing "preventative maintenance" to hopefully avoid downtime in the middle of winter.
 

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baker300 and grunt: ok, I am seeing the conflict now between the 2 documents. The quick reference guide says 0.006" and the technicians handbook says 0.010", both +/- 0.002". I am changing my earlier comment, and I would go with 0.010 nominal.

Note that my shop techs told me 0.010" for my engines in this size range. Sorry for the confusion I created.
 
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