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Engine stutter when throttle is applied


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I wanted to report back after finding the cause!.

I found that the the #2 cylinder and intake tube did not meet up flush.  The aft part of the intake tube touched the cylinder head first and left a 1/32 gap on the front side of the intake tube.  From the outside, the intake gasket looked to be in good condition but after removing the tube you could clearly see that the rear side of the gasket was compressed and the front didn't even make contact...  It was sucking in enough air to mess up my mixture.  I replace the gasket with a new one that was a bit thicker and the problem almost completely went away.  It still not flush, and sucking in some air, so I'm going to have my AP look at it again when he gets back from vacation...

Its a relief to just know the cause of the problem.  I'm hoping some RTV can completely solve the problem but it's never that easy is it?  

Also, While i was searching for this issue I found that my intake duct had 2 tears... I'm pretty upset that this wasn't found during my pre-buy inspection.  This is one of those mooney things that is well known and should have been found by a MSC.  I'm discovering that my pre-buy inspection was not worth the money I paid.

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Great follow up, Chump.

Focus on the proper fix... RTV doesn’t sound like a good idea....

If the proper fix doesn’t work, something else is out of place...

If you can’t get the proper fix... post some pics of what you have...

 

Check in with @Alan Fox he had a few intake ‘Ducts’ (?) available...
 

It could be just the words we are using today making things confusing... :)

Best regards,

-a-

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1 hour ago, flyingchump said:

Also, While i was searching for this issue I found that my intake duct had 2 tears... I'm pretty upset that this wasn't found during my pre-buy inspection.  This is one of those mooney things that is well known and should have been found by a MSC.  I'm discovering that my pre-buy inspection was not worth the money I paid.

Who was the PPI done by? PM me if you fear them, thanks.

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1 hour ago, flyingchump said:

I wanted to report back after finding the cause!.

I found that the the #2 cylinder and intake tube did not meet up flush. .......I'm hoping some RTV can completely solve the problem but it's never that easy is it?  

the 2 surfaces (intake pipe and cylinder) should be parallel to each other, I'm not a fan of RTV used were fuel is present. Get a dab of RTV and let it cure, then place it in a container with fuel, pull the RTV out the following day and you'll see why

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The intake flanges are often overtorqued, don’t align correctly, or can be bent. I have had good luck filing the ears of the retainer flush. Also, many times the flange doesn’t seat into the grove and is not flush. As a last resort use RTV to hold the gasket in place. Try and use something that doesn’t dry like halomar etc. The lock washers tend to work loose as well, or maybe the gasket just compresses enough and things get loose over time.  I’ve used double gaskets in the past but it was for a fire-breathing  390hp EXP540. 
-Matt

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12 hours ago, MB65E said:

The intake flanges are often overtorqued, don’t align correctly, or can be bent. I have had good luck filing the ears of the retainer flush. Also, many times the flange doesn’t seat into the grove and is not flush. As a last resort use RTV to hold the gasket in place. Try and use something that doesn’t dry like halomar etc. The lock washers tend to work loose as well, or maybe the gasket just compresses enough and things get loose over time.  I’ve used double gaskets in the past but it was for a fire-breathing  390hp EXP540. 
-Matt

Thanks for the info.

Currently my #2 has 2 gaskets AND RTV just so I can do some run-ups and see if it solved the problem.  Now that I know it does I need to get it fixed correctly.  Before I perform something that is unrecoverable like filing, I'm going to get buy in from my A&P.  Its getting a new surefly (left) next week and the right mag is getting sent for overhaul so the plane will be grounded for a bit and he can take a look.

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19 hours ago, RLCarter said:

the 2 surfaces (intake pipe and cylinder) should be parallel to each other, I'm not a fan of RTV used were fuel is present. Get a dab of RTV and let it cure, then place it in a container with fuel, pull the RTV out the following day and you'll see why

yea...  The RTV was more of a testing aid.  I had a feeling it wouldn't be smart to leave it there.  Once I talk to my A&P, we will remove it and fix it correctly.

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