Stripped Thread on Honda HRX217HXA Block

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Tonight I was adjusting the idle speed on my HRX217HXA because on low speed it was way too low. I have a Sendec hour meter / rpm guage and it was idling in slow at about 1200 RPM. It was hard to get in even with a longer screwdriver to adjust the carb but I got that dialed in perfect and only burned my finger once as the mower was up to operating temps. In the process, I knocked the breather hose off the back of the air cleaner housing and could not get it back on. I had to loosen the bolts for the air cleaner housing, and the throttle control bracket in order to get enough room to put the hose back on. When I tightened the bolts back down, I followed the torque spec per the shop manual I have for the mower, which is 7.2 ft lbs. All 3 inside the air cleaner tightened down normally to spec, but the one below decided to strip out. It happened so fast it was too late to "stop". The bolt will still get "snug" but definately may work loose.

After saying a few choice words, I mowed the lawn and put it away. It's got 72.2 hours on the mower now, it's a 2007 model.

I'm a very handy guy, but I'm kind of worried that this won't be an easy fix. Has anyone ever used these Helicoil repair kits? If so, any tips?

My other thought would be to just put some loc tight on the thread and get it "snug", and hopefully it won't work out again.

I have a feeling it stripped out because the block was hot and the aluminum was softer. I should have waited for it to cool off before torquing it I guess
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Andrew

[img:left]https://docs.google.com/leaf?id=0B_RfvYn...list&num=50[/img]
[img:left]https://docs.google.com/leaf?id=0B_RfvYn...list&num=50[/img]
[img:left]https://docs.google.com/leaf?id=0B_RfvYn...list&num=50[/img]
[img:left]https://docs.google.com/leaf?id=0B_RfvYn...list&num=50[/img]
 
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Helicoils are fairly easy to use, thats the way I would do it to ensure it won't come loose. Just buy the kit and use the drill bit and tap that are in it and you shouldn't have any problems.
 
Originally Posted By: amleeling
I have a feeling it stripped out because the block was hot and the aluminum was softer. I should have waited for it to cool off before torquing it I guess
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That may have been a factor. Aluminum also galls very easily if the threads are not lubricated, and they may have not been lubricated from the factory. Use some anti-seize on them in the future.
 
Appreciate the feedback! One question - after I do the Heli-Coil, should I avoid tightening to torque spec? Not sure if that might be too risky even if I do it with some anti-sieze and when the block is cold.
 
helicoil type repairs are stronger than original because the threaded area is greater . Use the original recommended torque compensating for the lube used on the threads . Aluminum is easy to strip. It just happens.
 
All torque values are ft lbs in the shop manual. The hour meter / tach has a single wire which runs down to wrap around the spark plug wire. I attached it to my control cover as pictured in my photos above with 3M heavy duty red double sided tape. (Didn't want to screw into the cover).

The meter shows engine RPM while the engine is running, and when it's off it displays the total operating hours.

Andrew
 
What I've read is Helicoil works fine in iron or steel, while Time-Sert is better for Aluminum.
In limited practice I've had a Helicoil come out of Aluminum (it took Aluminum threads with it, looking like a coil or a spring). I haven't had problems using Time-Serts. Also, the Helicoil needs more depth than a Time-Sert does.

You can try a Helicoil first as it's cheaper, and, I think for the same size fastener if the Helicoil fails and you go to a Time-Sert you'll have to remove a little more metal. Just treat the Helicoil gently, and make sure you have enough depth for the entire Helicoil before you drill.

Also, that "happened so fast it was too late"? That's what Aluminum is like. It's crystalline. There's no elastic point before failure. I use a 1/4" torque wrench made by Utica for low torque like 7.2 lb-ft.
 
The picture does NOT look like a 1/4 inch lb-inch torque wrench. It is NEVER a good idea to use 3/8 inch ft-lb(5-80) at it lower end.

- Vikas
 
I got the bolt hole fixed - was super easy :) I just have to order new gaskets and a spacer that developed a crack. I know they say you should replace the gaskets everytime you remove the carb anyway, and it's a good thing I found the cracked spacer. It was probably letting a bit of air through it, which could of explained why my idle speed was all jacked up. Also it would have let unfiltered air into the engine, probably not much but still glad I caught this when I did. Will be another weekend without mowing, oh well
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Links to pics below:

https://docs.google.com/leaf?id=0B_RfvYn...Jk&hl=en_US

https://docs.google.com/leaf?id=0B_RfvYn...kz&hl=en_US

https://docs.google.com/leaf?id=0B_RfvYn...Iw&hl=en_US

https://docs.google.com/leaf?id=0B_RfvYn...I2&hl=en_US

https://docs.google.com/leaf?id=0B_RfvYn...c3&hl=en_US

https://docs.google.com/leaf?id=0B_RfvYn...ky&hl=en_US

https://docs.google.com/leaf?id=0B_RfvYn...E1&hl=en_US

Andrew
 
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While this reply is a little late to be of help, you could have saved the money on the heli coil and just drilled and taped for the next size up bolt.
 
I would have just filled the hole with JB Weld, re-drilled and tapped to original size. JB Weld is fantastic stuff. I've made fixes with it that have astounded me. It's incredibly resilient and durable.
 
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