Spark Plug Stripped, Repair Stripped

[mike-s]

I'm now back to doing my own oil changes after having to repair stripped oil pan drain plugs and having to chisel off the oil filter ring.
Can you imagine having them Bubbas to these repairs that they screwed up in the first place????

Even when under warranty, I've always done my own work, because taking it back for a re-do is a waste of time, if they don't screw it up worse. At least for non-major repairs. After warranty, tire install/balancing is the one thing I leave to a shop, because it's pretty hard to screw up and buying the right tools would be hard to amortize/justify.

 

[Ando81]

So after an hour of struggling removing the engine and cylinder, I found that the original thread repair insert has been installed cross threaded. I installed a better quality insert and slightly angled it further towards the top of the engine and it’s tightened up firm. The insert seems to be really flush fitting against the cylinder thread. Maybe I can throw new crank seals on it and put it back in. Is there anything else I should check whilst I’m there?

 

[HarleyT]

I was wondering this, if I’m going to the trouble of getting this cylinder off should I put a bigger piston and cylinder on it. Would it fit up to the bottom end the same?

The 029, 039, MS290, Ms310, Ms390 are all the same saw, pretty much, except for the piston/cylinder size, everthing will bolt up fine.

 

[Ando81]

I think I’ll keep it as it is. The piston and cylinder have done very little work by the looks of it. Thanks for everyone’s input though.

 

[lone wolf]

I think I’ll keep it as it is. The piston and cylinder have done very little work by the looks of it. Thanks for everyone’s input though.

Pressure test the repair.

 

[Ando81]

Pressure test the repair.

Is there a diy way that I can test it without a pressure tester?

 

[lone wolf]

Is there a diy way that I can test it without a pressure tester?

Alcohol in the cylinder uspidedown with the spark plug in and see if it holds for a minute or so,but not the method I recommend a pressure test is best.

 

[rupedoggy]

Put some soapy water around the area and pull the rope a few times

 

[Ando81]

Ill be trying something to test compression before I go to the trouble of installing it completely back into the saw. Thanks for the tips.

 

[RED-85-Z51]

When i bought my 94 Sierra it had a GM Mr Goodwrench Crate 350 in it with paperwork...under 100 miles on the engine..i pulled the valve covers and verified it was all new.

Year later im doing plugs and 2 drivers side plugs came out with inserts on them. Verified the heads were new castings not remans. All i can figure is the shop that did the engine install put new plugs in with an impact...i mean...iron heads.

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[Okie]

When i bought my 94 Sierra it had a GM Mr Goodwrench Crate 350 in it with paperwork...under 100 miles on the engine..i pulled the valve covers and verified it was all new.

Year later im doing plugs and 2 drivers side plugs came out with inserts on them. Verified the heads were new castings not remans. All i can figure is the shop that did the engine install put new plugs in with an impact...i mean...iron heads.

Sent from my LM-G820 using Tapatalk

You need to think about doing something to lock the insert into place after you have pressure tested and keep a heads up and do not overtorque the spark plug or the insert may lock (will lock) onto the plug's threads and come out again.

 

[lone wolf]

Ill be trying something to test compression before I go to the trouble of installing it completely back into the saw. Thanks for the tips.

Mount the cyl on the saw without installing the piston and pressure test it ,borrow or buy one if you dont have one.

 

[Vintage Engine Repairs]

I’d be really interested in learning more about welding and re drilling. I’d assume the person welding would keep away from the very surface where the plug butts against the cylinder - getting that dead flat to seal against the plug may be tricky otherwise I’d imagine?

 

[lone wolf]

I’d be really interested in learning more about welding and re drilling. I’d assume the person welding would keep away from the very surface where the plug butts against the cylinder - getting that dead flat to seal against the plug may be tricky otherwise I’d imagine?

Yes it has to be very dead on to seal.

 

[rupedoggy]

Not to tricky Tom. They make special machine tools for that.

 

[Matt Coolen]

I tried the keen-sert in an MS362, no luck. Went in fine and was able to peen the knurls in properly, but only held until the saw got hot. I attributed it to the steel insert and the aluminum cylinder expanding and contracting at different rates. Whacked a new cylinder on it and sold the saw....which i regret. That saw worked guuud.

 

[ironman_gq]

I tried the keen-sert in an MS362, no luck. Went in fine and was able to peen the knurls in properly, but only held until the saw got hot. I attributed it to the steel insert and the aluminum cylinder expanding and contracting at different rates. Whacked a new cylinder on it and sold the saw....which i regret. That saw worked guuud.

Had an 044 do that, I fixed it by installing the plug loosely and getting the saw up to temp then I removed the plug and peened the insert again. Hasn't moved in almost 10 years.

 

[L34]

I used an aluminium insert.
Are yours the knurled edge or 4 key One?
I used the 4 key One.

 

[mike-s]

I've always had good luck with Time-sert solutions. But, unless you can borrow the tooling, it's expensive for just repairing one thread.

 

[Ando81]

I used an aluminium insert.
Are yours the knurled edge or 4 key One?
I used the 4 key One.

The one I used was a thicker aluminium but unfortunately didn’t have any knurled edge. I fitted a generous amount of thread locking compound but I’m thinking that the compound may not tolerate the combustion chamber heat so it may have been a waste of time.