Ejected spark plug

[RJR49 129]

A new Head Gasket is on order. I'll check the points, and valve clearance before I put it back together. NAPA doesn't have the Helicoil kit but there's an AutoZone nearby. Back to Ebay if they don't have it. FYI NAPA wanted $23.00 for the gasket and $27.00 for shipping. Ebay was $13.00 including shipping. They claim genuine Kohler. We'll see.

[ranger 1,756]

I think inserts are preferred over “Hellicoils” for spark plug thread repairs because of the reduction of heat transference from the plug to the head, leading to the plug running too hot. Perhaps the use of stainless steel for the Hellicoils doesn’t help. One ‘Recommendation’ when they were used as repairs to auto engines, especially if driven hard, was to fit the next grade colder plug to that particular cylinder. Apparently fitting an insert didn’t carry the same risk! 

 

[WHX?? 48,833]

1 hour ago, RJR49 said:

NAPA wanted $23.00 for the gasket

Agreed NAPA has been bending me over for seals lately too but they ain't exactly known for their small engine parts.  13 is a good price for an oem Kohler if it has the fire ring. 

[RJR49 129]

I guess it could be on the lean side. It has a Chinese carb on it. I opened both screws 1 1/2 turns. It starts so quickly, and runs so well that I didn't make any other  adjustments.

[Snoopy11 5,714]

16 hours ago, Bill D said:

wondering about the knocking you heard before the plug let go

Precisely my biggest concern.

 

Don

[Tractorhead 9,064]

13 hours ago, ranger said:

I think inserts are preferred over “Hellicoils” for spark plug thread repairs because of the reduction of heat transference from the plug to the head, leading to the plug running too hot. Perhaps the use of stainless steel for the Hellicoils doesn’t help. One ‘Recommendation’ when they were used as repairs to auto engines, especially if driven hard, was to fit the next grade colder plug to that particular cylinder. Apparently fitting an insert didn’t carry the same risk! 

 

 

I used the Helicoils even on my KTM Racing Engine with no Troubles preventive.

 

I don‘t know what inserts you mean, so a closer info is very Welcome about that.

after i inserted the Helicoils the Sparkplug never made any troubles or even missfires.

Also in hard Racing conditions i never had Troubles with them.

 

But however if you have closer info‘s about for me - thanks in advance.

 

 

[RED-Z06 2,221]

Either loose plug or over tightened last time and pulled the threads, see both alot, from saws to cars, and everything inbetween, i don't even typically pull the heads to fix it, i make sure the piston is down, grease up the thread resizer, go about half and pull it out, brake kleen it then grease it again then finish...put the insert in, set it with a hammer and put in a new plug. Valves, running rich or lean...won't cause this.

[Snoopy11 5,714]

17 hours ago, RED-Z06 said:

i don't even typically pull the heads to fix it

I don't recommend this method. Any little metal flake can go down into the piston, and scar the cylinder wall. Then you have much bigger problems. Not worth the risk.

 

17 hours ago, RED-Z06 said:

Valves... won't cause this

I beg to differ. Ask any mechanical or performance expert, one of the causes of spark plug blowout (ejection) is excessive cylinder pressures which are caused by valve train mechanical issues... (i.e.) exhaust valve not opening adequately. Ordinarily, it happens when engines are at operating temp and at full running governor RPM. Yes, it can cause this.

 

I haven't personally ever used heli-coil fixes. I have always seen it as more of a ghetto bandage. I usually buy new cylinder heads if anything happens to the spark plug threads, if possible. However, if the other engine guys on the forum say that the heli-coils work, I stand behind that.

 

Don

[lynnmor 7,310]

4 hours ago, Snoopy11 said:

I haven't personally ever used heli-coil fixes. I have always seen it as more of a ghetto bandage. I usually buy new cylinder heads if anything happens to the spark plug threads, if possible. However, if the other engine guys on the forum say that the heli-coils work, I stand behind that.

 

 

I did a fair amount of work for NASA in my shop.  Every tapped hole in anything had to have Heli-Coil type of inserts.  If it is good enough to go to the moon, it will be good enough for your tractor.

[RED-Z06 2,221]

4 hours ago, Snoopy11 said:

I don't recommend this method. Any little metal flake can go down into the piston, and scar the cylinder wall. Then you have much bigger problems. Not worth the risk.

 

I beg to differ. Ask any mechanical or performance expert, one of the causes of spark plug blowout (ejection) is excessive cylinder pressures which are caused by valve train mechanical issues... (i.e.) exhaust valve not opening adequately. Ordinarily, it happens when engines are at operating temp and at full running governor RPM. Yes, it can cause this.

 

I haven't personally ever used heli-coil fixes. I have always seen it as more of a ghetto bandage. I usually buy new cylinder heads if anything happens to the spark plug threads, if possible. However, if the other engine guys on the forum say that the heli-coils work, I stand behind that.

 

Don

Most heads are aluminum, most cylinders are iron/steel, you arent going to get a scar from a softer metal..remember that the rings are steel, and the aluminum already run up and down the bore...it'll be fine, its the standard fix for 4.6/5.4 fords that were known to blow plugs out.

 

Helicoils are a proven repair if done right, if you arent experienced enough to do them then i understand your reluctance to stand behind them but don't put down something you dont know much about.  Ive fix stripped bar studs on saws, head bolt holes, plug holes, cylinder holes on saws, there's not much you cant fix with a helicoil/insert..in fact in some instances a helicoil is a preventative fix for bad designs...32v Northstar V8s had porous block castings and the head bolts would pull if it got hot...the fix is to drill the block and put in a timesert or keensert..the insert bites the block and prevents the bolts from pulling during torque down because the friction is on the insert.  

[RJR49 129]

"Exhaust valve not opening adequately. "I haven't checked the clearance but the exhaust valve looks pretty good to me

[RJR49 129]

It occurs to me that I might have a weak valve spring. I don't have a way to accurately test spring tension Later today I'll try, but I'll go out later today and compare the pressure it takes to push it down to the tension on thebintake valve

[Snoopy11 5,714]

18 hours ago, RED-Z06 said:

it'll be fine

Not trying to split hairs or scratch lilies here... but I must disagree.

 

First of all... @RJR49 already has the cylinder head off... so it seems like he knows what he is doing. Moreover, while you may not pull the heads, pulling the heads before installing a thread insert is inarguably the best policy. There are other methods, which I will mention here... but from an engine builder standpoint... my analysis is going to be much different.

 

If your heads are still installed, you can apply grease to the tools you are using to catch the shavings using white lithium grease. This isn't going to stop/catch all the shavings, but it is better than doing nothing.

 

You say that this is the standard fix for a couple of Ford Engines. Further, you present that shavings and chips going into an engine is no big deal... Well... I outright knew this was wrong... but I'll pull a source just to prove it. Ford says:

 

CAUTION: Ford Motor Company recommends removal of the cylinder head to avoid chip contamination in the engine.

 

CAUTION: If spark plug thread repair is being done in vehicle make sure the piston is 1/3 - 1/2 way down the bore on the down stroke. This will ensure the valves are closed to help reduce contamination... Note: If procedure is being done in vehicle clean hole using a vacuum cleaner to remove debris.

 

Lastly, it was not my intention to  "put down" thread inserts... rather, from an engine building standpoint, I personally tend to replace cylinder heads rather than fix them. What I will never do is work on a cylinder head... allowing shavings to go into the engine...

 

Don

 

[RJR49 129]

My Guru says. Vacume, or blow out with air pressure, then use a magnet on steel heads. Personally, I've always pulled the head. On a one lung Kohler its a no brainer. On my fathers 1962 Buick Special 215 CI aluminum V8, more effort. But, Still worth it. Of course my labor doesn't cost.me $120.00+ / hr

[RED-Z06 2,221]

3 hours ago, RJR49 said:

My Guru says. Vacume, or blow out with air pressure, then use a magnet on steel heads. Personally, I've always pulled the head. On a one lung Kohler its a no brainer. On my fathers 1962 Buick Special 215 CI aluminum V8, more effort. But, Still worth it. Of course my labor doesn't cost.me $120.00+ / hr

Steel/iron head id give a strong thought to pulling the head, but aluminum...if i dont see any other reason to, probably not.  Flathead briggs twins had a bad habit of building up carbon, when those come in with stripped plug holes i pull the heads to scrape the carbon because its probably never been done.

 

Just never been a big fan of pulling heads unless necessary, always a chance of pulling threads on a head bolt or causing head gasket problems...opening a can of worms 

[Snoopy11 5,714]

4 hours ago, RJR49 said:

Personally, I've always pulled the head

You definitely sound like you have a good grasp on what you are doing! Good job! Anyone doing this should follow your example.

 

Keep us posted!

 

Don

[RJR49 129]

Don, thanks for the complement. I hope I deserve it. Another thought. The inserts were either to short, or to long. I didn't feel comfortable with either configuration. The short one not having enough threads, and the long one, either hitting the piston, shielding the spark, or burning the part sticking below the head.  so I cut the long one flush with the head. One question. I used 400 grit emeroy cloth on a granit block to flatten the head. That took forever. 220 took less time but I didn't like the finish. Any thoughts?

[RED-Z06 2,221]

11 minutes ago, RJR49 said:

Don, thanks for the complement. I hope I deserve it. Another thought. The inserts were either to short, or to long. I didn't feel comfortable with either configuration. The short one not having enough threads, and the long one, either hitting the piston, shielding the spark, or burning the part sticking below the head.  so I cut the long one flush with the head. One question. I used 400 grit emeroy cloth on a granit block to flatten the head. That took forever. 220 took less time but I didn't like the finish. Any thoughts?

How warped,  if its bowed up pretty badly, start with a few passes of 180 or 220 then move to 320, i like a bit of a rough finish to assist in biting the gasket, its just really important you keep rotating the head to keep from planing it at an angle 

[RJR49 129]

Thanks for the "atta boy" I hope I deserve it. Another thought. The inserts were either to short, or to long. I didn't feel comfortable with either configuration so I cut the long one flush with the head. 

 

The points are open .026. That's a little over the .020 (fig 1-5 in the Kohler engine manual). But I'm not sure if .006 is negligible or if it represents a 30% error. Or, how bad that screws up the timing. 

[RED-Z06 2,221]

1 hour ago, RJR49 said:

Thanks for the "atta boy" I hope I deserve it. Another thought. The inserts were either to short, or to long. I didn't feel comfortable with either configuration so I cut the long one flush with the head. 

 

The points are open .026. That's a little over the .020 (fig 1-5 in the Kohler engine manual). But I'm not sure if .006 is negligible or if it represents a 30% error. Or, how bad that screws up the timing. 

You can put it at .020" and see how it runs, some engines the points gap is gospel but Kohlers...some like a bit more, some a bit less.  .026 is quite wide

[RJR49 129]

Parts finally came in. New credit card. Kohler dealer didnt bother to call and tell me the old card got rejected? Called them to ask WTF! When a week went by and nothing arrived. BTW bought from Kohlers website and the parts come from.the local dealer. Surprisingly, the parts (gaskets, & points. No mechanical parts) were no more expensive than after market)? Anyway, I described the problem to a friend who's an aircraft A&P. He thought "maybe" the problem is the crankshaft rod bearing. He said the noise is obvious. Maybe to him! Anybody experienced that condition? Once I get it back together we'll see. But, if I still hear the knock I guess its a teardown. Hate to think of the piston exiting the block sideways.

[Snoopy11 5,714]

11 hours ago, RJR49 said:

crankshaft rod bearing

One test is to take the crankshaft in your hand, and try to move it up and down, side to side to see if there is any movement. If there is any play in the crankshaft... you need new bearings.

 

That doesn't always tell you for sure if you need new bearings, but... it is something to try...

 

Don

[Bill D 1,926]

Something else to consider is balance gear failure.  That will cause a knocking sound when running.  If that is the case, plan to rebuild the engine.  Send the crank out to be balanced and eliminate the balance gears.

[RJR49 129]

I hate to embarass myself this way but I didn't take a picture before I disasembled everything. I believe I have it right but confirmation would be appreciated. The throttle is closed in ..58 and open in..11

[RJR49 129]

Just keeps getting better. Tried toTorque the spark plug to 19 ft/lbs and stripped the insert! I thought it was pretty loose going in. Apparently, I side loaded the tap and oversized the threads. Search for a new head and very disappointed to learn that they don't make them anymore.