View Full Version : Way O/T

01-02-2010, 11:54 AM
I have a Toy built tiller that is so old that it doesn't even have a serial number on it. It was passed onto me from my father.

Here's the issue'; To my knowledge, the head has never been removed since manufacture and now I've a blown head gasket. I'm primarily concereed about the head bolts and I'm concerned in terms of the head bolts and not to either strip them or worse yet break them over.

I've been hitting the head bolts with both PB Blaster as well as Kroil, yet me head bolts just won't budge.

Advice from anyone is sincerely appreciated.

01-02-2010, 12:23 PM
In many cases, rusted bolts can be convinced to break loose by a sharp rap with a hammer on the head. I can't say that this will work on head bolts that are torqued to spec but on general stuff it works well. I had an exhaust bolt on a lawn mower engine that was rusty and tapped into an aluminim casting. I soaked it with Kroil and gave it a couple of whacks with a hammer and it let go with only a little struggle. Best of luck with it.

01-02-2010, 12:40 PM
Hmm, Troy Built tillers are good. Is it an old Briggs & Stratton cast iron engine?

Anyway, using a penetrating oil and heat may get them loose. Just heating up the cap of the bolt will help. Putting a flat faced punch on the head of the bolt and hitting it a time or two will help. Do those for a week or two and keep testing to see if they free up don't get in a hurry you have to let the penetrating oil seep into the threads and that takes time. When you put them back use anti seize on them.

Your Old Dog
01-02-2010, 12:47 PM
I'd be amazed if this wouldn't do it. It's the kind of hand impact wrench used on motorcycles. Should be 1/2 drive and will fit your socket set. Very handy tool to have in your drawer. If you're not familiar with them, you whomp on the blunt end with a small sledge hammer and it jars the bolt loose. Usually about $15.00 I think.


01-02-2010, 12:52 PM
Does it look like this?

circa 1937

J Tiers
01-02-2010, 03:44 PM
The problem is that the actual threads are nowhere near the head of the bolt, so the penetrating oil isn't getting on them. The thickness of the head is in the way, so penetrating will be painfully slow.

You might get better results by carefully digging away the gasket from the side of as many bolts as you can, and hitting them THERE with the oil. Might not work on some gaskets, and you don't want to burr up the surfaces.

Even starting the oil in from the side might make it work faster.

heat helps, if it runs you can heat it up by running.......... and then hit the heads of the bolts with extra heat

01-02-2010, 04:02 PM
Just had a similar problem with a Tech engine.

Rocky's struggle (http://bbs.homeshopmachinist.net/showthread.php?t=38425)

The head bolts pass out the bottom just a bit (between the cooling fins) and pick up all sorts of crud and rust. Those that didnt pass through the bottom were close and rusted anyway.

Only two of the bolts I was removing stopped part way up. And I hat to say it but they tore the threads the rest of the way up. I drilled them threads out and put helicoils in. Then, because of the gasket failure that I had, I checked the head for warpage and found some. After I worked that out, I reassembled and it is working fine.

Try the Jtiers method to start and see what you get. Clean out the cooling fins and look closely between them. You may see the bolt ends hanging out or even see the bottom of the holes for them. Put liquid penetrate there as well.

Good luck.


01-02-2010, 04:15 PM
Try taking the spark plug out, cranking the piston over to TDC and shoot some PB Blaster into the chamber. It'll get it closer to the threads than putting it on from the outside. Still might take a while....


Rookie machinist
01-02-2010, 07:02 PM
I have used an air chisel with a blunt end to vibrate stuck bolts. Hold the chisel tight to the bolt and lightly vibrate it for a minute or two it has worked good for me in the past.

01-02-2010, 07:24 PM
you can also use and impact gun set it at 1 then work your way up as needed, same idea as the hammer impact tool that your old dog posted ,

01-02-2010, 07:36 PM
If you can't get the bolts loose and don't want to strip the threads, try cutting off the bolt heads with an abrasive cutoff tool (mine uses 3" disks) to remove the cylinder head. Then, place a nut over the stub of the bolt and weld it on. Let it cool, and wind out the bolt.

The heat, then contraction breaks the rust loose. I've never had this method fail to remove a broken-off bolt or stud. By cutting off the bolt head, you're ahead of the game because you have a good stub sticking up to weld to.

Don Young
01-02-2010, 10:01 PM
I have gotten an awful lot of such bolts loose by a combination of long-term soaking with penetrating oil (I like Kroil), heat and shock. It seems crude but a heavy drift and a hammer as big as you can swing easily will nearly always do the job. Don't just rap on it, hit it like you are trying to drive the bolt into the head! An air hammer also works good if you can keep it pressed hard on the bolt head. This seems to literally compress the metal to allow the shock to loosen the locked threads far below.

A hammer operated impact driver helps, especially if you put a nut in the socket so the hammer blow is transmitted to the bolt head. Be sure to use a good fitting six-point socket to help prevent rounding the bolt head off.

01-03-2010, 09:29 AM
I appreciate all the feed back Guys. When I looked at my original post, I was appalled with my spelling. Just goes to show that when one has the flu that it's probably not the best time to tackle some things.

01-04-2010, 12:35 AM
Mess with a lot of old hit & miss engines, flathead Fords ect. What works and has never failed me is heat the bolt with torch then apply candle wax to head of bolt. For some reason the heat wicks the wax into the hole and the threads, lubing the threads and allowing you to back the bolt out.


People say I'm getting crankier as I get older. That's not it. I just find I enjoy annoying people a lot more now. Especially younger people!!!

1937 Chief
01-04-2010, 01:53 AM
Are you turning the bolts the right way? (just kidding) I don't blame you for not wanting to break a bolt off in the block. It will be a real pain, but if you drill the heads off of the bolts, pry off the cylinder head you can deal with the stud that is left much better. It will probably take as much time to do that than it will be to drill out one 5/16 broken bolt. Stan

01-04-2010, 02:03 AM
Unless you are trying to restore it for some reason it will probably cost less to buy a new engine from someone like Northern Hydraulics or Surplus center.

01-04-2010, 05:58 AM
As the OP's engine is presumably air-cooled, I'd guess that there will be cooling fins on the head to contend with.

If that is the case, then cutting or grinding the heads off the bolts may not be as simple a matter as it might be if the motor was water-cooled.

J Tiers
01-04-2010, 08:55 AM
As the OP's engine is presumably air-cooled, I'd guess that there will be cooling fins on the head to contend with.

If that is the case, then cutting or grinding the heads off the bolts may not be as simple a matter as it might be if the motor was water-cooled.

Yep, that can be the case. Even when they are nominally accessible from one side.

But the other side of the coin is as someone mentioned above, a few of the bolts probably have the other end accessible because the boss has the hole drilled/threaded right through. Usually not true of a water-cooled engine.

One or two MAY actually be visible where they enter the block, sometimes a bolt or two is outside the gasket area.

01-04-2010, 11:58 AM
Spellin dont matter compooters got spell checl in em. Right>!! As for youre engine, picture removing motor from remainder of the rototiller. Container or even a 3 mil garbage bag, Stick engine in inverted (upside down) and then gill bucket pail or bag (double bag it) with kerosine. Let it sit immersed for a few days, remove engine and air impact the bolts off. Shiould work. Later clean the thereads well (aka dave cofer derusting process)or wire brush wheel anti seize them and reassemble. On seconf thought if you have a nice tree handy drain oil from engine flip rototiller upside down all together dont remove engine and hand the thing inverted over a suitable container (large rubber maid bucket) and slowly lower it into kerosine mixture. good Luck

01-04-2010, 12:36 PM
Kimfab has a good idea, 6.5 HP chicom engines go complete less fluids for less than $100 cdn. Hardly worth a complete tuneup much less major mechanical work on any small engine unless restoration is the goal.