O&R Engine rebuild pics

[factory 487]

On 4/6/2017 at 3:10 AM, Oldjimturbine said:

I would like to know if there is any easy way to move the exhaust to install a fuel tank.  The exhaust and cylinder head won't budge.  Is there something I have to remove first?

 

If the exhaust collector will not move, the cylinder will need to be unscrewed. But make sure the piston is free to move before trying this, as the con-rod will break if the piston is stuck.

 

The engine maintenance manual gives details on making a cylinder removal tool.

The instructions given are to make it from a piece of flat steel 3/16" thick & 1" square, with a hole drilled in the middle for using a screwdriver as a "T" handle.

 

I made one from a piece of steel & bar found in a box of offcuts & salvaged bits in the shed. I didn't bother to make it 1" square though, I only squared up the ends and drilled the hole for the bar.

If the cylinder is very tight I usually use a vice to hold the engine crankcase (use wood or similar to protect the engine from the vice jaws) and use an adjustable spanner to turn the tool. You will probably need to replace the gaskets if you remove the cylinder to prevent leaks. Also make sure that the slot in the top of the cylinder lines up with the crankshaft or is at 90 degrees to the crankshaft when reassembling.

 

Here is a picture of the cylinder removal tool I made.

 

David

[CNew 404]

On 1/14/2015 at 1:14 AM, Wallfish said:

[snip]

 

Then decided to replace the crank seal in the induction part. Had to pick the old one out with a small dental pick tool

 

 

 

I just worked on an engine that had the induction shaft seal installed with the grooved side of the seal facing out away from the engine. Was this incorrect?  It looked to be the original seal.  I’m also a little confused about if the induction side of the engine is pressurized or if it creates a vacuum and sucks air.  I’ve read multiple instances where people report oil and grease from gear boxes being sucked into the engine when the induction shaft seal fails.  If this is true it would seam to me that the induction housing and seal are maybe under sort of a vacuum. Am I misunderstanding how this is supposed to work? Has anyone else come across a seal with the grooved side facing away from the engine?

Edited July 8, 2019 by factory
Edited quoted post for relevant part.

[factory 487]

Looking at the service manual, it looks as if the open-end of the induction seal should face towards the "small end of the induction case" i.e away from the engine, as you've found it. The feather valve seal is fitted the opposite way around.

 

 

I will check the one NOS induction casing I have, as the seal is pre-fitted.

 

If any seals are bad they will leak whichever way round they are fitted.

 

David

[factory 487]

Here are some pictures of the seal fitted to the NOS induction housing I have.

 

 

David

[CNew 404]

Thank you David!  That looks like the grooved side of the seal is facing out away from the engine.  

 

I just finished opening up the engine again and flipped the seal around. I’ll see if there is any noticeable difference in how it runs.

 

Thanks again for all the help!

 

Clint

Edited July 9, 2019 by CNew
Updated comment

[Mantiscia 0]

Wallfish, Thx for the pic! This looks just like the gearbox on the engine i just bought. But mine does not have #21. Is #21 a pin of some sort? Thx!

[factory 487]

Part #21 on that diagram is a screw, this is used on earlier engines with a tapered output shaft, later engines use a D shaped shaft for the clutch assembly.

 

David

[jlhausmann 0]

Wallfish,

What is the safest way to remove the flywheel and not damage it? I have a Tiny Tiger generator with no spark and I need to figure out why, thanks!

Edited December 1, 2022 by jlhausmann
Misspelled

[CNew 404]

18 hours ago, jlhausmann said:

Wallfish,

What is the safest way to remove the flywheel and not damage it? I have a Tiny Tiger generator with no spark and I need to figure out why, thanks!

i usually just loosen the flywheel nut and unscrew it until it’s about flush with the end of the threaded shaft. Then give it a sharp tap with the end of a wrench (or very small hammer) and it always pops right off. The rapid shock from the impact is what loosens it from the tapered shaft. You really don’t have to hit it very hard, more of a firm tap.

[jlhausmann 0]

3 hours ago, CNew said:

i usually just loosen the flywheel nut and unscrew it until it’s about flush with the end of the threaded shaft. Then give it a sharp tap with the end of a wrench (or very small hammer) and it always pops right off. The rapid shock from the impact is what loosens it from the tapered shaft. You really don’t have to hit it very hard, more of a firm tap.

Thank you. I was able to get it off with a puller after modifying the puller. The reason I had it apart was it had no spark. I filed the points, set them at .020 and the magneto to flywheel gap was correct at. 010. I still have no spark. Are there coils and condensers available anywhere? Thank you for your help. 

Edited December 2, 2022 by jlhausmann
Word misspelled

[CNew 404]

There are a couple used coils and condensers on eBay right now.

 

when you checked the spark after cleaning and setting gaps did you put the starter housing back on and pull the rope or did you just turn the flywheel by hand to check for spark?  I’ve had engines where if I used the starter rope it helped turn the flywheel fast enough to get spark whereas if I just tried to spin the flywheel by hand nothing would happen. 
 

also, when you cleaned the points did you clean the little posts they fit on?  I’ve had cases where the slightest corrosion or oil on the little posts messed up the spark.

[jlhausmann 0]

3 hours ago, CNew said:

There are a couple used coils and condensers on eBay right now.

 

when you checked the spark after cleaning and setting gaps did you put the starter housing back on and pull the rope or did you just turn the flywheel by hand to check for spark?  I’ve had engines where if I used the starter rope it helped turn the flywheel fast enough to get spark whereas if I just tried to spin the flywheel by hand nothing would happen. 
 

also, when you cleaned the points did you clean the little posts they fit on?  I’ve had cases where the slightest corrosion or oil on the little posts messed up the spark.

No I did not,  but I will try both of your suggestions. I really appreciate your help. 

[Wallfish 698]

22 hours ago, jlhausmann said:

No I did not,  but I will try both of your suggestions.

Yes, clean the post and the copper points spring for that connection. All wire connections too. It's not common for a coil to fail unless damaged but it's possible. Condenser is a possibility.

I also tap the nut on the shaft to remove flywheels

[brad2921 0]

Where can I find a cylinder o-ring and rubber manifold gaskets for the bottom of the cylinder?

[Wallfish 698]

10 minutes ago, brad2921 said:

Where can I find a cylinder o-ring and rubber manifold gaskets for the bottom of the cylinder?

Re use them if possible. I've reused many without issue if they were not damaged

If they were damaged, search "High Temp gasket material" to cut your own. The O ring isn't anything special and can be found with a search for that size as well