Installing valve keeps

[inairam]

From a compression check on my '49 I saw #3 was low. after pulling the value cover plate I saw one of the springs was cocked a little. After some probing with a screw driver I saw the was only one keep. I was messing with this one and off for a few weeks. I bought a new tool ( the big "c" shaped tool) and an old flat head tool from ebay. I just can not figure out how to keep the sping up and and put in the keeps. I have been reluctant to pull the head up to this point. Any suggestions?

[Larry in WNY]

You need a small engine valve spring compression tool from Napa. It will just fit within the space to get the springs compressed. The large C type is for larger engines and those with overhead valves.
Larry

[ScottyD'sdad]

You have to pull the head, to replace the keeper. The top of the clamp pushes down on the top of the valve, and the bottom, pushes up on the spring. The bottom of the clamp has to be shaped correctly, to fit in and lift the spring. The Craftsman one, has the right shaped spring lifter. While the head is off, I'd recommend cleaning and lapping all the valves, since it probably wasn't done since Eisenhower was president.
Ed

[Eugene]

The big C shaped tool, valve spring compressor, may or may not work. If the frame is to tall, use some wood blocking on the top of the block.

We use to change valve guide seals by putting the cylinder to TDC then applying 120 lbs air pressure to the cylinder - spark plug adapter. Air pressure kept the valves closed while removing the valve actuating mechanism and replacing the seals.

Never tried it on a Cub. Might work if you have the small, correct, valve spring compressor.

[inairam]

I used Clothesline line rope in the spark plug hole to hold the valve down and this tool. The top and bottom can be independently adjusted for width. There was a member who recommended grease to hold the keeps in place and on the screwdriver to place the keeps. Great tip. I first adjusted the values to .013 per manual and after more reading of old posts re adjusted to .015. Another compression check and number three is still low but now I know it is not the valves.

[ScottyD'sdad]

Could still be the valves, causing the low compression. May need to be lapped, or even ground, to get a good seal. I recommend a valve job, on almost every cub, since it was last done, during the 60's, or maybe the 70's. I've seen some pretty rough looking valves and seats.

Ed

[inairam]

Do you think I should replace the valve train ($140 hamilton bob) or just relap #3?

[ScottyD'sdad]

Do you think I should replace the valve train ($140 hamilton bob) or just relap #3?

Can't tell without seeing it. That valve and guide could be worn unevenly, from (who knows, how long) running with uneven pressure on the spring. I'd lap all the valves, since the head is off, at a minimum. Real answer depends on what you find.
Ed

[Eugene]

Agree with Ed.

My opinion. In addition to a valve job, I would put the engine on the bench and plastigage the bearings, measure pistons and bore. Might as well spend more money and time, and end up with a rebuilt engine.

[KETCHAM]

$$$$$$$$$$$$$$$$$ HOW DOES IT RUN???? If it runs good...leave it alone or wait till winter for a tear down....You can spend a lot of $$$$ real quick...compression test??? weak valve springs??? Time and money....on a rebuild...Kevin

[inairam]

the other cylinders were about 100 to 110. it felt weak this spring which is when I found the keep was missing on the #5 valve. on cylinder 3. I am not sure a complete rebuild is warrented

[ScottyD'sdad]

If you have decent oil pressure, and are not burning excessive oil, I'd go with the valve lapping. I try to keep my fleet running, without spending thousands. If it has enough power to do what we need it to do, it's out in the work force. When it can't hold up it's end of the bargain, then it gets a rebuild. Most of my tractors were in the $500 range, so they need a wide range of service, before going to work.

Ed

[Matt Kirsch]

Even with all of this it won't hurt a thing to get the correct small engine valve spring compressor, put the keeper back in, and give it a spin to see if that fixes your compression problem.

If it does, it saves you a bunch of work. If it doesn't you're only out the cost of the tool and the keeper.

[inairam]

I got the tool and the keeps are back and all of the valves are adjusted to 0.015 and that is when I did the compression check

[Winfield Dave]

I first adjusted the values to .013 per manual and after more reading of old posts re adjusted to .015. Another compression check and number three is still low but now I know it is not the valves.

What is low?