So I picked up a Super C for cheap and looking to get it running. There was no water in the oil and the motor was free. I popped the valve cover and turned the motor to TDC and the valves were obviously misadjusted. In looking at the head and valve springs it looks like the head has has some work done as the head was very clean and the valve springs looked new. I adjusted the valved and then thought that I would check the compression and I only get 30-60 pounds. I then pumped some oil in the cylinders and the compression did not change. I then for grins backed of the valve adjustment on cylinder #4 so that the valves were always closed and the compression stayed the same. It is looking to me like it either has the wrong valves or they are not seated. I have another head that I know is good and it would be easy enough to swap but I am wondering if anyone has any other ideas before I do that. Thanks
- Thread starter Hattrick
- Start date
Owen Aaland
Well-known Member
If the valves are always closed there is no way for air to enter the cylinder so the compression will always be low.
So on this motor I am wondering how to alighn the TDC mark. I am looking at the piston at the top and the rotor pointed to #1. The mark an the crank is about 1 o"clock or a little past. Is that right? There is no timing mark that I can see. It is almost like the valves are misadjusted but I think I have them right. I am just wondering why it has not run in awhile and I am wondering if the valves are just not right or not seated.
gene bender
Well-known Member
Does it start and run? If it doesent start and run then maybe you havent set the valves correct.
Tom Fleming
Well-known Member
In addition to what everyone else has stated, if the head had a valve job done, and the valves were faced, but not lapped, it could be your problem. Could be a head gasket not torqued down properly. Have you even tried to start it?
Also, no need for a timing mark. Get #1 cylinder coming up on compression. Use a piece of stiff wire or a wood dowl in the spark plug hole on #1 to determine when the piston is on TDC. Also, you will need to get it running to do the final valve lash adjustment, as that is set "hot". What is the initial lash you set "cold"?
Also, no need for a timing mark. Get #1 cylinder coming up on compression. Use a piece of stiff wire or a wood dowl in the spark plug hole on #1 to determine when the piston is on TDC. Also, you will need to get it running to do the final valve lash adjustment, as that is set "hot". What is the initial lash you set "cold"?
Tom Fleming
Well-known Member
you may have bent push rods also............
Brownie 450
Member
Does it look like there has been work done around the front of the engine---front cover--governor area? Could be the cam has been out & got re-installed out of time.
If you're testing on a cylinder you're sure the valves are closed on, and you've got some oil in there - and you're only getting 30/40/50 psi then you're certainly leaking somewhere. at 60 you're starting to come into the "ok" range.
Somebody here mentioned that you need to let air IN to the cylinder in order for it to give you the full reading - that is true.
But if you're in doubt at least get it to it's max compression level, hold it there and watch to see how long it takes for the compression to drop.
If it stays steady for a long time, you may have less of a problem than you think.
If it does go down steadily - I agree with the other person to check the head gasket first. In doing so you can get a much better feel for the situation looking at the valves and the cylinder walls.
30 - 60 is a fairly big range. Does that mean one is at 30 and another at 60? Just curious.
Somebody here mentioned that you need to let air IN to the cylinder in order for it to give you the full reading - that is true.
But if you're in doubt at least get it to it's max compression level, hold it there and watch to see how long it takes for the compression to drop.
If it stays steady for a long time, you may have less of a problem than you think.
If it does go down steadily - I agree with the other person to check the head gasket first. In doing so you can get a much better feel for the situation looking at the valves and the cylinder walls.
30 - 60 is a fairly big range. Does that mean one is at 30 and another at 60? Just curious.
IIRC, the timing mark is on the FLYWHEEL on this engine.
There's supposedly some symbol stamped on the flywheel, and it lines up with a mark on the rear of the engine crankcase. HOWEVER, both Dad and I looked and looked and looked on his Super C, and we could not find a thing.
We ended up guessing at the timing, and got it close enough to make it run, then adjusted by ear from there.
There's supposedly some symbol stamped on the flywheel, and it lines up with a mark on the rear of the engine crankcase. HOWEVER, both Dad and I looked and looked and looked on his Super C, and we could not find a thing.
We ended up guessing at the timing, and got it close enough to make it run, then adjusted by ear from there.
It is kind of strange sometimes I get 30 on the first crank and if I keep cranking they may get to almost 60. I kind of questioned the tester so I took it over to my 100 and tested a hole and it popped to 90 right away. I afjusted the valves 15 cold. I may try and back them off to 17 and see if it makes a difference but I suspect the valves and I was even thinking like someone suggested that the cam is installed off time but it does not look like it has been apart but then again has not run in a couple of years.
Bring No1 piston near the radiator to tdc on the compression stroke. Remove the sparkplug and hold your thumb over the plug hole until you feel pressure & have a helper to hand crank the engine. Once you feel pressure drop a long plastic straw on top of the piston and you watch the straw rise while the helper slowly cranks the engine. When the straw quits rising your No1 piston should be at tdc on the compression stroke and both valves should be closed on that cylinder. Pull the distributor cap and see where your rotor is pointing. Should be at the No1 plug tower which is about 2 o'clock. Hal
teddy52food
Well-known Member
The mark is in line with a clutch pressure plate bolt. Get it close to TDC then look there. Clean the flywheel with brake clean etc.
Janicholson
Well-known Member
If it has not run in several years, get it running first. It will run with the compression it has. Then if it smokes bad after 10 hours or so decide what to do. Unless it has stripped or incorrectly installed timing gears it will run. Don't give up. Jim
So an update on this issue. I broke down and took the head off the tractor. The cylinders look good with very little ridge if any.The head gasket was coated with what looked like bathroom caulk. A white gummy coating. I am thinking that this could be the issue since I doubt that the gasket was replaced. The valve appear to be in very good condition but I have not really inspected that close yet. So would the cualk or head gasket axplain the 30ish pounds of compression? AT this point I would just like to get the tractor running. Since I soaked the cylinders with oil and the compression did not change I do not suspect the rings as the major problem at this point. Any suggestions other than try a new gasket?
Tom Fleming
Well-known Member
If the pistons and bores look good. And the valves look good. then yes, put on a new head gaskets and give her a whirl. If someone tried to reuse an old head gasket and thought that silicone seal would do the trick, that is your problem.
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