I am having problems w/ my '70 XLCH using oil and getting very hot. It doesn't smoke,knock,starts/runs good,plugs are dry. I took the rocker plugs out and there is oil up there. Why is it running so well if it is the valves or rings(no smoke) Any ideas

 

maybe youre temp guage is not working correctly.....???...just a thought... maybe a weak oil pump or return lines clogged?????

 

how hot? do you ride alot around town? where there is stop and go traffic? need to know how hot it is getting

 

The oil tank should get hot enough to burn your leg. The rocker covers should get way too hot to touch, and should take a lonnng time to cool down. With no oil cooler oil temp should be around 200`F. I would not be concerned unless it exceeded 220`F.

If you are concerned about valves and rings then do the static compression test and the cylinder leakge test. The gauges can be purchased at Princess Auto or Harbor Freight. Notes follow ...

Cylinder Compression And Leakage Tests

A compression test should be done as part of any tuneup. Record the results and follow any changes over time. A cylinder leakage test should be done any time you are considering taking down the top end. This test gives you useful information regarding what you should look for when you have it apart.

Each of these requires a tester which you can buy at any auto parts store. A compression tester could be found for about $40.00 more or less, and a clyinder leakage tester for somewhat more than that amount. With the cylinder leakage tester you will also need a small air compressor. Should be able to find a small sausage style for under $100.00.

Use these tools once and they have paid for themselves, compared to paying $50.00 to $100.00 per hour at a shop. Buy a slightly larger air compressor [look for about 5 CFM @ 90 PSI] and you will be able to use it with air tools.


Compression Test

1. Run the engine to get it up to operating temperature
2. Disconnect and remove both spark plugs
3. Screw the compression tester into the spark plug hole for either of the cylinders
4. Lock the throttle open, and ensure the choke plate is also open
5. Crank the engine through several rotations until there is no further increase in reading at the tester guage
6. Record the final reading
7. Repeat for the other cylinder

The difference between the two readings should not be more than 10 psi. A low reading on one cylinder indicates possible valve or ring dammage to that cylinder. To determine which, pour about 1/2 oz of oil into that cylinder through the spark plug hole and repeat the test. If the reading returns to normal then valves are good, rings may be defective. If compression does not return to normal then valves may require service.


Cylinder Leakage Test

This test will tell you what to look for at the teardown: worn exhaust valves, worn intake valves, leaky head gaskets, or worn rings.

This test is usually done immediately following a compression test. So the engine is at or close to normal operating temperature, and the spark plugs have been removed.

1. The piston must be positioned such that both the intake and exhaust valves are closed. To accomplish this, set the cylinder to be tested precisely at top dead center [TDC] of the compression stroke, as follows:

Rear wheel off the ground, shift to 2nd gear, rotate wheel until it clicks, repeat until you get to 4th gear. Now by rotating the rear wheel you are rotating the engine. Almost impossible with the plugs in; very difficult in lower gears. For the following it helps here to have either a shop assistant or a wide "wingspan".

Keep a thumb pressed on the spark plug hole while rotating the back wheel. On the compression stroke you will definitely feel the air pressure working against your thumb.

You can see in thru the spark plug hole, especially with a flash light. You can also try inserting something soft like a pencil and watch it rise and fall as you rotate the engine with the back wheel; but be careful it does not break or get stuck! You will have to hang on to the pencil with left hand while rotating the rear wheel with the right.

2. Turn on the compressor, connect the gauge to the air pressure, and adjust the gauge
3. Thread the adapter into the spark plug hole and into the gauge
4. The gauge now shows the amount of leakage
5. Listen at each exhaust pipe. Excessive hissing here indicates the respective exhaust valve is not sealing
6. Listen at the A/C intake. Excessive hissing here indicates intake valve[s] not sealing
7. Listen at the timing plug hole. Excessive hissing here indicates the rings are not sealing
8. Listen around the cylinder/head connection. Excessive hissing here indicates the respective head gasket is not sealing


Notes

The piston must be positioned so that both valves are closed

A mechanics stethoscope [with the probe removed for this test] makes a good listening device, as does a length of oil line hose.

Greater leakage results in a sound of lower pitch.

There will always be some leakage, especially past the rings.

There are many variables here [engine temperature, precise piston position, whatever] so the test results will not be consistent from one test to the next.

 

Let me start by saying that I have a 1970 XLCH that I have had since new. Two things that I had happen over the years that made mine get hotter were:
1. A very lean fuel mixture.
2. I put some 10-40 Valvoline racing oil in it ( for a very SHORT period), had to go home and change back to 50 wt.

 

Awesome!

 

You be using 70 wt oil. If you can't fine 70 wt oil then use 60 wt.. It's still going to be hot but your runing the right oil in it.. I book saids I should be using 105 wt in mine but harley doent made 105 wt oil. SO I use 70 wt.. Runs good. The weather here in Chicago has be in the Hi 80s and 90s. So 105 wt oil would work even better. Hope this helps you..
Tom

 

where are you finding 70-105 wt,80-90wt is gear oil,no way you could run that thick in an engine..every harley uses 50..

 

Sorry pal... 70 WT Kendell is GOOD stuff when you can find it and I have been putting 60 WT Valvoline in my '77 Ironhead ever since I first bought it back in '82 and after putting almost 35,000 miles on her, she still runs GREAT and doesn't leak a drop of oil (It didn't come stock with a chain oiler from the factory or an oil filter) and doesn't smoke or burn any oil in the exhaust. Try putting in the best oil that you can get into your motorcycle and keep it maintained and serviced when needed and it will reward you with many years and many miles of happiness and pleasure.

 

i think we went through this in here before and for the life of me i cannot remember all the important info but i beleive the mixup was due to different ratings......even though it seems absurd i beleive there are different thickness even though the rating is the same.-----------------for me i use castrol or valvoline (because its the best i can find in my area i beleive)20/50 in winter and 60w(harley davidson oil because thats what the bike shop carries) in summer.