Rubbermount_EVO compression test question

[deguireb]

Hi,

I have a 2005 1200R, my compression is low according to the FSM and want to make sure I did it correctly. (Both are about 165psi)

Manual states "With choke and carburator throttle plates in wide open position" - I pulled the enricher all the way out, is this all that needs to be done when cranking the engine?

Thanks, Bryan

[sportsterdoc]

Air flow is needed for a compression test, so
a. hold throttle open to open butterfly
b. fully lift up on vacuum operated slide on CV40 carb

Opening enrichener only adds fuel, so leave closed.

[sportsterdoc]

Also, insure that spark plugs are grounded to avoid coil / ICM issues.

[XL1275]

Why are you checking compression to begin with?

[IXL2Relax]

Here's the Sportsterpedia section on Compression testing:
http://sportsterpedia.com/doku.php/t...:evo:engmech03

Having a compression test result from each cylinder is one of the most effective ways of monitoring cams, lifters, rockers, valves & piston rings from the outside. Readings should be taken whenever acquiring a new/used bike and immediately after rebuild and again after break-in.

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For FREE Sportster Tech Info from the XLForum:
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[deguireb]

Great, I'll try it again.

I started to get oil dripping out of my air cleaner. My breathers are stock and go into my air filter. Oil tank is not overfilled, keep it at 1/2 on the dipstick. Bike runs fine but something has changed in the last couple of months to cause this. Could be a few things, rings, valve seat, umbrella valve, …… . I want to fix and not just put a breather bypass on, even though I may still do that in the future.

[doc martin]

Originally Posted by sportsterdoc

Also, insure that spark plugs are grounded to avoid coil / ICM issues.

I dont understand how to ground the spark plugs

[wedge]

Originally Posted by doc martin

I dont understand how to ground the spark plugs

When you pull the plugs they are no longer touching the heads. You can use clip cords to clip on the strap of the plug and attach the other end to any good solid ground like the head bolts for instance.

I just pull both plugs out and set them on the bench, let the wires dangle and it has never caused an issue but Jerry is giving you the correct procedure.

Regarding why you are checking compression, that's good info for trouble shooting if there is an issue. Otherwise, I always do a compression check every time the plugs come out and I replace the plugs at 5,000 miles

ALWAYS write down the readings (dated with mileage) for future reference. You should keep a log of everything you do to the bike with every entry dated including mileage. It always comes in handy to know when you last did things and what readings you had.

For instance I just replaced my Harley battery after two years in one bike. Now I am questioning my habit of moving my tender to whichever bike I am not riding on any given day. It's not supposed to cook a battery but is it going bad? Was it just a bad battery? I need more data, but this is how you build a data table.

[deguireb]

Thanks for the advice, my compression is fine 200 in the front 205 in the rear. Guess I'll try replacing the umbrella valves. What else could cause more oil to exit the breathers to see a change after 58,000 miles?

[kitabel]

CCP tests are affected by engine & air temperature, oil viscosity (the 1st or low temperature thickness) and cranking speed.
I had a learning experience with an air-cooled engine decades ago, accidentally put straight 30 weight in it even though the air temperature was about 20° F. Turn the key: nothing, would not turn even once, therefore CCP = 0.

CCP numbers don't show oil control condition, just compression seal.