I have a 93 evo motor and there is oil coming out of the breather pipe.It has been doing this for a while but today noticed that I had been spraying specks of oil on a mates bike that was following me.The motor doesnt seem to be burning oil but Im thinking that maybe my rings need replacing because maybe the cases are presurised and pushing oil out. Im going to test the compression does anyone know what it should read.And do you think its the rings?
Is it spitting out heaps when you first start it?, the check ball in the pump may need cleaning, do it any way, if the ball is not seating, oil from the tank drains down when the engine is off and then gets blown out the vent, your scavenger gears may not be as efficient as the pump side causing a bit of wet sumping. Its a common problem with shovels. also if you have one of those gay chrome filters on the end of the breather hose, throw it in the bin, they clog up and cause all types of issues.
Thanks everyone I know I dont have those mushroom valves in my rocker boxes and there arnt any head breather gear I can see .This motor has been made up of bits from a number of years.Thanks for the article , I will take apart the oil pump and make sure it is working right and put some breathers in the head and see how I go.
Thanks for all your replys this is for me what makes this website so good because someone on it will know how to sort bike problems that the manual or asking a bike shop cant.
If its a bitsa you might want to check your breather gear is timed correctly ie the timing marks on your cam, pinion and breather gear line up and the housing for the breather gear is not scored, if its scored i heard the new S&S reed valve fixs it up.
G'day evoshovel,
Good advice all around.
I can vouch for the S&S reed breather, my evo's breather cavity was scored and I fitted one. Works briliantly.
Head breathers as Dave said started in 93, however some 92 models had unconnected breather tops and still used crankcase breathing. Another example of Harley clearing out old stock.
Houli suggested the check ball as an area of interest. If you get to the point of checking/disassembling the oil pump because the check ball is not seating properly, you can use an old pushrod and some fine valve grinding paste to re finish the seat.
Cheers,
Cris.
Today I fitted the chrome banjo fittings that are connected buy a steel pipe , all that was in the head before was a couple of 1/2 inch cap screws so it wouldnt be able to breath through the head.The oil pump is the next step and then new back sproket and chain and front one. It seems a bit never ending at the moment.I will look into the timed breather set up , I will have to have a bit of a read up on it.
