1980 Sportster Tappet Guide Problems : V-Twin Forum: Harley Davidson Forums

HDSINCE73 · 04-15-2009, 08:32 PM

Whats Up Guys New To The Forum,hope You Guys Can Give Me Some Insight.i Have A 1980 Ironhead Sporty.the Bike Runs Great But I Have A Leak Thats Driving Me Crazy.on The Front Cylinder The Intake Valve Tappet Guide Is Leaking Where It Gos Into The Case.and I Have Tried Nearly Everything To Fix This.new Tappet Guide New O Rings,tried Gooping It And Nothing Works,and The And The Old Tappet Guide I Removed And The New One Fit Very Snug It Feels Like A Great Seal.but I Tried To Fix It Again And Once Again When I Started Her Up,it Started Bubbling Air Out And Then Leaking The Oil Out Again.i Was Talking To An Old Gearhead And He Said There Should Be No Pressure Coming Out,but It Appears I Have Some.the Breather Tube Is Not Plugged Up And Appears To Be Working Fine.and Like I Said I Cant Even Get The Best Silicone To Hold It.any Info You Guys Could Provide Would Be Appreciated.man I Am At The End Of My Rope Thanx

the tick · 06-20-2009, 05:48 PM

can you feel air at the breather when bike is runing ?
you check to see if the case was flat or cracked ?
have you tryed hylomar?

Hillside · 06-21-2009, 06:35 PM

What is the OD of the tappet guide, and the ID of the bore where the guide goes in. Need to measure with micrometer/bore guage.
Scott

06roadglide · 06-21-2009, 10:15 PM

Your old gearhead friend is correct. There is no oil pressure at the guide, the tappets get lubed by gravity down from the rocker boxes.

You must have case damage or a breather problem.

brscott73 · 08-13-2009, 07:11 PM

I had a similar problem, and racked my brain when every 500 miles, oil started to spit out of the tappet covers. What I found to be *MY* problem was that the push rod covers are slightly less/more than a right angle with the gear case. This means that the spacing around the bottom of the push rod cover is inconsistent. When the motorcycle runs, the push rod cover 'settles' into place by sliding slightly up into the engine head. This causes the uneven gap between the push rod cover and gear case to widen which allows the tappet cover seal to slip in at the widest point.

My remedy was to use two o-rings at the TOP of each push rod cover, keeping the cover from 'settling' and the tappet seal from slipping into the widest gap. I now have ~2500 miles with no leak on the tappet cover. Just a bad design for the push rod covers. I know Harley-Davidson mechanics who hate the design due to this issue.

This may not be your issue, but it is worth consideration.

-Br-