Well, my bike is. Puking oil, that is.

I’ve got a 1999 Dyna Super Glide that I got from my brother in law a few years ago. He bought it new, and had 10.5:1 pistons installed, along with a set of SE204 cams, and a Thunderslide kit on the CV carb. I replaced the Python exhaust with a Super Trapp about 15K miles ago. The bike now has 64K miles.

About a year ago, the bike started blowing a bit of oil, especially when ridden hard. Nothing serious, it was more of an annoyance than anything. Last month, when I was switching out the CV for a Mikuni HSR42, I decided to replace the head breathers while I was at it. I had some breathers left over from a Cometic gasket kit from when I did a big bore kit on my Road Glide.

Oh man, it made it worse! Much worse. I couldn’t ride the bike at over 3000rpm for more than a mile without it puking oil all over the side of the bike. Lots of oil. I thought, maybe those breathers were wrong, being from a gasket kit for a 2007. So I got the genuine H-D breathers, P/N 17025-03A.

No difference. I still had a gusher. The bike is unrideable. I replaced the air cleaner, thinking if it’s clogged, it could be sucking oil into the intake. Nope, that wasn’t it. I externally vented the breather system. Nope, it just puked oil out the hose. Each time I tested rode the bike and it started blowing oil, I would ride it home, short shifting at about 2500rpm, and the puking stopped.

Okay, now I get serious. I disassembled the cam chest to get to the oil pump, thinking there’s something gone wrong on the scavenger side. I’m telling you, the oil pump looks beautiful. No scoring whatsoever. The cam tensioners show a little wear (replaced at 40K), but are intact. No evidence of sumping, but that may be because I babied the bike riding it home on the test rides. Plugs are dry, look great in fact. Nothing is giving me a hint as to why I’m blowing so much oil.

I’m stumped. Can anybody give me a clue as to where to look now?

Thanks,
Dave

 

Too much oil in the crankcase. Take out about a cup of it to start with and if that doesn't alleviate your problem take out a little more until the dipstick reads about half a quart low.

 

Cold, the oil level is right at the add mark. This never changed from when I replaced the breather valves.

 

Have you done a compression test? The rings may be worn.

Oil keeps your engine cool. Removing oil from an air cooled motor is just asking for problems.

 

No, I didn't run a compression test. Can't now that I've disassembled the cam chest. I did pull the plugs, and they had absolutely no signs of oiling. Nice, light tan coloring. For what it's worth, I've also had no smoke out the exhaust.

 

Have you drained the case to see how much oil is in there?

Sumpin' is goin' on, and you have to systematically find it.
Have seen oil levels in tank look normal, but case was full of oil also so it had way too much.
Hi rpm longer riding blew it out as it has to go somewhere.
As said, rings, but you are not seeing any smoke out the pipe.
I always run a quart low, but I also run a specific breathing system for my twin cam to control oil pressure at extended hi rpm runs.

Next would be pull rocker box covers and check everything upstairs.

 

what about the engine seal behind the compensator ? does the primary have the correct amount of oil in it ? oil rings in cam plate in correct locations ?

 

There didn't seem to be excessive oil in the cam chest, but I didn't pull the plug on the crankcase itself. I'll do that when I get home from work. I think I've read that no more than 5 oz. should drain from the crankcase. Does that sound right?

I'll give the primary a look. Are you saying it could be sucking oil out of the primary and causing sumping?

I'm not sure what you mean by the oil rings in the cam plate. I hadn't had the cam chest open at all until after this problem surfaced.

Thanks,
Dave

 

sorry to say ...but this is bad piston rings ...the combustion pressure is blowing by the rings and pressurizing the crank case too much , pushing oil up the pushrod tubes to exit out the breather bolts ...they are design to only exit the air being pushed up by the downward motion of the pistons...

 

Yeah, or close to it.
You will know instantly when you pull the plug, as case sumping will gush out and be obvious.