BACK PRESSURE

nobbyjohn

Active Member
I talked with John Sachs awhile back about my engine blowing oil out the carb he said that if i took out one of the plugs in the crankcase that would help alot . i,am susposed to vent it thru a one way valve has anybody tried this yet and where did you get the one way valve.plesae anybody????
 

francoblay1

The Spaniard
I am not sure how he did it (Andrew Barnes) but when he was at my place he did something on one of the vents coming out of the heads....

You might want to give him a call to have a second opinion? just a thought.

:cheers:
 

BadDawg Bill

Well-Known Member
I would say you have a blockage somewhere in the oil lines/motor or bad rings/valves. You could relieve some pressure but it won't fix the main problem.

I once had a motor with a blocked oil return and it puked oil out of every hole it could find. Good luck.
 

john sachs

Well-Known Member
S&S one way valve part # 50-8122.
White toward the head, black toward a/cleaner or street, rear head vent.
If the oiling doesn't stop, then remove a rear crankcase plug, install hose barb, hose, another one way valve, white toward case, black to street. Guaranteed to solve your problem after disconnecting vacuum from the front head.
John
 

BadDawg Bill

Well-Known Member
How would i check for a blocked return line
Take the oil fill cap off and with the bike running see if oil is swishing around real good. If not then take each line off the oil tank and blow it out to see if it's crimped or blocked.

Did you ever clean your oil screen? It's the screw looking thing on the right block rear right next to the cam cover and next to the oil sending unit. Take it off and pull up the rod and screen and clean it good.

Have you changed oil filter types or have an oil cooler? The back pressure is caused by something not right so I'd check it out. What john is telling you will make the bike breath easier but something isn't right. Good luck.
 
Last edited:

SKOGDOG

One of the old ones.
Here is a source for the check valve. .375 nylon S&S part #50-8122: about $6.14+ $10 shipping.
M&M Cycles | 4416 Tiffin Avenue | Sandusky, Ohio 44870 | 419-624-8739
sales@mandmcycles.com
You can also have your local shop order it.
 
Last edited:
This can happen if your oil level is too high. It should be an inch below the bottom of the fill tube.


Sent from my iPhone using Tapatalk
 

superduty

Member
Once again this forum helps, thanks john for answering, it helps everyone reading. I was cleaning my dog when I noticed my carb had a drop of oil dripping out. All said my cb filter was in backward, go figure.
 
Top