Yamaha R6 Forum: YZF-R6 Forums banner
1 - 20 of 32 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter · #1 ·
any body have any insight to why my engine case is becoming pressurized to the point that oil is blowing out some of the seals?
the only thing i can think of is a blown head gasket or messed up rings.
doesn't seem to be burning oil and there is no coolant in the oil either.

2003 r6
 

Attachments

·
www.1seven1.com
Joined
·
2,063 Posts
any body have any insight to why my engine case is becoming pressurized to the point that oil is blowing out some of the seals?
the only thing i can think of is a blown head gasket or messed up rings.
doesn't seem to be burning oil and there is no coolant in the oil either.

2003 r6
Are your breathers plugged?
 

·
let her scream
Joined
·
71 Posts
check for plugged breathers or too much crank case oil.....i bought my bike and they topped it off....800cc's too much oil to be exact. after some high rpm riding i soon found multiple blown seals, oil pump, and left side case cover, i think i replaced clutch cover gasket to be safe
 

·
Official Noob Greeter
Joined
·
55,856 Posts

·
Ya wheelies is garbage!
Joined
·
5,935 Posts
Your breather is not fine. Absolutely no way you can pressurize the crank case with a free flowing crankcase breather. Anything and everything fllows the path of least resistance and that would be through the breather. Either somehow the hose it kinked or became blocked off. A blown headgasket wouldn't pressurize the case, it would pressurize the coolant system via the water jackets. Even if your piston rings were shot and pressurizing the the crankcase it would be relieved by the breather. A big hole at the top of your motor just isn't going to stop releasing pressure if their isn't anything obstructing it. If the oil filler cap is popping off when you go to remove it you obviously have something obstructing that free flowing path to the airbox. Might start inspecting your air box and the breather hose.
 

·
Banned
Joined
·
7,347 Posts
I agree with raven. no way it's letting air out/in if you have pressure.

kind of makes me wonder if someone did the breather hose mod (but did it wrong)where you hook the hose up to the AIS system but it's blowing air into the crankcase instead of sucking it out.
 

·
Ya wheelies is garbage!
Joined
·
5,935 Posts
I agree with raven. no way it's letting air out/in if you have pressure.

kind of makes me wonder if someone did the breather hose mod (but did it wrong)where you hook the hose up to the AIS system but it's blowing air into the crankcase instead of sucking it out.
Very well could be, if they removed those reed valves that act like one way check valves. Then it will be both sucking air out as it should but also blowing it back in since the valves were removed and no longer allowing unidirectional air flow.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #14 ·
problem solved...i re checked the breather hose. i checked it before and it was clear so i put it back on and figured that wasn't it. i took the hose off and ran the bike and it ran perfect. the hose has been disconnected from what ever it is supose to be plugged in to...i think some kind of sensor. they were put into a T and the other two hoses go back in underneath the air box. it always ran fine for the few years i have had the bike set up this way. could something under the air box be messed up? hoses are clear and there is a small amount of suction. will it hurt to run the bike with the hose disconnected? if it is ok i plan to put a small air filter on the vent and intake.
 

·
Banned
Joined
·
7,347 Posts
problem solved...i re checked the breather hose. i checked it before and it was clear so i put it back on and figured that wasn't it. i took the hose off and ran the bike and it ran perfect. the hose has been disconnected from what ever it is supose to be plugged in to...i think some kind of sensor. they were put into a T and the other two hoses go back in underneath the air box. it always ran fine for the few years i have had the bike set up this way. could something under the air box be messed up? hoses are clear and there is a small amount of suction. will it hurt to run the bike with the hose disconnected? if it is ok i plan to put a small air filter on the vent and intake.
that sounds like what I was talking about. if it is those are the Air Injection System hoses.
 

·
Ya wheelies is garbage!
Joined
·
5,935 Posts
problem solved...i re checked the breather hose. i checked it before and it was clear so i put it back on and figured that wasn't it. i took the hose off and ran the bike and it ran perfect. the hose has been disconnected from what ever it is supose to be plugged in to...i think some kind of sensor. they were put into a T and the other two hoses go back in underneath the air box. it always ran fine for the few years i have had the bike set up this way. could something under the air box be messed up? hoses are clear and there is a small amount of suction. will it hurt to run the bike with the hose disconnected? if it is ok i plan to put a small air filter on the vent and intake.
Sounds like someone just didn't do the kleen air mod correctly. Alright take a look at this picture and completely disregard the hose labeled 3(there should be two hoses, one on each side that feeds back to the front of the airbox). #4 used to tbe the crankcase breather that would normally run to the port on the back of the airbox. Hoses #1 and #2 were the hoses that went to the AIS solenoid originally. If your bike is set up like the picture below and the case is being pressurized the reed valves were removed. The reed valves are under the plates that connect to hoses #1 and #2. They allow the exhaust to suck air, but don't allow it to blow any back in. So if the reed valves are in place as they should and hoses #1 and #2 are T-ed into hose #4 for crankcase breather the exhuast will eleviate any built up pressure by sucking air through the reed valves and out the exhaust. However if those valves are removed air can be sucked out but will also be able to blow back in when the engines load decreases allowing the crankcase to pressurize.
 

·
Ya wheelies is garbage!
Joined
·
5,935 Posts
hmm. my reeds are out, mod is done, but ive never had leaks or crank pressure problems.
Uh uh. A2k said Dave cutler told him to take them out so I did. Then my bike started seeping from the valve cover and a few other spots and would pressurize the case. A2k said he's ran fine like that too, but mine sure didn't like it. IDK maybe theres another aspect but as soon as I put mine back in like OMR told me to everything was gravy and you could feel air sucking through the filler cap instead of blowing when giving it throttle. IDK man you're the pro.
 

·
Ya wheelies is garbage!
Joined
·
5,935 Posts
lol. i would like to cap them off and try just venting at the crankcase nozzle, but i would like to see some photos of how others have done it, without puking oil out through the vent while riding, ya know?
I wonder if you coudl just take a long piece of tubing and run it up to the upper stay and have a breather filter on it. Then that would be straight up and down while the bike is at 12 or on the bar... IDK maybe that would work
 
1 - 20 of 32 Posts
Top