Crank O Ring oil seal

Robbins Racing

Robbins Racing

Member
Had a problem out at the track today. The O ring around the crank backed its way out almost flush with the case. This caused oil to leak and get into my sons outboard clutch causing it to slip during the heats. Anyone seen that before? I was able to seat it back in almost 1/4 in. I didn't find the where the leak was until I got it home and in the garage, fellow racer lent us a motor for the main. Best community EVER!!
 
Yes
Make sure you don't have any obstructions in the crankcase ventilation system.
That means the hose that comes out of the valve cover, the catch can, the catch can vent and even the valve cover itself.
If the ventilation system prevents crankcase pressure from getting out it can build up and blow out the seal.
If you don't find anything just pick out the old seal, install a new seal and move on.
 
Something has to be causing it to blow out though Jimbo...id be betting on a bad valve cover baffle...change the valve cover just in case if you have a spare
 
Really? That much crank case pressure in an LO206? Wow. Those seals are pressed in, I would have thought that the sidecover gasket (if it has one) would have blown out, or the breather line would have blown out before the oil seal pushed out.

I would be guessing that it simply wasn't pushed in deep enough at the factory (or that the lip on it folded under during installation - easy mistake.)
Glad you got to borrow an engine to keep you going though.
There is a chamfer (more pronounced on some sidecovers than others) that you need to get that seal below. Sounds like you got it deep enough now -- also make sure that it is completely square (equal depth all the way around.)
Soak the clutch in acetone to get rid of the oil and you'll be good to go again. (Be sure to re-lube the bearings.)


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Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
28 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
Brian
I'm just saying that it is possible.
Why leave any stone unturned?
In fact if you have too much restriction and the crankcase can't breathe the fuel pump won't work.
I also agree that the reason it blew out is that either it just wasn't pressed in all the way or MORE likely reason is that STUFF JUST HAPPENS.
 
I loaned a LO206 to a friend that usually raced a WF. The 206 rules require a catch tank for the valve cover tube ( WF's do not) so he rigged one up using a thrash can plastic bottle. Halfway into the first heat he is sitting off of the track with ' a slipping clutch". Sure enough his "catch can" was not vented and the oil seal was blown out. It very easily can happen.
 
I had my oil breather tube melt and seal. It caused the gasket on the engine side cover fitting for the pulse tube to start blowing oil out. I thought it was the crank seal at first, but found it was the gasket for the breather. Brian, I didn't think a 206 would have that problem either until I had oil all over the side of the engine. Old dogs new tricks I guess!
 
So the first season I had to tune for my son solo I left a rag on the axle, sent him out for practice and the rag got sucked up by the chain and bound up behind the inboard clutch (Rookie mistake I know, son came off the track saying he though he hit a bird LOL) . That shredded the O ring and it was replaced by my local shop so it wasn't the factory seal. Clutch was inboard at that time so we didn't have any performance issues as oil didn't make it into the clutch. Seal looks fine but I will be replacing it myself for peace of mind.
 
You can clean the hole with acetone and some Qtips then a light coat of adhesive sealant or red rtv. Don't run it until it cures. Dress any burrs on the shaft before you push the seal on and a tiny bit of oil on the seal will help it on the first start.
 
sundog said:
You can clean the hole with acetone and some Qtips then a light coat of adhesive sealant or red rtv. Don't run it until it cures. Dress any burrs on the shaft before you push the seal on and a tiny bit of oil on the seal will help it on the first start.
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If running LO206 rules or IKF, your not allowed to put sealant on either the PTO or Flywheel side crank seals.
 
If it ain't broke don't fix it!
Why go looking for trouble?
There are enough things that can go wrong.
It seems like I've heard this a million times.
Ever since you (fill in the blank) my (fill in the blank) doesn't work right.
 
flattop1 said:
My question is if it's not leaking what advantage would changing it give.
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None. And it probably won't unless some chunk of dirt or other object makes its way in there which is very unlikely. However, the likelihood of damaging it while installing it is 10x (estimate not a scientifically derived statistic) more likely to result in leakage.
 
sundog said:
He said it wasn't oem seal so not legal.
Click to expand...

I guess when I read "his local shop" I assumed they used the brings crank seal. Not sure if I have ever seen a non-OEM one, but okay. I will also say dried silicone seal or gasket maker would like result in "crud" breaking apart and ultimately ruining the seal, so legal or not, I would not recommend it.
 
Hi all,

I am new to karting, just finished my first race this past weekend. I noticed oil splatters on my chassis below the clutch and a fellow racer mentioned this could be the crank seal. By the end of the final, my clutch was slipping. This leads me to believe I have a leak at the crank o-ring seal and oil got into the clutch.

I will check the ventilation system, but I will need to either push the seal back in or replace it. Should just press the old one in with a socket? Should I replace it? What is the procedure for replacement? Can I just pick the old seal out and press in a new one with a socket?
 
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