Leaking air on the Flywheel area

[judexromo]

Newbie here, be kind

Used the bubble test to check leaks and found air leaking near the flywheel. Removed the flywheel and air leaks on the bearing(part#5223). Is this normal? If not, should I replace that bearing? It is easy to replace? Thanks.

[chadkillzone]

I would pick up a new ones, it can throw off your tune. As far as replacing it its pretty easy I just striped down to your block and place the block in the oven at 200 degrees and they pop out usually. Just be sure to have gloves on is all and you can clean and inspect everything while your at in there.

[judexromo]

Thanks, I did the leak test because the engine is having an issue with idling.

[Wildman4910]

If it is not leaking fuel then you are probably fine. Even new bearings will "leak" air as they do not have a true seal on them.

Fuel puddled on the chassis or a line of fuel slung around the inside of the body means a bearing in that is leaking.

Retune it if your having an idle issue, tune @ half tank, engine warmed up, HSN, then LSN, & then HSN if needed making a WOT pass between each change. 8 out 10 times tuning is the issue.

[Double G]

If it is not leaking fuel then you are probably fine. Even new bearings will "leak" air as they do not have a true seal on them.

Fuel puddled on the chassis or a line of fuel slung around the inside of the body means a bearing in that is leaking.

Retune it if your having an idle issue, tune @ half tank, engine warmed up, HSN, then LSN, & then HSN if needed making a WOT pass between each change. 8 out 10 times tuning is the issue.

Agreed. Everyone is so quick to point to a mechanical issue than a tuning issue; typically the front bearing is to blame. You can get as little or as many bubbles as you want depending on how hard you blow into the engine. Again, if you do not have fuel being slung around the chassis and body then the front bearing is not the problem.

[Nitronaught]

+2 I see people jump on the "Leak" bandwagon too quickly....

There is not a bearing made that has a perfect seal. Best way to tell a front bearing is leaking is take your lid off and see if fuel has been slung around from the flywheel. If there's no fuel residue on the back of the flywheel or slung around the inside from the flywheel then it's not leaking enough to be a problem.


So,,, how about a few more details as to what the O.P is experiencing.
What symptoms are you experiencing?
How old is this engine, how many gallons have been used?
Fresh Glowplug? if so what plug are you using?
What are your running temps?

[Redsawacs]

Nitro,
Before we move on, can I get clarification? I have fuel being slung around the chassis but for the most part, I am not experiencing any tune issues. Should I tear down and replace the bearing? Is the cause of this "rich mixture"?

Press "1" for yes
Press "2" for no


"Red"

[lubecakes]

LOL nitro.....What brand of fuel and how much use on the engine?
No tune issue, no problem I say. They will sling fuel if you're running too rich or have too much oil in your nitro fuel.....which is probably the case here. Front bearings don't go bad nearly as much as inside bearings, and you'd hear a distinct buzzing sound if the inside was shot.

[Nitronaught]

Nitro,
Before we move on, can I get clarification? I have fuel being slung around the chassis but for the most part, I am not experiencing any tune issues. Should I tear down and replace the bearing? Is the cause of this "rich mixture"?

Press "1" for yes
Press "2" for no


"Red"

You are having to run richer at the carb because your are losing fuel from the bearing..... Sure it will run like that, but it is going to get worse... I'd say replace the bearing, and if you have 4 gallons, might as well check your conrod by putting a drop of 3 in 1 houshold oil onto the area where the crank connects to the conrod, turn the flywheel back and forth. IF the oil squeezes out, your conrod is not doing so well. It usually is fine, but you've got the engine apart why not?

LOL nitro.....What brand of fuel and how much use on the engine?
No tune issue, no problem I say. They will sling fuel if you're running too rich or have too much oil in your nitro fuel.....which is probably the case here. Front bearings don't go bad nearly as much as inside bearings, and you'd hear a distinct buzzing sound if the inside was shot.

I guess you missed the part where he said he was having to richen up his needles, he's having to compensate for the loss of fuel on the front bearing.....
Runnig too rich causes fuel to be slung from the front bearing? I don't think so... If it was THAT rich the conrod would be swimming in fuel and at high RPM's the conrod would fail.... Also you wouldn't be getting up to operating temps over 200 degrees if there was that much fuel... Heck I doubt the engine could even run if it was rich enough to start pushing fuel from a good front bearing... I don't think it's possible.

[lubecakes]

Oops, I thought red was the op. Is the OP gone? Anywho, Where does it say 4 gallons? Judging by Jude's other posts it's clearly running rich. Too much fuel means poor atomization, which will cause fuel to seep out of the front bearing.

[Nitronaught]

Oops, I thought red was the op. Is the OP gone? Anywho, Where does it say 4 gallons? Judging by Jude's other posts it's clearly running rich. Too much fuel means poor atomization, which will cause fuel to seep out of the front bearing.

The owners manual says you should check the conrod after 4 gallons as part of regular maintenance I believe... It is a good idea since he already has to remove the backplate anyways if he's pulling the crank and replacing the front bearing....

All front bearings leak a little,,, it's when it's to the point you have puddling, or the flywheel is slinging the fuel around that it is affecting tune and performance.....

But a good front bearing there really is no way it is going to leak that much if it is too rich... You won't be able to keep it running long enough or it's going to run so bad, even worse, you would not get up to operating temps..... Then your problem is going to be lack of expansion of the block/sleeve and stressing the internals to the point of failure.....

I don't know where you are getting this from but I think you are describing a front bearing that is not quite leaking enough to be replaced, but not quite holding it's own either... You can run with a leaky bearing, but it will get progressively worse....