front engine bearing
12-27-2009, 08:40 PM
#1
front engine bearing
I was breaking down my engine (jxBo1A), it has a little less then 2 gallons.
Anyway, when i took the back plate off then put it back on, when i did it made a hissing sound in the front bearing. I know some leakage is going to happen on front bearings, but how much? When i turn the crank it was smooth. When i turned the bearing with my finger i could feel some resistance in the balls. I want to say it felt gritty, but i don't think so.
Also, when i took the button head off and the piston out, there was alot of deposits on the piston head. I could also push the piston right below the ring mark. I know it's an O.S. so it loses metal pinch after a gallon.
For you seasoned racers, how much of this is normal?
byrons 30% btw. Does this sound like a normal rate of wear?
i have more P/S and do not need it yet, but it's looking like 4 or 5 gallons on that P/S.
man, electric is starting to look good.
Anyway, when i took the back plate off then put it back on, when i did it made a hissing sound in the front bearing. I know some leakage is going to happen on front bearings, but how much? When i turn the crank it was smooth. When i turned the bearing with my finger i could feel some resistance in the balls. I want to say it felt gritty, but i don't think so.
Also, when i took the button head off and the piston out, there was alot of deposits on the piston head. I could also push the piston right below the ring mark. I know it's an O.S. so it loses metal pinch after a gallon.
For you seasoned racers, how much of this is normal?
byrons 30% btw. Does this sound like a normal rate of wear?
i have more P/S and do not need it yet, but it's looking like 4 or 5 gallons on that P/S.
man, electric is starting to look good.
12-27-2009, 08:48 PM
#2
That hissing sound was just the air inside your engine being exerted displacing the volume of the backplate. As long as your not having tuning problems, and you don't have a puddle of oil under your engine, don't worry about the front bearing. However, you said you thought it felt gritty. I would definitely check that out. Also discoloration on the piston is normal http://www.rctech.net/forum/nitro-of...ston-head.html
12-27-2009, 08:52 PM
#3
That hissing sound was just the air inside your engine being exerted displacing the volume of the backplate. As long as your not having tuning problems, and you don't have a puddle of oil under your engine, don't worry about the front bearing. However, you said you thought it felt gritty. I would definitely check that out. Also discoloration on the piston is normal, do a search and you'll find a few threads on that.
I knew the backplate was pushing the air out. Just never really paid attention to it i guess. Would a leaky bearing cause it to run cold?
12-27-2009, 09:08 PM
#5
i have leaned it out all i can and it reads 160 on the side 140 on the head and 220 at the manifold. Runs and sounds great, lean it anymore and my engine will fry. I have it now 2 1/4 out on the HSN and 3 turns out on the LSN (or a full turn and a half in from flush). Idle gap is hair thin. Midrange at the factory setting.
Has a trail of smoke and thats about it. No big puffs of smoke, the engine doens't really load up either.
when i got a good tune i richened it a couple hours to be on the safe side, but when i do the temps drop to almost 130. Like i said, that is the temp on the head. If i take it on the back of the engine by the manifold it's over 200.
but this doesn't make sense because i have taken temps of the head at 200.
p3 plug btw. It's been about 60 degrees outside.
12-27-2009, 09:10 PM
#6
Am i using to much ARO?
I also preheat my engine.
I also preheat my engine.
12-27-2009, 09:12 PM
#7
ninja, 2 gallons.
i have leaned it out all i can and it reads 160 on the side and 220 at the manifold. Runs and sounds great, lean it anymore and my engine will fry. I have it now 2 1/4 out on the HSN and 3 turns out on the LSN (or a full turn and a half in from flush). Idle gap is hair thin. Midrange at the factory setting.
Has a trail of smoke and thats about it. No big puffs of smoke, the engine doens't really load up either.
when i got a good tune i richened it a couple hours to be on the safe side, but when i do the temps drop to almost 130. Like i said, that is the temp on the head. If i take it on the back of the engine by the manifold it's over 200.
but this doesn't make sense because i have taken temps of the head at 200.
p3 plug btw. It's been about 60 degrees outside.
i have leaned it out all i can and it reads 160 on the side and 220 at the manifold. Runs and sounds great, lean it anymore and my engine will fry. I have it now 2 1/4 out on the HSN and 3 turns out on the LSN (or a full turn and a half in from flush). Idle gap is hair thin. Midrange at the factory setting.
Has a trail of smoke and thats about it. No big puffs of smoke, the engine doens't really load up either.
when i got a good tune i richened it a couple hours to be on the safe side, but when i do the temps drop to almost 130. Like i said, that is the temp on the head. If i take it on the back of the engine by the manifold it's over 200.
but this doesn't make sense because i have taken temps of the head at 200.
p3 plug btw. It's been about 60 degrees outside.
are you taking the temp at the glow plug? not the side or manifold, ON TOP of the head where you put the gp in?
if so and you have a consistent trail of smoke, no lean bog then dont worry about temps.
12-27-2009, 09:16 PM
#9
i have the silver one that came with it, and one copper shim. The copper shim is as thin as they get. I am running 30% so i have to have 1 right? some people put 2 shims with 30%.
12-27-2009, 09:20 PM
#10
I'm not familiar with those engines, so maybe someone else can chime in and tell you what shim to use. Here's some info about where i'm coming from . .
http://www.rctech.net/forum/nitro-of...cool-head.html
http://www.rctech.net/forum/nitro-of...cool-head.html
12-27-2009, 09:30 PM
#12
would to much after run oil make it run colder? I so put a bit much i think.
12-27-2009, 09:54 PM
#14
plugs already dry. Guess i could richen the top a couple hours then the top will be at almost break in settings.
I will lean the bottom a couple more hours. ttyl.
I will lean the bottom a couple more hours. ttyl.
12-27-2009, 09:56 PM
#15
we dont really know where he is getting his temps though because he takes them all over the engine.
the only temp you need is right on the glowplug witch should be right around 190-230
if its around 50 degrees it will be cooler on the engine as it has cooler air running over it.
if its 100 degrees the engine is going to read in the 220-240 range
the ninja motor can run all day long at those temps...
dont tune to temp btw if its making some good smoke all around and running fine and making all the jumps on the track with out much effort then leave it alone.
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