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Old 05-27-2003, 03:10 PM   #1
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Default Nova Rossi engine Air leak or fuel leak?

OK.....I am recently experienced something that ppl might experienced before (but I never had one like this for the last 4 years)........I have a Nova Mega engine like RS-12......no matter how I tune the needle, it never works, no low-end and no high end.....and after I seat the car over night, I found their are oil dripping right below the front bearing area......(not from the carb)Just a reminder, the engine is only 2 weeks old, and I never unscrew any parts of the engine for cleaning except I had to loosen up the carb screw/nuts so I can rotate the carb 10 degree for my NTC3 (for all NTC3 race, you should know what I am saying).

I replaced the O-ring underneath the carb, cause I thought I broke that O-ring.....but after insert the new one, still the same result...........I think there are some AIR LEAK or FUEL LEAK (More likely AIR cause I don't see oil/fuel all over the engine)

my engine runs 150-180 range in temp, and no low-end and no high end at all........it is not opperatable.

Now........should I use those RTV (room temperature vilcanizing silcone) that my friend told me he used that on his real car to seal underneath the carb and the high speed needle nipple....? I don't really want to do that step if I am forgetting to check something........but if there are nothing I forgot or I have to check, I have to seal it and see what happend.......

Also.......what do you guys use to seal the carb...? I saw ppl on the track use something BLACK and said they can dry in 5 minutes...what is the name of those thing..? And where I can find them....?

Oh engine has full compression, cause it is new.

Thanks a million......
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Old 05-27-2003, 03:22 PM   #2
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RTV works well for sealing...


Do you have another carb that you could put into the engine? That would be what I would do, so I could get up and running quickly (also, I am a bit lazy ).

What ever is going on with your carbaretor is beyojnd me at the moment.
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Old 05-27-2003, 03:38 PM   #3
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sounds like you might have gotten an engine with a bad front bearing
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Old 05-27-2003, 04:32 PM   #4
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My front bearing use to leak too after the engine had been sitting over night. But after a couple weeks the problem seemed to dissapear.
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Old 05-27-2003, 06:56 PM   #5
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The front bearing leaking should not be a problem, it should stop after a few tanks. You need to give a little more information on the engine. Best bet is to go back to factory settings, and start over. Does the engine sound blubery, you may be running to rich. Your temp settings, is that F or C. Are those readings at idle.
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Old 05-27-2003, 07:26 PM   #6
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In my opinion, you have problem with a sitting place for the crank shaft. Regardless you opened or o, on the factory they might overbored, just a little bit and now you see result of it! I would check this first-check if your crank shaft is not too lose in the crank case (check without without bearngs). Got question-wright it !
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Old 05-27-2003, 09:43 PM   #7
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thanks for all the information.....and I will try them all one at a time....meanwhile, I just hope the engine oil leaking part will disappear like someone mentioned, but I will keep an eye on it.

The best way for me to investigate is WATCH the oil moment from the engine when the car is on the starter box.........and I hope I can spot the oil leaking area.........

However, i don't think I can spot the air leaking position......I can only seal the carb and hope the engine can runs fine.
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Old 05-27-2003, 09:53 PM   #8
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Quote:
Originally posted by Rookie Solara
thanks for all the information.....and I will try them all one at a time....meanwhile, I just hope the engine oil leaking part will disappear like someone mentioned, but I will keep an eye on it.

The best way for me to investigate is WATCH the oil moment from the engine when the car is on the starter box.........and I hope I can spot the oil leaking area.........

However, i don't think I can spot the air leaking position......I can only seal the carb and hope the engine can runs fine.
I know it is kind of tricki to check krank shaft, but I will strongly recomend it. i had couple times expirience like that-it was frostrating! i hope i'm wrong, but it might take place!
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Old 05-27-2003, 10:07 PM   #9
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I once had similar problem where the oil (after run) leak from the front bearing when the engine was new. I checked with my LHS, i told him i put in lots of after run in it, and this is the reason for it. Since then, no more leaking and i only put reasonable amount of after run.
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Old 01-16-2005, 01:05 PM   #10
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Quote:
Originally posted by RClover
I once had similar problem where the oil (after run) leak from the front bearing when the engine was new. I checked with my LHS, i told him i put in lots of after run in it, and this is the reason for it. Since then, no more leaking and i only put reasonable amount of after run.
What shop ?

I have after run oil leaking too It is dripping oils from front bearing. The engine is 2 weeks old
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Old 01-18-2005, 05:44 PM   #11
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This is a problem with some of the Novarossi engines lately. I have a motor I was ready to pitch into the "Round FILE" but I kept doing different things, tracking the problem. This is what I found. The seal on the front bearing. Take the motor apart and pull the crank out. Look at the front bearing fron the back of the motor case into the light. If you notice that the inside of the seal has a "ring" of light, you have a bad seal on the front bearing.
If this is the 7x17x5 bearing, it is a hard one to find and if you get another novarossi one, chances are it will go bad very quickly too.

If you would like to get one at a decent price and have 2 seals for the bearing, go to a bearing distrib, and order a mr697(this has the rubber seals) and if you would have noticed some of the more expensive motors, they are now coming with metal shields, this is part number mr697zz.

What I was experiencing is no matter what I did to my carb settings, I couldn't get the temp down and it had a "FLAT spot in the mid range, like it was loading up and then it would take off like a bat out of hell. Since I replaced the front bearing with a $12 part. the motor has been acting fine and it is accepting the adjustments with correct response.
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Old 01-19-2005, 05:23 PM   #12
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To check for an air leak, fire it up on the starter box & spray a fine mist of water at all the places it can leak. If the engine flames out suddenly when the water hits, there is your air leak. put some blue permatex where the leak is & your all good.
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Old 01-19-2005, 07:28 PM   #13
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Quote:
Originally posted by rcfoolz
If you would like to get one at a decent price and have 2 seals for the bearing, go to a bearing distrib, and order a mr697(this has the rubber seals) and if you would have noticed some of the more expensive motors, they are now coming with metal shields, this is part number mr697zz.
I'm told that the front bearing will leak a little somehow and that the reason for 1 side of the bearing not having seals is mainly for lubrication purposes of the front bearing. Wouldn't using 2 seals for the front bearing be dangerous when the bearing does not get enough lubrication?
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Old 01-19-2005, 08:13 PM   #14
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You may need to check your fuel lines.

Oil will naturally drip out of the front bearing when it sits for awhile. That happens in all engines. I run Nova Rossi engines in my r/c boats. The first thing we replace is the front bearing. You can check for air leaks in the engine by covering all holes and blowing on the crank. Sounds silly, but you'll hear it.


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Old 01-20-2005, 03:29 PM   #15
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initialD......you are suppose to remove one and save it for a later when you need one again. and I understand what you are saying that it will have some leakage, but the 7x17 bearings for some reason wear the seals out so bad that you can actualy hear the leak when it is fired up. Listen for the sucking sound and you will know, they are that bad
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