:lol:

Tell em' Homicidal Bunny thats rite!!

Taking advantage of my unusual wabbit tendencies :P

Excellent! wibbidy wibbidy wibbidy wabbit!
Maybe this phsycho wabbit can tell why the #%@#$ I have all this black black residue/oil? chalked onto a part of my head cumbustion chamber and piston! Looks liek I was running SUPER DUPER rich but I really havent been. Id say on the slight rich side ive been running on avg. but before that very rich for a long break in lets say pretty rich for almost a gallon. Do I now clean this crap off and run a new plug? Ive never seen black build up like this on an engine like this. Its kinda chalky and rubs off but its hard to rub off like its very lightly stained chalky residue. The mill is ready to be beaten on now and I need new plugs and a race tune now but hope this crap doesnt keep building up. I did run some break in fuel.

If it's black like that, sounds more like you're running super-duper lean. I had a guy at my track who blew up a repinched Mugen Ninja JX2 because he overheated from a really lean tune, and the internals had the same black, chalky substance on the head of the piston.

Oh damn, well the plug is still in tact. The coil is a light grey, the tip of the wire is grey but the base of the tip of the wire is black if you can see what im saying. The flat part at the very end of the coil, just before it starts to coil down. That part is black, but the tip is grey, the part that molds to the butt of the plug (LOLOL) How can i be super lean if my temps never get above 210?!?!!! This nitro thing is killin me rite now lol I know its not hard, but everything ive been seeing now is contradicting information and theories ive learned.

I do the spit test too and avg. a time of 3-4 seconds sometimes longer to burn away. I dont get this. 90% of the time i see smoke from the pipe, sometimes a lot and sometimes a thin trail. I do the pinch test and avg about 4.5 seconds to quit

So if i ran a little lean for some tanks at this point lets say, whats the worst that will happen? Id need a new piston, sleeve and head button?

Try change fuel, some fuel tend to built up the residue, run odonnel fully synthetic then it will be very clean but i doubted the lubricant package, just my personal opinion

It's hard, I still don't know a whole lot. But, the most common mistake that the more experienced guys see with someone's tune is that they're way too lean on the top end, and way too rich on the bottom end. It's possible that that is why your temps are in an acceptable range. 4-5 seconds to die seems a little bit rich (It should be about 2-3). How easy is it to rub off the black matter? Does it seem like a similar compound to what you find on the body of your pipe (burnt oil buildup)? If it is easy to remove, it's probably a false alarm.

If anything you would need a new piston, sleeve and conrod set (not a new head button). BUT, running a little too lean for a couple of tanks SHOULDN'T do much damage, but just periodically check your compression. If you can easily turn the engine over when it's cold - even if you only have to use a tiny bit of force could be a bad sign. You can also try the "3:15 test". This is where you take your engine out of your car, take the pipe and manifold off too. Then, turn the flywheel anti-clockwise until you reach TDC, and then let the cooling head fall to your right (which will try to turn the flywheel/crankshaft anti-clockwise). If your engine turns over after any less than 10 seconds, you are running very low on compression, and you will not have the same performance you once did.

Imo is more tuning issues, carb out of balance

Definitely.

:nod:I think you guys are right. The real problem is I just dont have enough time for consistent use in this hobby right now. After work Im always fighting daylight and cramming enough time in to get to destination, heat the engine get everything situated, drive the engien a bit and saturate the engine, then start tuning. By the time its running pretty good I dont have enough daylight to test it for optimal tune!! UUUGHGHGH lol

Im pretty close now, today ill just go by the tuning bible, the first 3 steps under the tuning section. Its basically wat i do but this wat should be a little quicker. I'll make sure the pinch test is dialed in for about 6 seconds to die, make sure the idle is good and steady then start tuning. I tried 40% the other day with this drag mod and it was fast but not optimized with tune and shims im sure. It ran too strong and I didnt like how high the rpms got, not really necessary for an everyday basher like me

Next week a few new parts comin in that I think will help the tune even more
New line, new high quality bell/bearings and a new 2058 pipe :nod:
I gotta say tho, I am loving the massive and smooth bottom end the 2013 gives :)

Just take it easy... Play safe... Good luck

Brand new Novarossi BTT-WC engine. The port in the slave doesn`t match accurate with the case.
Huge manufacturing tolerances?

I've seen a lot of internals like that. Most of the time, manufacturers will machine out a case that will fill several models. Thus the reason some of the ports in the case don't match exactly with the sleeves. Not a big deal IMO. The sleeve is what is metering your port flow, timing, transfer ect.... That is more important the making the case match the sleeve on every model. If NV did this, they would have to have like 50 different cases for each model they sell. and that's just their .21 line.

I know there are a lot more Motor Guru's on here that will chime in.

thats normal on any engine

Shudnt be a problem as long s p/s fit in

I have never seen such a huge tolerances in any engine i used before.
And the btt is the most expensive engine i have.

Here a pic from my RB Blast V4. Very nice fit. My p5XLT looks similar the RB.

Not a problem in any way , shape or form , run it

Is the Plus 4-BTT still a good option for a buggy?

Longevity question about nitros

When my Nova Keep Off 7 engine is cold with everything installed on it its still very hard to turn over all the way through a cycle. How much fuel will it take to kill away all that compression if ran at reasonble tunes and always at BDC after runs and always pre heated?

....oh ya and broken in correctly and not rushing a lean tune

Many factors like quality of fuel n air filter... Keep a good maintenance then it will last

Excellent option still.

There will be all sorts of opinions with header/pipe, but I don't think you can go wrong with the 9901/41021 combo.

Does anyone have more info on the new Novarossi 41031 manifold?

http://www.amain.com/Novarossi-41031...nifold/p360742

I've driven it on several different engines. It made all of them noticeably more powerful compared to the 41021. It drinks more fuel though.

I have two P5 's on my Workbench taking apart. one crankpin measures 4.9 mm the other 4.8 My question is 4.8 to much worn. only 2 gallons on both.

Frank... Those engines are toast. Give them to me. I will take off your hands:lol:

For real though, 4.8 is not that bad. I measured mine brand spankin new Clio ( newer version of the P5) and it was at 4.95, So I think you should be fine.

If it still running right then good to go unless it wont. If only 2 gallon then during break in period, not enuff heat generated to run the motor. It stress the conrod n the pin...

Whats up fellow Novarossi fanatics :) Does anyone have a factory setting for the idle screw? How many turns out or in for a good start point. Thank you

Depending on how accurately it is being measured. If it is truly 4.8 that is worn .006" or more and is way too much. I am assuming you are using a caliper, a micrometer is more accurate. With the crank worn that bad the rod will also have wear and you could have .010" total slop which will not last long. I consider .003" total slop or worse a back up engine.

Rex

4.8 is very bad.
You are right that at new they are 4.95, I get the same measurement on mine.
However, my engines when worn to the point that they have so little compression that they don't run right, generally tend to measure around 4.88-4.91.

Now this is where it gets interesting, engines that have been re-pinched and then ran a whole lot, end up measuring at 4.82-4.86.

My friend recently had his con rod come out through the crank case on an engine that had been re-pinched and ran at least 5-6 gallons after that.
The last time I measured the crank pin it was 4.81-82 and I warned him that this could cause a catastrophic failure. Sure enough, boom, rod through the crankcase.

So no, 4.8 isn't fine, 4.88 might be fine for a while, but 4.82 definately is not fine.

Thanks for the info. How much less was your run time per tank?

Im glad to see someone say why someone else is wrong. To many times on line, you get that "you are wrong" and that's it. ;)

Keying into what I was and wasn't saying, not "that bad" but yes bad none the less. Problem is when you measure something that small and precise and leave such a big open ended number ( 4.8mm) when it should have at least 2 or 3 numbers after the decimal. And Frank didn't really specify where he should have.

question about your buddys motor? Did the rod break or did the crank pin sheer? I really don't see a worn crank pin could snap a rod and shove it thru the case. But that's just me. Harmonics? Vibrations?

If Im wrong, enlighten me some more. Im a knowledge whore!:lol:

Due to the cost, imo wen it stil running right, y change it. We all know Novarossi parts are costly.

I'm getting about 30 seconds less per tank in truggy.

.

The Efra 2032 (not approved anymore) with a Novarossi 41001 header is a living beast with better mileage than 9901/41001.
My pinched, rebuild BTT out-ran any other engine at a race this summer... and it was fitted with a 6mm mizer venturi. Very impressed :D