Nova P5T .21 tuning problems

[asar]

I have a brand new .21 Novarossi P5T engine installed in a new buggy. After the break-in and was starting to lean the engine's Hi end needle the engine dies at mid throtle to WOT. I leaned my high end but my temp now is as high as 275-285 F and would still die from time to time most especially when I'm at mid-throtle for a while and pressing for WOT. My idling is ok, Low-end seems ok - leans out after 3-5 sec of pinching.

This is my third Novarossi engine. The first was a .12 and a big frustration in tuning after the mid range needle was touched. My second was a .12 RST5S1 and seems to be ok, no problem. This third Nova .21 engine is giving me the same problems as the first.

I don't want to mess around with the mid-range needle, but it seems my mid range is bad. Just overhauled my carb but same problem persist. I hope it's not a factory defect air leak problem.

 

[FlyinRazorback]

Sounds as if your HSN is too lean. Probably wouldn't hurt to richen the bottom up a bit also. I would set it to idle for about 5 seconds before it starts to cut off when pinching the fuel tubing, not any sooner. Also, you want to run a cold plug (McCoy 9 or RB/NR 8). This engine runs best at temps from 205 - 225. I wouldn't suggest leaning it out any farther.

If you are really upset with it, send it to me and I'll send you a freshly broken in RB S7 plus $50

 

[asar]

P5T tuning

Thaks for your advice. However, if I richen the HSN the engine dies off quicker. I have not finished a whole tank of nitro (Monster 20%) without the engine die off. Usually it starts to stall from 1/2 tank onwards.

I will try a colder plug. I am using RB #6.

Originally posted by FlyinRazorback
Sounds as if your HSN is too lean. Probably wouldn't hurt to richen the bottom up a bit also. I would set it to idle for about 5 seconds before it starts to cut off when pinching the fuel tubing, not any sooner. Also, you want to run a cold plug (McCoy 9 or RB/NR 8). This engine runs best at temps from 205 - 225. I wouldn't suggest leaning it out any farther.

If you are really upset with it, send it to me and I'll send you a freshly broken in RB S7 plus $50

 

[FlyinRazorback]

What are your needle settings? BTW, do not mess with the mid-range.

 

[slothy]

ummm didnt think p5's came with a midrange needle ? just low and high ? i know mine doesn't..

are all your fuel/pressure lines in good shape (no pin holes ect ?)

i had a prob with my front bearing leaking and causing a tuning issue - 10-15 tanks into using it

 

[asar]

P5T tuning

The Novarossi P5 T (turbo) is a new .21 engine release. It has 3 needles. Tried doing many adjustments...lean, rich both on HSN and LEN. Didn't touch the Mid range though. I wonder if anyone with a P5 has same problems tuning. Engine is kinda hot 270 - 285 F to run without stalling. Dies off when rich

 

[Nitroaddict]

u may be so lean that even richening it a bit isnt solving the problem. Most Nova based BB engines run pretty cool - about 220-240. What you describe sounds exactly like the HSN is far too lean. I would richen that HSN a full turn and see what happens after a tank for the settings to take effect. Also - what % nitro are u running?

 

[slothy]

Re: P5T tuning

Originally posted by asar
The (turbo) is a new .21 engine release. It has 3 needles. Tried doing many adjustments...lean, rich both on HSN and LEN. Didn't touch the Mid range though. I wonder if anyone with a P5 has same problems tuning. Engine is kinda hot 270 - 285 F to run without stalling. Dies off when rich

i thought the turbo was just the button head insert...

can you post a pic of the carb, I'm curious now

 

[dgrobe2112]

First thing i would do.. is get a new plug.. and see if thats the problem..

if the new plug dont fix the problem.. you got a tuning issue.. get a new plug and fatten both the top and bottom end needles..

Set the low end first.. by starting the car.. rev it a little to clear it out.. with pliers.. pinch the fuel line around 1-1 1/2" from the fuel nipple.. it should idle round 4-5 seconds before you hear a change in note to the motor.. thats where you want it to be.. if it tried to die before that.. you want to fatten the low end needle.. counterclockwise by 1/4 turn.. if it takes along time.. then you could be too fat on the bottom end..

Once you got this set.. you can then leave the low end needle alone.. you dont tune the motor using the low end needle.. reason is

The low end needle is only used for around the first 1/3 of throttle.. after that.. the low end needle dont come into play.. and dont affect the overall performance of the motor and does not affect the high end performance of the motor.. however.. the high end needle can affect your low end performance..

With that said.. you want to get the car on a good straight path.. and run a couple high speed runs.. a good starting point for the high end needle.. and this is a general starting point.. is 3, to 3.5 turns out from fully closed.. this will be fat probably.. but its better to be fat.. and tune from there.. than to be lean and tune from there..

Run the motor a couple passes to get the motor up to temp.. if the motor seems sluggish and slow.. with a gurgling sound.. then you are too fat.. lean the needle by 1 hour.. which is 1/12 of a turn.. like this.. just an example.. if your needle is facing like this

| lean it to where it looks like this / and thats it..

run another pass or 2.. temp the motor.. you will want to run between 220-240.. not sure on the P5, some say it runs really good at lower temps.. so if you can get the motor running in the 220 range.. and have lots of power.. you should be set..

 

[FlyinRazorback]

Another thing, you may want to get rid of the turbo plugs / button. Now that I think about it, I had a Sirio that did the same thing about a year ago. Would flame out about 1/2 tank. Run hot. I sold it but some people changed to the standard button and it remedied the unexpected flame-outs. Just a thought.