Sounds like your needles are out of balance. Bring your hsn back to flush and retune your bottom end. Lean bogs are caused by the hsn. Remember your hsn is more of a "overall" needle anx needs to be a little fat when tuneing the idle.

Yeah I know, but at 3.5 or flush motor is way rich on the top and has no rpm on the track. To get it close to race tune it has to be a little in from flush. I am stumped. I have had multiple people tune on it and they are stumped too. I know it defies the laws of Nova tuning.... I have a CRE P5 cranked down to about 4 - 4.25 on the LSN and it runs fine with the HSN in from flush also and great temps.....

It is puzzling so I just run it where it is at. I still get 9 minute run times, but I should be 10+ with this motor.

what fuel ? plug ? pipe ? .......... did you test the front bearing with brake cleaner ?

Nova 9886, 30/9 Byron's, Werks #6. I did test the front bearing and when you spray it, idle rpm has absolutely no change at all!!!! So I am guessing it is not front bearing......

N21R Limited 3 Port anyone know who has one of these cheap motors in?

also are these the same motors


Novarossi N21BF-LIMITED
SKU: N21BF-LIMITED


Novorossi N21RLimited
SKU: N.21RLimited

My 21-4BTT came in on Saturday. It was like a light switch. Temps dropped 25 degrees, instant drop to idle and pulling harder then ever on top now. Awesome!!!!

ok, on the pressure line, it was a suggestion by a engine modder, has worked really good for me during break-in. i stop after i get about 1.5 gal through engine

I know the BTT doesn't care for the 9886 too much..........Werks #6 may be a tad cool for a stock BTT tho.....

Thanks Neal, I will try a Werks #5 and mess around with a few pipes I have. Going to the track tomorrow and see if I can get it a little better balanced.

so your engine passed the brake cleaner test using Byrons ?

Yes it did no problem. Which leads me back to the tune has to be off. If I set it at 3.5t on the HSN it runs pretty good it is just lacking a little on the top end. However it still lean bogs a little on the bottom. If I richen it up a little more on the HSN, it fixes the bottom so I can run it at 4.5t out, but the top is rich and not very crisp and snappy you expect from a Nova. I am going out tomorrow night and try to get it balanced again a little better making really small increment changes to it at a time.....

The motor screams, does not flame when refueling at about 3 HSN, 5.25 on the LSN, feels really smooth and snappy, I just can only run for 9 min. which I guess I shouldn't complain about, but with my other Nova's I run 10+ easy. On your CRE P5 I am literally at 4 on the LSN I believe, and about 3 on the HSN. Big difference, but not exactly apple to oranges though.

A guy runs Plus-4 also here and he is 4.25 on the LSN, and right at flush on the HSN and I can not get anywhere near that with almost all things being the same......

I just need to play with it tomorrow night I will get it dialed in.....

Hey,

I actually just picked up an n21r limited. It's actually a nice little motor, has more than enough scoot for buggy. It's a very smooth motor, tunes well, though I don't like the old style carb as much as the new one. Run times aren't great maybe 8:30 or so (not bad I guess). Running a 2096 pipe, has great low-mid range. Geared it up 1 tooth and has a great top too now.

All in all a great backup or small track motor, might try the Nova 9886 or ofna 086 pipe for a little more top end.

Where sir?

I run Coldfusion Majic blend 30/10

Novarossi reccommends
25% nitro
6% castor
4% synthetic(total of 10%)
65% methanol

i know the Coldfusion is not a dry fuel like Nitrotane and some of the others, there is always a really nice film on all the internal parts after i'm done with a tank and i never have any rust or any need for afterrun oil either for that matter

Im About to start running in my Toro Nero, is one of the below method's a good choice, or can someone recommend an other.

I normally pre heat and put a tank through it on the box. Drop it on the floor and run it around doing figure of 8's for the 1st 5 tanks keeping the heat in the engine. The next 5 tanks are up and down a car park but no more than 3/4 throttle. Between tanks i let cool down with the piston at BDC.

Or try this one...

Thanks

Ross

Mount engine in car , preheat engine using competition heat engine warmer (easiest most prefered method) , prime engine by blowing into the pressure line and holding carburetor open until fuel has reached all the way into the crank case .

Preheat to a temp of at least 170° fahrenheit , start engine , you might have to keep it idled up a lil at first until engine settles into a smooth idle (hotter plug helps with break in). Monitor temps frequently , if temps start climbing higher unplug comp heat unit , use low speed needle and idle screw adjustment to get engine to idle between 190°-210° . Let idle for 5 min then shut down , leave head covered while idling , repeat this process three times , preheat , idle , shut off , cool down with piston out of the pinch area or BDC .

Next step is similar , preheat , start engine , idle for a minute or so , make sure carb is fairly close to "in balance" but hsn fairly rich lsn 2-3 hrs rich of a race tune and run car on the ground for approx. 10 min. , you will have to tune engine so it stays at 190°-210° while running the car around in a parking lot with the body on (do not over rev, use 40'-50' lengths so as not to gain too many rpm's) , no head cover . Repeat this process 3 times - preheat , run car on ground for 10 min., shut off , cool down with piston at bdc .

Next step is same as on ground intervals but this time do 30 min intervals on the ground with the body on no head cover . You can start to drive car on track for this but do not over lean engine , do not over rev!!!!!! , keep temps between 190-210F and do not "blip" the throttle , all these steps are important .