Help with Novarossi Tune

[Bad Inferno]

Help ! I have been trying to fix a two speed as I thought the engine was dieing when it shifted, however I took the two speed clutch out ie force the thing to only run in first gear and it seems that my engine is dieing at full throttle.

Novarossi .12 pull start in a touring car. The car flames out at full throttle after about 4-5 seconds of running flat out. the car accelerates really well however after about 5 seconds running at full speed it dies.

fuel is 16%
The LSN is set just about flush and the HSN is 3 turns out. Now I thought it made sence that the engine was flooding at full throttle however when I lean the HSN it will "bog" down on acceleration and nearly die, even with the LSN set flush or even 1/2 turn out from flush. Leaning the HSN does not allow acceleration. The mid speed needle is set flush.

I assume that an engine should run at full throtle in first gear, it is running really fast before it dies.

This thing is driving me crazy as I can tune the LSN & HSN for great idle, acceleration and top speed and I can feel the difference in the settings as I adjust however cannot get the thing to run flat out for any longer than 4-5 seconds. I was thinking of setting my trim not to open the carbie all the way however only masks the real problem. I have also installed a new Rossi plug

 

[kwong2001]

I'll bet you're over-revving the engine in first gear and making the engine run too lean. When it was about to die at the high rpm, how much smoke was coming out?

Also, were you adjusting the HSN first, then the LSN?

It'll probably help to get a higher nitro content fuel. 16% seems awefully low for a novarossi. Maybe try a quart of 20%?

 

[Bad Inferno]

The engine was running at 200-210 degrees and I could see smoke although did not seem excessive. I did not realise you can overrev an engine ?

I am adjusting the HSN first. Although as I have really fast acceleration and good top speed I am using the HSN setting more for acceleration than a top speed adjustment. I found if I lean HSN, as soon as I accelerate it "rumbles" and die's, thus my LSN is a long way out.

Maybe I should look into the gear ratio's and count the teeth. I do have some 20% nitro I run in my hyper 21 buggy would this be OK for a little .12 ?

Have you had any experience with a V-one Kyosho. I got this car second hand and someone has fitted a V-on RR two speed with rossi engine.

 

[kwong2001]

If you're locking out 2nd gear and maxing out the car pretty quick, you're gonna wanna tune for the top end. If you want acceleration, you need to bring back 2nd gear...yes you can overrev an engine.

Since you gotta bring your LSN way out, I still say you're running too lean. Reset the needles to factory and start over.

As for 20% nitro, you got a novarossi, it'll take 20% fuel. Although i'm willing to bet your engine is actually meant for 30%.

Oh, and seeing that you got the car/engine used, if all else fails, you may want to take apart the engine and check to make sure the piston/sleeve is still tight.

 

[Bad Inferno]

As I could not hear the second gear come in I did not think the two speed was working. I had a look at the gearing and have 16/20 49/45.

I have had trouble finding the engine settings and have scanned lots of forums with the same comment from others Novarossi do not publish settings with engine and the web site the generally gets reffered to is not working www.parisracing.com

 

[kwong2001]

Okay, this'll probably really rich, but set the HSN to 4.5 turns, LSN and MSN flush. It'll probably be extremely rich, but it's a start.

 

[Bad Inferno]

Kwong, Thanks for your help....however I will have to suspend tuning until my new spur gears arrive from hongkong. (rcmart)

I looked in the rossi manual that I have and you are correct I am using the lowest nitro recommended 16 (16- 25%). I ended up ordering a new 1st/2nd spur gears and clutch for 2nd gear. I already have a new oneway bearing so that means everything in my two speed is new and should work. When I looked at the two speed clutch it was not in good condition looks like someone has filed it. My last run I ended up striping the first gear so the car is in pieces again.

 

[Bad Inferno]

Can you always tell when your two speed changes ? I have a 45 and 49 tooth spur.

 

[kwong2001]

If it's set properly, you can usually tell by just hearing it shift. If don't hear it shift, accelerate a little slow and listen carefully for it to shift. It may just be shifting way early.

If you can't hear it shift at all, then loosen up the springs and again accelerate slow and make sure it's actually shifting

 

[Bad Inferno]

Thanks...its easy when you know whats happening.

I had the spring set too hard. The 2 speed clutch screws had been set at 3 turns out (from tight) however they needed another full turn. I am still runnning 16% nitro, when this is finnished I will stepup to 20% same as my buggy...easier to buy one fuel anyhow.