jeff1

I'm running 20% nitro fuel and I didn't changed head clereance, any problem here?

M7H

You don't have to change the headcearance, with 20%.....

Advise for on track break-in.....

Lean the engine far enough so the car will move, don't burn your clutch, so maybe set it to early engagement....
On every 1/2 tank, lean the top end by 1/8 of a turn (I said 1/4, bus this is to fast) and i recon you will have the engine broken in within the next 4 tanks of fuel......
I myself would lean the engine faster, but would not recommend you to do that..... (but no need to go past these last 4 tanks, because it already swallowed 8 tanks, which should be enough for the total break-in process)
Also set the idle to the lowest possible rpm, without the engine shutting down immediately, but keep in mind that it will not idle for ever (some do, but this depends on more settings)

Keep the bottom end a bit on the rich side, so that when the car takes of from zero, the engine makes a small "gurgling" sound......

Enjoy, I have received some PM telling me that this engine is capable of lifting the front wheels of your car......

jeff1

Tomorrow I will finish this
Really? Lol, but sincerely, this engine rev much better than the old Evo2, and still on rich carburation. I can feel that

jeff1

I finished the break-in and one thing very strange happened. The big piece that control the air induction (sorry, don't know the name) started to drag on inner part of carb body. It happened one time after I fire up the engine. I felt it wrong when I applied throttle and the engine didn't answered. I have taken the carb out and tried to take this big part out, but was without sucess. When I put some WD40 I was able to take it out. I analized the part and found nothing, only a little bidding when I place it again on the carb body. I noticed that this part don't travel smooth as nova carb do.. it biding My question: what the hell is this? Have you ever see this?

Another question. The engine didn't run great with this LSN setting. I had to lean it a bit, now the needle is something like 1.3mm out of the big part that I said before, not of the ball link (flush with ball link). When I set 1~2mm out of the ball link after clean the engine the rpm droped after 2~3sec and the engine died, now it idles for more than 20s
The HSN is about 0.3mm out of the housing
The temp was about 70~90ºC and the performance very very good.. A lot of smoking coming out the corners
Is the engine running too lean?

Thanks so much
sorry for my poor english

jeff1

Do you use any of those carb restrictor?

M7H

I know what you mean, I've read here about people who had similar problems, but I did not have any of those problems with my engines..
Before you can take out the slide from the carb, you need to unscrew the idle screw, this is also the place where I think the slide might bind, please check.....
If your idle is set to high, (or was set to high, because of a overly rich bottom setting during break-in) you might have damaged the slide a bit, where the idle screw touches it.....
No, I don't think the engine is running to lean....
But this is exactly why usually I don't really talk about factory setting for an engine, because they can differ......

If the engine takes of nice with a gurgling sound, and the top end speed sounds clean, then it should be ok...

jeff1

Slide problem solved .. didn't changed nothing, only dropped some WD40 and now is free moving
Now I would like to ask
I'm using a RB inline pipe on it. It has a gray aspect. Don't know the Efra number because it is dirty and the kerosene didn't cleaned. A guy on the track told me it is a good idea to upgrade to Mega pipe because it match better and I can gain more power. It is that true? Should I upgrade?

Winner's Circle

iTrader: (2)

Jeff,

I found that on the .21 Mega engines that I got a lot more power out of the Mega pipe and header that comes with the Powerpack. I was running a Nova Rossi conical header and 9886 pipe and it did not perform nearly as well on the Mega ZX and DS11 as the Mega Powerpack header and pipe.

Speed_Racer

Just got a brand new Mega ZX15 and It has very slight pinch at TDC w/o the plug. I could spin the crank completly. Is this normal?

razzor

The Mega 2607 pipe set works well on the DSII , I had a problem with the engine not reving up well ,found tha problem to be 2 pinched Orings on the bottem end needle.This is on a new DSII thats been run in and run on the track for one club meet.
Id suggest guys check the needle assemblies for thid problem when they get there engine and note the amount of turns for the factory setting.
Also put a bit of rubber grease or silicone oil on teh orings to help keep them soft.

The 2607 has got great bottom end and a very strong top end , I could keep up with a JP FX12 on the top and could pull away out of corners with ease.
Sure I seem to have it tuned right so this might not be the case for anyone one else.
I am running .5mm clutch gap , .1mm end play 1.2mm tension on a black 1.8 spring.Black shoes with all the weights in my TM G4S.

M7H

Yes....
But can I ask you, why did you try to turn it through TDC?....

M7H

The 2607 pipe is not for .21 engines.....

But, I run the engine with either the 2033 pipe, or the older 2018 (discontinued) depending on the track layout.....

razzor

The 2607 is on my .12 Mega DSII.

quietstorm76

iTrader: (12)

I just finished my second gallon of fuel on this engine with the original rod and the engine is holding up very well. I ran this engine hard on yesterday and I was very impressed. Very easy to tune and holds it's settings. There was only one engine that was able pull on me and that was a Murnan plus 21. But only towards the end of the straight, but everywhere else on the track we were pretty much dead even. Just make sure you run the mega pipe. My $100 novarossi pipe sucks on this engine.

latemodel13

iTrader: (101)

I just got a zx21 and thought i'd share something with everyone. I started checking the engine and noticed the carb slide was sticking a little so i took the idle screw out and removed the barrel. I noticed a very small burr where the slot for the idle needle rests. I saw in an earlier post another fellow had issues with the slide. I just took my dremmel and touched it up a little and now it slides great.