Centax clutch units can be tricky. My mrx6 wouldn't shim out. I had to remove the Mugen collet and install the Novarossi one that came in the box. Sometimes little things can make a big difference.

y would u want to use another clutch system the mugen clutch setup is perfect!!

What do you mean when started the engine to set the engage point of the clutch with the spring nut?? I should redo the clutch gap and the end play after some use yes? Keep the clutch gap to 0.6 - 0.7 and endplay from 0.1 - 0.2..

Thanks for the advice everyone appreciate it. I understand alot of it just need to nitty gritties and prefer to get accurate info and make sure i am on the track. Better safe that sorry!

When the gap and endplay is set you can adjust the engaging point of the clutch with the spring nut. tighter is later but also more chance of slip. Find a point the motor comes in a high enough rpm and locks the clutch.

You can stick a small pin (1.5mm hex tool from the kit) through the hole right behind the 20 tooth pinion and by rotating the flywheel feel it slide into a slot of the nut, then you can rotate the nut by moving the flywheel. Or you can remove the gearbox and clutch bell to reach the nut, as long you put it al together keeping the same shims you will not change a thing to the gap and endplay.

Yes, from time to time you have to check and correct the gap, but again there is no need to re-meassure it all than only the gap by removing only the endplay shims. When the gap did become 0.9mm just take away 0.2 from the endplay shims and add them to the gap shims.

Sorry for such a late reply guys. Ok i have set up the centax clutch and done exactly what was recommended. The end play i set to 0.6 and endplay is 0.1 - 0.2. Quick question so i know what to do, what do you mean set the engage point of the clutch with the spring nut??
Second question, how do you know when to move the shims from the end play to the clutch gap?? And roughly how long after should i move the shims? should the clutch stay the same 0.1 -0.2 over time?

Thanks for the help, sorry if the questions sound stupid but just trying to understand the hobby more.

I have a high rpm engine in it.. A nova .21 9 port ceramic bearings, long stroke. So you mentioned to find the point where the motor comes in a high enough rpm and locks the locks... Do i judge that when driving?? The aim would be to get the clutch to engage earliest?? or is that personal preference

The gap was set to 0.6 ?

Normally I push the car down on the worktable and give full throttle. If the clutch spring is set to loose the engine starts cogging on low rpm and low power, when it is set to tight the wheels do not spin and the car will not try to pull it self out of your hands (the clutch slips).
When set right the wheels starts to spin, the engine wants to do more and there is a high force that the car wants to pull itself out of your hands.

From time to time you have to check the gap. Just take the gearbox off and unscrew the screw holding the clutchbell. Keep the finger on the screw and remove the bell with everything on it. Remove the endplay shims and mount the clutchbell again, now you can measure the cap again.
Lets say it has become 0.9, just take a 0.2 shim from the endpay stack and put it on top with the gap shims. Then mount the rest of the endplay shims on their normal place and the whole clutchbell again. easy.

Ok cool, that makes good sense. Yea i have set the clutch gap to 0.6. taking shims off the end play to put them in the clutch gap, wouldn't that leave excess end play? I do catch engagement straight away or after a good run?

When moving a shim from 1 side to the other the total shimming will be the same and so also the endplay. You only shifted the clutchbell with that.

There is no need to warm up the clutch, only the engine a bit. Just start right away to find the right engage point.

This guy reminds me of myself when I started nitro racing lol. I very strongly recommend to watch Salvan's video. And Xray NT1 setup book can be downloaded from their website which helps set up the clutch and set up theory.

Awesome thanks guys really appreciate the help, I have it all ready to go just need a day off work and an area big enough to try it out. Actually have watched Salvans clip and i learnt alot from that clip just needed some in between help :)

Hey guys, took the mrx5 out today and didn't get it up to full throttle but close. I set the high speed needle. The clutch worked EXCELLENT, very happy with the centax now that i understand it. I have a question regarding tuning. The engine runs well and idols perfect, when running at quarter throttle and holding there, it sounds like it is leaning out, i richen the low speed up and it doesn't make a difference. The clutch engaged perfectly and the spring nut is in the right position. I am wondering if i can get some advice on tuning? I got it to the point where it sits and idols for 20 seconds and takes off without bogging down but then i drive holding it at a quarter throttle and it makes a kind of lean sound and I feel it is something to do with the low speed needle but can i get some reassurance on what needles are where??

Oh if anyone can put in the direction of some good temp guns as mine is to old and need new one??

Thanks :)

there really is no way to tell u where the needles should be I mean there are base starting points but that wont help, just watch the temp and that would be the temp for that motor different brands have different temps as to where they like to run. so check temp for high speed needle, low speed needle test put car on starter box let car idol for 5 secs and squeeze full throttle if it lean bogs like it studders then its too lean do it a few times if it don't lean bog your fine. also on the track go down straight full speed brake hard into the first turn and then full throttle if it don't lean bogg then again its fine!!

No worries, If the car is idling for around 10 seconds and when you go to take off its not moving until you rev it a bit, i know its to rich but is that on the high speed needle or low speed needle?

So i take it they are more built for moving up in rpm as apose to holding in one position?
Just to double check, the low speed needle is located on the moving end of the slide carb?

[QUOTE=Nitromad1020;15013010]No worries, If the car is idling for around 10 seconds and when you go to take off its not moving until you rev it a bit, i know its to rich but is that on the high speed needle or low speed needle?

So i take it they are more built for moving up in rpm as apose to holding in one position?
Just to double check, the low speed needle is located on the moving end of the slide carb?[/QUOTE

Coukd be both needles it's hard to say tuning is tricky, I never seen a car not move unless it's on break in so u just have to keep trying alittle at a time and yes low speed in on the throttle