GREGORY!

iTrader: (1)

Any help guys?

mjthompson

Hi, i have the 2006 version of this engine, i understand it has had the carb update.

I use 16% tornado fuel, with No.6 std plug and the silver (0.1mm?) head shim removed.

I have been having trouble with my engine since new, and its had 5 litres of fuel ran through it.

I think i may have an air leak in the carb somewhere. When i'm on the track and back off for corners or pit stop the engine revs rise, and it sometimes screams. but if i let it try to idel it dies after 2-3 seconds, so i have to keep reving it.

Please could someone advise what is best to do. Shall i change all of the o-rings in the carb? Do you get all of them in the o-ring set (ORI81325)?

does this include the ring that seals the carb to the crank case?

i have the needles at factory settings with the man needle leaned slightly to run good on the straights.

please help.

Matt


PS. Nano, thanks for all of your help in the thread. Great job. And i know these engine are great from what the people are running in the nationals, i just cant wait to get mine running like that.

AddictedToRacin

Sounds too lean on the bottom end.
You have to be very careful beacuse sometimes the engine seems to be to rich and is too lean. Try to open the needle one turn and fine-tune it from this point.

mjthompson

thanks, so it doesn't sound like an air leak then?

i wasn't thinking it was too lean. (im probably wrong), because it seems to take along time to clear its self and when it does it spurts out smokes a lot.

so is the factroy setting usaully too lean on the bottom?

thanks people.




Matt

rmdhawaii

iTrader: (4)

When your engine revs like that when it's off throttle, this works really well:
http://www.rctech.net/forum/showthre...91#post3185991

mjthompson

Thanks everyone, ill give that a go.

am i wrong in thinking that if you set the low spped needle first, that you will inevitably (sp?) change it when you adjust the high speed needle?

I'm using my engine in a Serpent 720, with 2647 pipe with high torge manifold and an orion clutch conversion for the serpent centax 3.

Does anyone have a good clutch set-up for this version? what gearing do you use in the 720?

Cheers


Matt

Osiris 75

iTrader: (18)

Have they made a Wasp clutch set for the X-ray NT1?

Nano

Mj, if your clutch setting is right, you should barely have to touch the low speed setting from the factory setting. Our basic principle is that if you have to go way off the factory carb settings then something is wrong. Usually the engine only requires a little leaning on the high speed needle and almost nothing on the low speed. If the engine is used/maintained properly you usually don't get air leaks from the carburator.

No special clutch set for the NT1 yet.

rmdhawaii

iTrader: (4)

Does this mean Team Orion is going to make one for the NT1 or is the yellow NT1 shoe good enough for now? How does it compare to the CRF shoe?

B4

iTrader: (1)

Make sure you are not compensating for a bottom end that is to rich by having the idle speed set to high. Remember make small adjustments only.

rmdhawaii

iTrader: (4)

This is an interesting idea. I wonder how well it works...

CRF 88925 Manifold Spacer (1mm/2mm/3mm)
Enables length of exhaust to be adjusted in 1mm increments, without changing the manifold or muffler.

mjthompson

Nano, thanks for the response. (and everyone else)

i have the idle the lowest i can go without it dying, but it still revs crazily when i back off.

i have set it on the bench so it maintains a steady idle but am yet to try it on the track, i think it will be too rich on the bottom.

does my clutch need to be tighened, or take one screw out each fly weight?

do i measure preload by measuing how much thread is revealed above the spring tensioner?

does 2mm preload sound too much on the centax III? or is 0.5 clutch gap too small?

Am i right in removing the silver head shim? should i take out the copper one and put the silver one back in? I'm in the United Kindom.

Thanks

pitbits

Hi Matt

It sounds to me that your bottom end is too lean. A couple of us who run this engine at Nationals had this problem. The solution is to richen up the bottom end. However you must remember that the engine has to be fully warmed up before bothering with tuning it. I've found that It needs a good couple of minutes on the track (sometimes longer) before it's properly warmed up. My engine wont tick over until it's up to temparature, so setting the idle when it's cold will give you an engine that revs too high when it's warm. Once it's warm it will idle fine.

I'm happy to help you tune it at Wrexham on Saturday if you like.

mjthompson

thanks pitbits

Nano

There's always a lot of testing going on with clutch systems at CRF. However it takes a lot of testing and experience with a particular clutch to make something that works properly. For the moment nothing is planned for the NT1.