I recently ran in a new MR Ninja .12 that I purchased some 18 months ago. I am having heaps of trouble tuning this engine. I haven't been able to find the basic factory settings - nothing on the CD. The idle seems to stay high and then drop down, I have played around with both LSN & HSN and can't seem to get a good tune that holds.
The engine also appears to lack bottom end grunt compared to say my OS Speed Spec II. I am using the Ninja pipe that came in the engine kit.
Anyone out there had one of these and how did you find the tuning and overall performance of the engine.
I am contemplating having the engine worked up to improve it's performance.. is this worth it?

Bro, i when to check my needle setting for u.

- idm t6 plug
- 0.3mm shim
- 16% sidewinder fuel
- HSN 3 1/8 turn from close position
- LSN 3 1/2 turn from close position
- skyline pipe

This setting is what im using now... so far so gd... if u are using the ninja pipe, u can try lean a bit more. as i find ninja pipe run cooler then skyline pipe.

yape... u are right that this engine lack of bottom end, therefore inorder to improve it, you must tighten the clutch spring, to let it engage at a higher rpm. And this is a high rev engine... so change ur gear ratio to a higher one to bring out the power. DO REMEMBER to change the con-rod after break in, as ninja have a very tight p/s. Therefore the con-rod gone through high stress during break in. by changing rod can prevent serious damage and is worth to do that!

i personally find that this is a gd engine, very smooth running (when using ninja pipe) although i also very happy with mine using skyline pipe.

cheers!

The engine has bottom end, believe it. Just set the clutch properly and you will have no problem getting out of corners quickly. It also likes to rev, once you get the tune right.

Try richening the bottom and turning up the idle a bit, and you may need to lean the top a hair. I can't speak on using other plugs, but I've never had any problems running the ninja 5 or swap to a 6 if it's really hot or humid

Hi, we need to know what Nitro you use before help.

i have the same motor set up your talking about. i have the ninja pipe on the motor also. my motor did the same thing sounded like it had an air leak or something. after break in of about 12 tanks of fuel getting closer and closer to a race tune. i changed the con rod, output bearing and sealed up the motor with a light coat of o2 sensor safe rtv seal. carb,back plate,fuel needle inlet, everything my problem went away. like it was stated before the pinch is hella tight on the ninja motor, you should change it to be safe to get the total performance out of the motor. that motor tuned well can run up to "270-290" no problem. normaly i like to do a motor tear down after a break in anyways.

Thanks, Guys

I'll give it another go. I was thinking that it may have developed an air leak. I ran the engine in a qualifier at the Aust Nat's and from memory it was performing better but last club day it was a real dog. I have a new rod so I'll swap it out to be on the safe side as suggested.

Cheers,