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Old 09-16-2009, 05:17 PM   #1
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Default this should test all you engine experts.

Here it is. My ninja runs fine. but it runs cold, like really cold. After 3 tanks, i can reach down and pick my buggy up by the cooling head with no problem. runs anywhere between 138 and 180. Mostly around 155. New temp gun. I have the HSN set at 2 1/8 and my low speed and 3 3/4 out and my mid leaned 2 hours. and from what i understand this is still a too lean setting for most people. I am running 20% oddonell with just the silver shim and not the copper one. I have no idea how to explain this. Or maybe i am in the twilight zone


so can someone explain?? Or have a idea on why? remember now, it runs constant and has no leaks. New bearings and sealed. well the idle is low, and will stall out if i leave it too long. But that is not unusual

so is this a annomoly? a one of a kind engine? It runs great and rips. I mean i can run it and run it and run it. Leaner, richer doesnt matter.


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Old 09-16-2009, 05:21 PM   #2
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3-3/4 on the low seems way out there to me, my engines wouldnt start that far out. but what i would do if i were you is keep turning them in a little at a time. how much run time you getting?
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Old 09-16-2009, 05:23 PM   #3
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I don't know but I do know if you run a engine too cold it is worst than running a little hot, the parts don't get up to a normal temp and it puts more wear on them.
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Old 09-16-2009, 05:23 PM   #4
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if it runs as good as you say trow the temp gun away,go to the track,and have fun and quit worring about it
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Old 09-16-2009, 05:25 PM   #5
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do you notice any oil coming out of the exhaust?
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Old 09-16-2009, 05:25 PM   #6
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If it runs good like you said & milage is comparable to others at your track then I would say your temp gun is off or you measure differently than others. Sounds cold to me but I only use temp guns if motor is running really strong all the sudden & to double check my brain from the stand so random pit guys can work with the way I like my motors.

If its one of those lazer pistol grip guages the lazer should not be pointed at the plug or you'll be checking temp at the top of the head not the plug wich is the most common place to check.
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Old 09-16-2009, 05:26 PM   #7
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If it tuns good then just run it.
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Old 09-16-2009, 05:32 PM   #8
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If your air filter is restrictive/very dirty/ very oily....it can effect the air to fuel ratio and thereby cause it to run rich in a situation where exact tunings on a different engine with a clean filter would run leaner. The same is true if your exhaust is restrictive.
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Old 09-16-2009, 05:32 PM   #9
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Would the plug have anything to do with it runing that low?
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Old 09-16-2009, 05:34 PM   #10
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I hear ya guys. I guess i could lean the low end out. I am worried that i will wear out my sleeve so if it ever does get around 200 it will have no compression.

Just have to get a new P/s set when it wears out.
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Old 09-16-2009, 05:36 PM   #11
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Running too cold wears out the piston prematurely. When cold the sleeve is too tight, as the engine heats the sleeve loosens its grip, when the engine heats a little more, the piston expands and fits the hot sleeve. The piston and sleeve expand and contract at different rates, this is why final breakin at race temp is so important.

Allthough it is perfectly possible to be running at proper temps and have a cool head. Ex. airplane engines have never burned me. ( and use that stupid temp gauge for target practice allready. k?)

Can you post a pic of this "Mid" needle you speak of. The high end is on the brass fuel inlet post, the low end is on the slide near the linkage pivot ball connection. The mid is on the side of the carb and the idle is a tiny screw thats on the neck crooked.

Pretty sure you weren't supposed to screw with the mid! I don't think that "mid" needle really states what that screw deos very well!

Every mid I've messed got reset back to factory quick.

Last edited by Zerodefect; 09-16-2009 at 05:47 PM.
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Old 09-16-2009, 05:46 PM   #12
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lean your low end an hour at a time do a couple laps make sure your blowing a puff of smoke coming out of turns bring it in after a couple laps.If idle speed is high with break on, turn down idle screw.do this a couple of times leaning low end one hour at a time until you hit the 200's.
check your low end needle setting it sounds way rich.A good base setting is one full turn from flush.You are running way rich and engine life will be way short!
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Old 09-16-2009, 05:48 PM   #13
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Quote:
Originally Posted by Joey Platinum View Post
If your air filter is restrictive/very dirty/ very oily....it can effect the air to fuel ratio and thereby cause it to run rich in a situation where exact tunings on a different engine with a clean filter would run leaner. The same is true if your exhaust is restrictive.
I agree with Joey Platinum here - check your air filter and exhaust. Also, I haven't heard anyone mention weather and atmospheric conditions yet - where do you live? What's the weather like there? Humid or Dry? Hot or Cold? Altitude? Sea level or up in the mountains? All these things can effect an engine.
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Old 09-16-2009, 05:58 PM   #14
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+2 on the air filter. clogged air filters can do weird things. REAL WEIRD THiNGS!!!!!

I tried the trick where you use a strip of paper towel as a prefilter. That was interesting. Engine ran real goofy. Rich on low, lean on top, needed to crank the idle in a mile, tons of bottom end (even though it was pukeing smoke), no top (even though it leaned out nice) and it ran kinda warm. I wonder if that Rctech poster was just messing with me????

Lesson learned: Do not f with air filters. I use proline lowprofile foams, and use an extra foam prefilter. Filter oiled, prefilter oil, another prefilter stretched loose on top, unoiled.
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Old 09-16-2009, 06:08 PM   #15
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My needle settings are as follows, I use these settings in oval and offrad for truggy, oval, runtime doesnt matter, truggy 10 to 11 min 235 with an exergen.


HSN 3 turns in from flush
LSN 2 hours in from flush
Mid is flush at 3 oclock
7mm insert Nitrotane 30%
idle gap about 1mm

Idle's all day, tons of grunt and topend

Most of the JX's i have seen or tuned run very well with those settings, the modded button can change that but very little, mostly just a slighly richer setting.
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