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Old 11-25-2008, 10:40 AM   #1
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Default Engine too lean or too rich? I can't tell!

So i finally got my 5 year old engine to fire up yesterday. It was sitting around for 4 years so i had to unfreeze it, replace some parts, etc. But now that i've started it up, i'm confused as to if it is too lean or too rich. The engine i have does not have a low-speed needle, only idle screw and high-speed needle. When i start up the engine, it dies at idle after about 10 seconds and gurgles up (too rich). It does the same thing when i hit full throttle, except it dies after a few seconds so it's got to be too lean. So i adjusted the idle screw to open up the carburetor up so much that the car moves a little by itself at idle. But it still dies like it's too rich. Now i think the engine is flooded since i can't even pull on the cord to start the engine, it's stuck. The only way i can pull the cord is if i take off the glow plug, but i hear leaking sounds near the clutch of the engine. What's going on here? So many mixed messages!

P.S. The high-speed needle is 2 full rotations out (counter clock-wise). I know it's supposed to be in the 2-3 range, so i backed it out 1/4 way and it wouldn't even start. Also, the glow plug and combustion chamber seemed to have slight burn marks in them (brown stains on piston and glow plug).
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Old 11-25-2008, 10:52 AM   #2
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If you are hearing leaking around the front of the engine your front bearing or carb could be leaking. an air leak like this could also cause some of the problems you are having.
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Old 11-25-2008, 10:55 AM   #3
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I would say your bearing are all shot! 5 years = lots of rust. Take it apart and inspect it. It's probably leaking like crazy from everywhere. Locked bearings will also make it impossible to pull the pullstart, and airleaks mean you will never get it tuned right.
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Old 11-25-2008, 12:03 PM   #4
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Ughhh great, now i don't know if i should sell the car or not. I don't want to keep it since it's the original HPI Nitro RS4 MT and all the parts are discontinued, which makes finding replacement parts or even aftermarket parts that fit difficult / expensive. But i want to keep it because i want to have a nitro rc.
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Old 11-25-2008, 12:13 PM   #5
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You can try fixing the engine, or put a new engine in it. Engines are only about $100 for that car. Chances are it needs lots more work though. In order for you to enjoy it, you should rebuild the shocks, and the diffs, and replace all the cars bearings. It's not worth more than $50 to sell it, might be cheeper in the long run to fix it....Good luck
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Old 11-25-2008, 03:32 PM   #6
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I had a hpi rush years ago that had engine in it with a flat head and a one needle carb. I was new to rc and blew it up so I sent it in to hpi for repairs but in the meantime bought a os engine to run in there. I have had that engine laying around for quite some time now and never ran it. If you wanna buy it I will sell it to you for $25 shipped to the lower 48.

PM me if your interested.
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Old 11-25-2008, 04:27 PM   #7
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Hey i'll keep that offer in mind. Which OS engine is it? I'm just worried that ill blow all this money on the car, then break a drivetrain component or something and find out no after market parts fit it.
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Old 11-26-2008, 10:11 AM   #8
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No it isnt he OS engine it is the rebuilt factory hpi .15.
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Old 11-27-2008, 02:36 PM   #9
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I can't believe it, i actually got the engine going. It's running beautifully right now. I think it just needed some oil to seal any minor air leaks.
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