slowpokeRRR

iTrader: (4)

every since day one when i blew my starter box trying to turn it over i should have known it was gonna be a problem. i have had some of the fastest guys at my track look at this motor and at my car they all give it back with the same recomendation you should have bought the p5. the motor has less than a gallon and it runs like it has 10 gallons it runs like a champ for about to tanks then it starts to bog as if it has lost compression then i bring it in and kill it check plenty pinch. ive tried clutch after clutch hoping it just clutch drag with no success. if theres is anything you can think of i wanna hear it. also can someone give me mugen contacts info so i can see about sending them the motor back,and if they have local rep who may can help me (south florida)

sport10

Did the motor ever run right? With only a half a gallon this motor might still be breaking in. Some motors are tempermental till they break in then settle down. Also, did you replace the glowplug after break in? Are you using the correct amount of head shims if you are using 30%? Is your fuel fresh? Have you checked the fuel and muffler pressure lines for leaks? There are alot of things that can make a motor run bad other than the clutch. Go through all the checks before you blame the motor.

sport10

Why don't you see if someone will let you temporarly borrow a know good running motor and swap it with the Ninja. That will let you know if you have problems elsewhere like the fuel system.

MonkeyWrench

1. My 421b does the same thing. Here is what Ive discovered. It Runs great for the first 6-8 laps then as temps come up bottom end bogs and leans out, Then it comes off real hot. Ive found with most of these motors in order to get it to run right at race conditions it runs rich for the first 3-4 laps and then comes in. 2. Make sure you have fresh clutch springs in cause these engaging to early will mock a bottom end bog too. "Clutch coming in before power band". Good luck.

nutfluff

iTrader: (5)

I have two of these and they run great...a lot of pinch for the first gallon and I needed a heat gun to get them started at first! Did you tighten the carb when you got it???...It comes from the factory a hair loose and you may be sucking in air....also they like to run hotter than you average mill...240-260 is prime...(per the Mugen drivers at Rev Raceway in SoCal.)

mremtr

iTrader: (1)

The engine is still new and breaking in ! As for killing starter boxes , heat the engine up ! You need to check you tuned pipe ,and see if it is ok as well. make sure the internals are good and the pressure fitting is open. Also you need to make sure you have the correct pipe and manifold ! Check the carb too . If the engine runs too hot richen it up ,they won't make any power when new .

slowpokeRRR

iTrader: (4)

its hard to say weither it ever ran rite i mean during breakin i never really ran it hard or long enough to see it do what its doing now. no its not the factory glow plug for that matter ive tried nija plugs nova 6's 7's and 8's now im back to a os p3 and the timing sounds so much better. ive taken the motor off and putting it on another buggy to see if it runs better. i am currently using a jp2. i am waiting on a new gas tank just as a precaution but i dont know what eles to do!

Dave.H

iTrader: (2)

First of all that's the wrong glow plug run a ODonnell 77 turbo.

mremtr

iTrader: (1)

Did you check that pipe yet ? I had trouble with the JP2 pipe at the pressure fitting . If this is ok , then you need to finish running in the engine first .
If it has really good pinch this is a good thing . Get the engine started and ajust the low end so it has decent idle and throttle resonse, decent now not deadly !!! Now your ready for some break in time . Next you need to ajust the tope screw so when you sqeeze full throttle the engine will go VERY RICH ! And acctually slow down ,and pick up as you let off. At this point it should be faster at half throttle than at full throttle!! Run it like this for 20 or more tanks !! That will equal almost a gallon of fuel. You will notice the engine will get faster and faster as you go through the tanks of fuel , when it gets to a point where the engine doesn't want to idle, turn it up and start to lean out the top end ,only lean it a tiny bit at a time !!! AND ONLY AJUST IT AFTER IT IS AT 200+ degrees of temp ! Or you are sure to get things too lean . The longer it takes to run in the engine the longer it will last! I get an average of 14+gallons with only a slight pinch and a rod change at 10gallons.
You always want to SNEAK UP on a race tune !!
Oh and you can race the buggy all the time your running it in , just remember that you DON'T WANT TO RUN OUT OF FUEL ! And you must not try to lean out the engine yet . IT will come around when it is ready TRUST ME !! I've been doing this for over 20 years !
As the tank gets low the engine will of course go lean , this is ok as the entire time you are heat cycling the engine

Howard C.

iTrader: (1)

I run a o.s 2050 pipe with the ofna silver aluminum shoes with two 1.0 springs and one 1.1 spring as for plugs I run the o.s p3