Box Stock

Yes I am super new

T

Tdub

New member
Ok I have a blue clone I got on a kart I bought. The motor is new. I started it and the carb was leaking a bit. Instead of cleaning and messing with it I bought a new one from box stock project. So I installed it and got it to fire up, but I have to give it a lot of throttle to keep it running. Is there some tuning I need to do? Air fuel mixture? I saw one screw with a spring on the outside, thought that might be air fuel mixture. The carb that was one it originally idled fine, but was a hauyi not ruixing like the new one. I know, really basic question but I know nothing about these motors.

Thanks
 
the old carb might have bigger idle jet like a 22 and main jet start at 38 and try that it should get u close if it is a stock motor but need more info
 
Is it a stock carburetor or has it been blue printed for a racing engine? If it is on a yard kart it probably needs the low end jetting opened up a little so it will get a little more fuel. That should make it idle better. If it is for a racing kart and has not been gone through it will not give the best results. Unless you have the knowledge and tools to go through it yourself and make it so it has the best potential to run the fastest on the track. You can not use the low end jet out of the one in the other, they are not the same size even though they look to be, unless it changed and I am not aware of it.
 
Ummm no one has stated the obvious answer. Adjust the idle screw. Should be a black screw that pushes against the plastic cap connecting the butterfly with the throttle linkage.
 
Funny I was thinking the gaskets might be blocking holes. I bet that is what it is. I reused the gaskets for the hauyi carb. Are they the same for the ruixing carb? Are there pictures of how they go on anywhere?
Thanks
 
Tdub said:
Funny I was thinking the gaskets might be blocking holes. I bet that is what it is. I reused the gaskets for the hauyi carb. Are they the same for the ruixing carb? Are there pictures of how they go on anywhere?
Thanks
Click to expand...

Should be the same gaskets for the two carburetors.
 
I know you are new BUT try looking at the carb,insulator,and block you may figure it out THEN you won't be NEW you'll be an experienced builder
 
If you have a aftermarket air filter and/or header on the motor it changes the jetting needs drastically. If it runs better with the choke part way closed then you need to enlarge the idle and main jets. Now if your motor is totally stock and you bought a racing carb pre-jetted for racing it could be providing too much fuel. We need more info.
 
I got it idling good now. Gave it a little more with the idle screw and once it warmed a little was good to go. Haven't drove it but it sounds healthy. Do you guys adjust the mixture screw at all? I don't know if the motor is stock or not. It is the harbor freight greyhound motor, has ARC stuff all over it. The guy was going to race it in the clone class locally, but decided to sell it. It came with a nice Top Kart chassis. Was an impulse buy for sure and seemed like a good deal after a little research.

Thanks guys
 
It's more than likely prepped for racing but depending on the year it was built it might be already out of spec. the rules are changing for 2014 so an engine built for 2013 will need to be gone over and brought up to spec. if it was built for 2012 rules then it for sure will be way down on power compared to engines built to the 2014 rules.
 
So now that you overcame that hurdle, do some research on the side cover bolts and use a high zinc content racing oil in it so it stays together. Sounds like it's an asphalt road course or sprint chassis? (Not offset oval?)
Who's rules does your track operate under?
 
I was going to practice with this motor and buy a new race ready one or build kit for the 2014 season if I decide I like it. I'm using Royal Purple in it right now. What is a normal break in process for these motors? I searched here, but not a lot of luck (maybe used the wrong words in the search). Yes, asphalt road courses are what I will be driving on. They tracks close to me use WKRA rules.
 
I've found the Royal Purple to be ok, not the best zinc content but their alternative for it seems to work ok. What is the angle of the motor mount?
I would go to the track or find someone that races there and ask them for the setup and gear ratio. Asphalt is hard on these motors and you've got to be on top of your engine for it to stay together. The best break in I had came from 10 minutes of idle and low rpm revs using some cheap 30wt oil, then change oil and I hit the track for my first practice session at about 1/2 speed with lots of throttle variance. Then change oil again and give it your heavy right foot. When I didn't do the 1/2 throttle practice session I raced all day and my rings still hadn't seated so I think it's important.
I actually run 5w-30 Maxima motorcycle synthetic blend in my clones, change after every hour of track time. I run a Trail Tech TTO($35) that tells me peak RPM after each session and hours so I can make sure I'm not over-revving and I know when to change oil.
The most important thing, is start out with a smaller rear sprocket than recommended and add teeth as you creep up to your target RPM. I was geared too low and in my first practice I floated the valves so bad down the straight from over-revving that the valves and keepers were chewed up and totally ruined, and had to be replaced.
 
rkcarguy thanks for all of the advice. The kart has a Mychron 3, so I can monitor the motor. What is a good safe top rpm and temp for these motors?
 
top rpm somewhere between 5400-5600 rpms. I can't remember temps off the top of my head but anywhere between 480-520 cht I think should be okay.
 
Wow...I'm running 6500 RPM's and start to worry somewhere north of 435 degrees CHT. Maybe I am wrong though...I have been known to be so once or twice a year :)
 
Tdub said:
rkcarguy thanks for all of the advice. The kart has a Mychron 3, so I can monitor the motor. What is a good safe top rpm and temp for these motors?
Click to expand...
A typical 'stock-class' road course Clone on a 1/2ml track at 360-370lbs will/should be geared 'abt' 4.0 and turning 'abt' 63-6400 @ 390-420*...(in-general)! That 'would be'...Good and Safe! There is a-lot too learn from that point.
 
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