tuning rx2 1974 hitachi carburetor
 

I am having difficulty tuning my hitachi carb from an rx2. It seems to be leaning out. I have messed with the adjustment screws, but if anyone has a diagram or anything that would help me much. There's a big flathead screw in the center (don't know what it does), a 10mm screw (might be the a/f mixture screw) and over by the throttle linkage there's a smaller screw with a flathead insert for the idle screw only. But I don't know how each should be set. Normal driving is a bitch. It seems to be leaning out just driving normally partial throttle. It will stutter unless more gas is applied. I managed to richen it up so when WOT it doesn't stutter, which it used to. Please any help is appreciated. This new carb is crazy difficult to tune compared to the nikki. Thanks

I rebuilt an Hitachi last week and it ran very smooth even before adjusting any screws. Maybe that carb of yours needs a rebuild?

By the way, the Hitachi carb is for a 13B. Does your RX-2 have a 12A? If so, just get another Nikki (maybe from Sterling).

If you decided to get another Nikki, would yopu be willing to sell the Hitachi? Do you have any pictures?

probably does need a rebuild. from what i can tell its seems that the car stutters so maybe a theres not enough pressure forcing the fuel out of the one jet. one is flowing more at idle than the other.

yes its a 12A i still have my nikki in my rear hatch, as well as tons of water just in case anything goes wrong where i need to do a carb swap on the highway or something

i would sell the hitachi IF it was mine to begin with, i put it on to test it out, im on a trial period. if i liked it then i might buy it. it seems that this one is too much of a handful im gonna have to go back to stock nikki and my original clutch fan im sure. lame

and sorry no pics. =(

why woudl ypou have to swith back to your original clutch fan?

Ok I thought it was listed, but I'm in arizona constantly in 100-120 degree weather. The e fan I have installed doesn't cover my entire shroud thus my cooling is pretty shitty.

why not buy a better e-fan? should be better than the stock fan, well i would think at least.

This isn't helping. I need a diagram of this carb to find what the hell I am tuning here. Does anyone have one? Does anyone know who has one? Anything. I'm running out of options here.

And matt22, I don't have money for an efan, I need help with the carb, I could care less about the fan.

where in Az are you?

Avondale

You need to pull all the damn cacti out of your carb!


Make a mark to see where the screws are, and try messing with them. If you're lean, then un-lean it.

yeah man "un-lean" it.

Yeah, make fun of my terminolgy smarts :D

Guys don't whore my thread I need help. Lol

OK, I talked to tougeFB on aol, and I told him that I thought that there might be some old gunk or some sort of buildup in the jet or possibly in the fuel line itself that could be causing the restriction. I am not sure how the Hitachi carbs are set up but if it is anything like the nikki, then this seems like a possible culprit to me.

And the Remedy is...........

No help? Bummer. Bump

If you having spotty performance on a carb you've never rebuilt, you need to rebuild the damn thing. It'll take you an afternoon at most, will rule out the whole "junk in the carb" possibilty, and let you look for stuck, broken, or misinstalled hardware from a previous owner. You need to take it off and go through it. It won't take long.

stop whinning & have a play with it - its the only way to really learn & you may drop your balls doing it.


ohh, and the 'not enough fuel pressure' bs that you wrote earlier, it is a gravity/vacuum fed carby - as long as there is fuel in the bowl & no blockages & there is suction through the venturies - then you will have fuel entering the manifold/motor.


the hitachi's are a good (stock) carby (as are the nikki's) - make sure your secondaries are opening (this applies to both makes)


if the g ggur gur gur stuttering is when you are taking off/accelerating, then you may need to adjust the accelerator pump. get it idling nicely before you start playing with it 1st

have fun :rlaugh:

I have a couple truck hitachi's....
 

I have a couple Hitachi's from my truck collection, dying to do the Nikki mod set up on a RB mani... Will it still have good results. Thinking long runners is good thing...