What jet sizes did you use? I may have incorrect jets in my Mikuni causing the starting and idling problem. The person I bought it from had the recommended jets put in. I'm just covering all the bases. Any help would be great. Thanks.

 

As I said in your other post, when you get it torn down, post what you have.

 

I got that. SS124A is the one who put my jets in. He knows what I have before I even tear it down.

 

Well based on your profile that it is a 85gs, i would have to deduct that you have a 12a. Also deducting that you have a non-ported motor. The best jetting to start with is the following. MJ-200. MAJ-190. PJ-65 PN-60. This also is based on you using a good header system like RB. rx7doctor

 

Got everything right. I'll check my jets when I take it apart. I'm saving the ones you suggested on my comp. Thanks doc.

 

Glad to help. Your going to love it when you get it running correctly. Has very responsive throttle. Also make sure that you are using a good quality fuel pump and inline regulator for her. Need anymore help just pm me. rx7doctor

 

Hey, Doc ( and anybody else with an opinion grounded in experience )... As I've said many times on here, my 44phh isn't enough carb for the 4 port street ported 13B ( bogs ). I know the modded Nikki's aren't there yet, either. What do you recommend if I stay NA and unboosted ? Holley downdraft 600 or 650 or Weber 51 ? or what ? and please why ?

 

Thats a good question. Have you experimented with the Venturis at all on the 44phh? When you say it bogs, i take it that is off the line or a slight roll then giving hard throttle? rx7doctor

 

No experimentation. Yeah, it's funny in that if you are idling and give it WOT, it's fine, but I can't do any revving for several seconds before WOT or it'll starve/bog. When it does that, I have to nurse it past the bog, then it's fine again. But I think I need more A/F in the upper range, too.

 

It's hard to get acomplete smooth transistion from low to mid and again thru WOT.
Need to know what needle seat and jetting your using. rx7doctor

 

Damn ! I had to dig to find the file, but here goes:

Main Jet-200. Main Air Jet-240. Pilot Jet-62.5 Pump Nozzle-90 ( special order - largest ).

 

ok. I'll find my notes and give you some more info tommorow. I would expect that you are using a needle seat of 2.0 or larger. rx7doctor Forgot to ask. what fuel pump are you using and FPR at what setting?

 

I can't find that, but I just ordered and replaced the float needle seats last year ( was leaking gas into the K&N ).

Holley red pump and holley red fpr LOL. Set on 4.0 I'm certain.

Thanks, Doc !

 

Hey Grimes, I am running a 13b 4 port street port with a mikuni and I do not experience the same bog as you describe in your post. My set up seems to work fine with very similar jets as you are running, ( I would tell you what they are except I'd have to go out and take the jet cover off and look to see what air correction jets are in it, the mains are 190, the idle jets are 62.5 and the pump jets are 70, I have some of the 90's, did you know they come in long and short??)

anyway I did experience a similar bog experimenting with smaller main jets and that was one way I knew that they wer not good, they produced the same kind of bog you described.

my .02

 

Also your pressure may be to high, the mikuni book calls for 2.5 psi

 

Thanks, Watson. I'd sure like find out there's a remedy to this instead of "it's not enough carb for the ported 13B". I'm good with my entire setup EXCEPT for throttle response from idle.

Let me know if you come across the info.

 

Hey grimes, do you have extra jets for trail and error tuning??

 

Sorry to correct you on this. The 12a with a non-ported motor ran a psi of 3.0-3.5

the ported 13b should be between 4.0-4.5psi rx7doctor

 

No, but if anybody in the know leads me to believe that is what is needed ( since I believe I'm on the top edge of the jets range already ), I'd try to get some. Hell, they're easy enough to change out... top load and all

Yeah, I was told by Mariahmotorsports to run in the 4-4.5 range.

 

Morning David. Few things to check first. Recheck your float setting. make sure none of the jets are loose and especially check the pilot jet for blockage. I'll get back to you tonight with my notes when i find them. right now i'm off to pick up another accuired GSL. Good luck. rx7doctor

 

I searched around but couldn't find anything specific on the forums about this, so I'll just ask here. What's a good choice for a fuel pump and pressure regulator, and about how much do they run for? I'm a little tight on my budget right now, but I'm running a Mikuni with a stock FP and FPR so I want to get it taken care of. My parts car seems to have a an aftermarket fuel pump, but its condition is questionable. My engine is a non-ported 12A with RB headers and exhaust.

 

I have holley red pump and fpr, but if I had it to do over again I'd get a Mallory pump for the loudness issue. ( The reds are noisy as hell )

 

Get the carter P4060 for less money and it comes with insulator bushings to get rid of the noise. rx7doctor

 

Do you mean P4070? That's the one I have. Has three rubber bushings. Still loud though.

 

P4060 or P4070. I remember the trick i did was cut a piece of rubber to put in between the frame rail and the mounting plate. rx7doctor