Outer Limits 4x4 Board

Hi - first time here, hope you can help me. I have a '91 LWB GQ and the original NIssan carb has a problem - one of the internal airways is partially blocked (probably by corrosion) and so far we haven't succeeded in unblocking it.

(1) Any bright ideas for unblocking it? It's not a straight passage.
(2) Any suggestions for a replacement carb? Best to get the same again or if not, what do you recommend?

Vehicle is used extensively offroad, had a Holley 4bbl before but it was a nightmare to maintain and didn't work well at any angle. So I've gone back to stock carb for now. Head is ported and polished and have stage 2 cam and headers.

Thanks in advance.

The stock Nissan carby (Nikki) has a vaccum secondary throat. Just incasue you aren't sure what that is (sounds like u do though) is that the Primary butterfly is run by the throttle cable commeing from the accelerator pedal, the other is run by a link hooked into a vaccum. In theory when the vaccum raises when the rev's pick up, the 2nd throat is supposed to open up, however, it very rearly works properlly if at all. and when the revs die like heading up hill, the secondary throat closes off first and a loss of power is a result.

Most people who take the carby setups serious go and have them modified that the secondary throad runs on the primary linkage at a special rate. this bypasses the vaccum and allows you to keep both throats open all the time under acceleration and up hill climbing

hey mate not sure what state you are in but nigel from the carby shop in wantirna recently rebuilt my carby and modded the secondarys so that they no longer use the vacum to open they now open slightly earlier. The result was a noticable increase in performance and my car runs heaps better than it did before, also i have had it on some rediculouse (excuse spelling) angles and it runs great total cost for full rebuild and mods $297 + $25 for extended rotor button end result really happy
ohh and since the rebuild i have gone from 31's to 35's without changing diff ratios and am actually getting better economy than before the 35's

Thanks for the input, much appreciated. The vacuum secondary choke seems to work well, once you get enough vac to open this it pulls pretty well. I reckon it's the primary side that has this bloody airway which is blocked, because there's very poor pickup till the secondary gets going.

So are you saying that the secondary choke is now fully mechanical? Sounds like a good improvement. Only one small problem: I'm in Dubai (Arabian Gulf) and your carbie guru is in Oz. Can you give me his contact details/email addy? Maybe I could send him mine (just the carbie, not the whole car:-) and let him work his magic on it.

yes it is fully mechanical give me a few days and ill post you nigels details he is an absolute guru does really goood work

mudmav

I'd be interested in his details as well. I'm having similar probs.
Cheers

Found it thru Google:

The Carby Shop
5 Sherwood Court
Suburb WANTIRNA SOUTH
Postcode 3152
State VIC
Phone (03) 9801-3984

Phoned them the other day, got a recorded message that they were on holiday till Monday 26th.