is there some kind of emissions related switch in the tranny that may be linked to spark advance? if so, i'd be checking the wiring and or switch.

 

My Samurai does very similar to yours except the condition comes and goes. Does your engine have alot of miles on it? Mine has almost 150,000 on it, I'm living with the engine problem but I sure would like to fix it(rebuild or replace). I also run a stock carb that has been rebuilt. Maybe somebody has an answer.

 

im not sure if this is the answer but i was having a simliar problem, i had a dirty fuel filter and one of the plugs that hooks up the the carb vacume wasnt hooked up

 

Welcome to the world of Samurai.....to small a carb and to small a engine......

 

I'm not sure what it is either but my Zuki does the exact same thing. One day It'll really pull and I can do 75 without even having my foot to the floor and then the next day it struggles to do 60 or 65. I always thought that it was just the wind but now I know that it happens on days where there isn't any wind also. I live at a relatively high Alt. (4500') Is there something that is pressure sensitive in the carb that changes from day to day? All I can say is that I feel for ya' cause I know how it goes.



Remember the first rule in the Mountain Man Handbook: It's a long way to the hospital.

 

My early 88 Zuk after adding 30X9.5 tires literally died, couldn't get more than 55 at 2800 rpm/max. Added Calmini Headers with new Catylitic Converter now can get 70 no sweat. I believe the old Cat Converter was clogged. The combination of headers with 2 inch exhaust and new converter cleared it all up...

early 88 Zuk, 2" shackle lift, 2" exhaust, 30X9.5 rubber, Doetsh shocks & stabilizer