I moved from about 20 ft in elevation to Colorado chillin at about 6700 ft.  my 87 sami sounds like its starving for either air of gasoline.  what i used to be able to do in 2wd without thinkin about it now can barely doit in 4low.  any ideas on what to do and or how to doit?

my first thought was the altitude compensator.  Did a search, and this was the only result, it may help you.

http://www.zukiworld.com/forum/general-suzuki-forum/running-slow-no-acceleration/

good luck

thanks man, i wont be able to work on it for a couple days but ill let you know.  i have always ran lowest octane gas in it bc anything higher user to make it backfire like hell, someone told me if i just ran higher octane it would fix it.  does that sound like something that could save me a weekend of tweaking the carb?

Maybe a little, but I wouldnt think it would make that much of a difference.

I lived in the SF bay area.....at or very near sea level.  I use my 87 sammy mainly for hunting purposes.  The country is 7000+ ft.  I notice a slight change in power and acceleration, but not the the extreme you are. 

Is yours bogging out?  Dieing? 

Ya, it just bogs down.  Im either revin it ao high that i burn the clutch to get it movin or i put it in 4lo and make myself content goin 5mph. 

Pull your plugs and see if they are fouled. If so you may be running in open loop, that is your emmision system is not working right and your carb is running in "limp" mode and flooding. Get an FSM and follow the trouble shooting steps. Basically, you get it warmed up and slide the little switch underthe dash that makes the check engine light come on, then run it at about 2000 rpm. If it starts to flash, then you're OK. But if it just stays on, you're in open loop :limp" mode and running very rich. Good chance the cat maybe getting plugged.

It revs fine like nothing is wrong, its when i put it in gear to drive it that it gets bogged.

if it turns out to be the plugs, is there a "best" or "worst" to get for replacements?

NGK Spark plugs.  They work, that's about all there is to it. 

ok...  next question, how difficult is it to rejet or do whatever i need to do to the stock one?  i saw somewhere that you can use a Harley carb instead of the stock one.  should the case be that i nee a new carb, how hard is it to switch to the HD one?

It' s a toss up.  The kit your looking for is the My Side, a lot of people like it.

so im looking at about 350 for all parts to use that HD carb, would it be cheaper to just go with a weber?  how much $/whats involved in re-jetting?

Have you replaced the fuel filter lately?

The computer adjusts your fuel mixture so re-jetting isn't really an sane option. There is a 'flow' control valve on the vacuum secondaries that you can remove and then your carb will open the secondaries sooner and possibly a bit more/further but this wouldn't be enough to fix what you're describing.

You will be down on power.... My first Samurai would barely do 55mph where I grew up which was 6,000 feet and then when I moved to about 400 feet it was fine at 55 and would do 70mph...

Did anything catastrophic happen like a bang or anything when you lost power? Have you checked ignition timing?

-Eric

i changed the fuel filter last week.  it just boggs down, best way to describe it is on a dirt bike after its warmed up and choke on puttin the hammer down it just boggs.  ill take it for a spin tonight and see if i cant think of a better way to describe it

i haven't driven it at 55mph or "highway speeds" as you describe in a few years and at low elevation it topped at 55, now i bet downhill i might could get it there

it doesnt really make a noise just acts like its gettin more gas than the air can handle.  i changed the plugs also but haven't driven it since those were put in

UPDATE:  Ok took it for a spin...  its still boggin down, meaning it cant handle a moderate grade in 2nd, it just gets to rich i think.  I got a Venturi tube http://rocky-road.com/venturi.html  with my SPOA yesterday so it'll be on hold till everything gets installed.  i saw that there isnt a screw to adjust how rich it runs but can i adjust that without droppin a big chunk of change?

p.s. thanks for the help!!
 

I'll be very interested in what you come up with because I've got the same thing going on with my new-to-me 87 Sammy.  I got it in a trade and some of the parts were installed, some were in the back.  I'm headed to AutoZone to pick up or order a carb rebuild kit.  The extra carb that came with it was supposedly a good off of a running car but was actually corroded inside and I had to pry the halves apart.

Mine will run and rev fine in the driveway, start to drive it and stomp it to the floor, it starves for fuel. Back it off (while still rolling) to about half-throttle and it will catch up and go to 3000 RPM (this is in 1st and 2nd gear in the 'hood).  My sensor light is always on, but does flash twice every now and then (haven't timed it yet).  I changed the O2 sensor because it was cheap and similar things happened to my boy's 88 Pulsar. I have a Haynes manual that came with the car (it sucks).  Where can I get an FSM?