Outer Limits 4x4 Board

Refering to this on the Low Range Offroad site:


It says:
"Venturi Tube
If you are running a stock carbureted motor, you have a easily fixable problem. Suzuki should have put this part in from the factory but caught it to late. "...Samurais may exhibit a hesitation/flat spot, in any gear, when in acceleration from partial to open throttle." Your Samurai has or will have a flat spot in carburetor. When you are at an idle and you floor the throttle it will hesitate for a moment and then continue to rev up. That hesitation is what you want to get rid of. The reason for this is it causes a vacuum in the fuel bowl. This venturi tube catches some of the air coming into the engine and forces it into the bowl eliminating the flat spot. Super easy to install and only takes about 5 minutes.

Price: $11.00"

Now I never had a drama until I had my carby (stock Aisin) rebuilt and tuned just recently. I put it back on and the gasket leaked so I pulled it off and cut 4 x gaskets out of gasket paper (two for each side of spacer) along with plenty of goo to ensure it would hold and it has, no dramas.

But now when I go to accelerate I have a noticable flat spot for at least a second. Both when taking off from neutral and when accelerating from coasting in gear.

It happens at low RPM (~1000rpm) and doesn't occur anywhere else in the rev range. So is this what they're talking about? It never used to do it at all.

Would like to get it sorted in the next couple of weeks before I leave for Fraser Island. Can you buy this part locally anywhere or is it worth getting them to airmail it over to me?

Pull the carby apart again, clean off ALL the 'goo' you used then, find the right gasket and put it on DRY. There is a reason the gaskets go on dry....

The U.S market got a different carby to us so the Venturi Tube 'fix' doesn't apply here.
Jas.

want33s wrote:The U.S market got a different carby to us so the Venturi Tube 'fix' doesn't apply here.
Jas.

Yep. Check your accelerator pump linkages, and make sure the piston is working properly. Look down the throat of the carby and quickly twist the throttle (with motor off) and make sure there is a squirt of fuel going down the throat.

Layto....

hey yeah my sierra is hesitating at low revs too (950 - 1300) will stall if i just put my foot to the floor!!! but if i just tap it constanlty and gradually get it to rev higher than 1300 it goes fine...

why would it stall from accelerating from take off??? only happens from a stop start while driving its fine...

islandvit

ScrawnC wrote:Pull the carby apart again, clean off ALL the 'goo' you used then, find the right gasket and put it on DRY. There is a reason the gaskets go on dry....

So if there's a reason they go on dry why is gasket sealant even sold?

Jas and Layto, thanks for that information. I'll have another look at it tonight.

4130warrior wrote:

ScrawnC wrote:Pull the carby apart again, clean off ALL the 'goo' you used then, find the right gasket and put it on DRY. There is a reason the gaskets go on dry....

So if there's a reason they go on dry why is gasket sealant even sold?

Jas and Layto, thanks for that information. I'll have another look at it tonight.

Gasket sealant is for sumps, rocker covers, gearboxes etc.
Not Carby's as fuel will dissolve the sealant. Bad news if you have a catalytic convertor or an O2 sensor.
Carbys ONLY use a paper or nitrile rubber gasket.

That sort of hesitation can be a few things but I'd check ignition timing then float level and accelerator pump in carb.
Jas.

Carb's quite often have little breathers that run down the wall of the carb, when you use a sealant these little breathers are then blocked with the sealant. If there was no problem before you pulled it apart and now there is then the best place to start would be to remove all the goo and find the right gasket that fits. If that doesn't fix the problem then start looking elsewhere.

Ah, right. Okay, thanks for the info, I will have a play around this arvo and see what I can find out.