What am I missing. Carb issue

[original420racing]

96 spx runs Awesome with 2 zip ties
behind choke handle. ..lol

Pop off mid 20s both

New fuel lines

RAN on reserve directly to tank

CARBS cleaned 3 times

No change pull choke A little runs All day

 

[1of500]

Stock air box or after market flame arrestors?

Sent from my VS985 4G using Tapatalk

 

[original420racing]

Modified air box holes drilled some screens removed

 

[1of500]

What is the stock pop off setting mid 20s seems low [MENTION=77252]DRH[/MENTION]onda probably knows

Sent from my VS985 4G using Tapatalk

 

[original420racing]

I had them in the low 40s

Did the same thing.

I thought with box modified lower would be better

 

[1of500]

If you are pulling the choke to make it run right it's rich. I would get an un modified air box and go back to the stock pop off and stock jetting. Are there any other mods on the ski to justify modding the air box?

Sent from my VS985 4G using Tapatalk

 

[original420racing]

No its stock .

 

[original420racing]

I bought it this way I'm not great but decent with these carbs.always tuned with box of on stock or not never had one beat me up like this

 

[1of500]

I would take everything back to oem specs jets needle and seat pop off ect and put an unmodified air box on it

Sent from my VS985 4G using Tapatalk

 

[Mickirig1]

Like to old saying here says : If you want a faster Ski buy a faster Ski.
It's a real can a worms playing with the intake and carbs. They are engineered from the factory for optimized performance. Any change in one part is going to force changes elsewhere.

 

[Robj]

I think that because of your air box mods your jetting is too lean. You need to increase the size of the jets or go to a stock air box.

 

[original420racing]

I understand what you are All saying .but this ski ran fine for A long time AND then started Acting up.

 

[Shaw520]

If you are pulling the choke to make it run right it's rich.

Sent from my VS985 4G using Tapatalk

Just the opposite,... if its running better with choke on then you're lean,... I would be checking for air leaks (intake), or fuel/jet blockage.

 

[Austrian Rotax]

what are your LS and HS screws set at? sounds like you could have a vacuum leak, have you pressured check the fuel lines? did you use NEW carb base gaskets and make sure they didn't slide off when assembling? water separator o-ring replaced lately? the HS and LS adjustment O-rings always seem to get damaged from the carbs ive taken apart they are always squashed flat so it wouldn't surprise me if they are leaking air in your circuit as well but this is a last resort check.

 

[1of500]

Just the opposite,... if its running better with choke on then you're lean,... I would be checking for air leaks (intake), or fuel/jet blockage.

Sorry got turned around in my thinking by the low popoff

Sent from my VS985 4G using Tapatalk

 

[Mickirig1]

It's running lean. By pulling choke your erasing the air box and flame arrestor modifications. See Sticky at top for carb adjustments and theory.
Have you rebuilt the carbs? You have to figure the gaskets and such are almost 20 years old. Taking them apart 3 times and cleaning could cause a gasket to no longer seal. Could of failed causing the problem before cleaning. Do the tests for check valves and diaphragm test? The pop off tester can be used to pressure test the fuel system. Once I did it to mine, the gremlin could not hide any longer.

 

[Mekanix]

So What's the problem when you have the choke off ? How does it react?, Throttle response, Throttle position...

If your down to the 20's it should be more than rich enough. I've once had a carb that needed to be in the low 10's to compensate from clogged pilot circuits.

I've had this same issue with one machine I worked on and the only thing that fixed it was back flushing the pilot circuit. Some crap came out the back way with the pilot jet removed. I did also waste half can of carb cleaner in each carb but that did solve the problem. That machine would work ok but would also lean out just after applying more than 1/4 throttle. After the fix it was perfect.
This is an example of it worked fine and then gradually there was this problem without anything being altered by the user.

So what is yours doing ?

I think by applying choke, you are either effectively lowering pop off to non existant and the pilot circuit is just flowing what ever it can or its allowing the main jet to pull fuel and its using negative pressure (suction) rather than air flow. Once your above 1/3 throttle the main works on flow again.

Also you can get lots of spray from the pilot ports but it takes a while to get the right amount of clean so they flow properly.
And yes I'm in the cleaned carbs multiple times club until I started pouring the cleaner to it excessively!

 

[original420racing]

Lows are a little over 1 turn 0 highs

New card kits new base gaskets

With choke open it will take off fine for A couple of feet then want to Act like it's gonna stall

With two zip ties behind choke handle runs like normal
ALL DAY

PHONE IS BROKEN SORRY for jumbled letters

 

[Mekanix]

A quick test would be to open the low speed's up to 2 turns and see if that fixes the problem, If so, the pilot circuit is still clogged and that's just a way of dumping excess fuel to help compensate.

Can you run fine on the main jet? As in: did it run good once your past half throttle without the choke?
When rebuilding the carbs did you set the needle arm flush or bent down slightly?
If its too far bent down that will stop the needle from opening enough.

 

[original420racing]

No it will not run after half throttle with out choke

I will check.when I pull carbs tonight