STP Carb Spray

[Octopus]

OIC......1 can of carb spray can be use for how many application? Could you describe what's the difference you felt after a carb spray treatment? Am interested to know more about this stuff......... Thanks.

[Unknown_G7]

1-2 yrs shouldn't be any problem for using every 2-3 months. If you are still using the stock air filter then you can spray it every 6 months. After that the car will run much more smoother.

[Octopus]

Thanks, will get one and try it out. I'm still on stock air filter.

[Sheltie2306]

Don't think you start engine. Spray with engine off.

Then will have a hard time starting the engine. Once started, rev the car like crazy at stationary, will see lots of black/white/grey smoke, rev until eveything clear.

[Octopus]

Sorry, just to clarify......you mean I should spray the carb spray into the carburator while engine not running. After using the carb spray, then proceed to start the engine and rev it hard?

 

I always thought that the engine must be running first before using the carb spray.....this method no good?

[Sheltie2306]

I did it almost 5 yrs ago on my old Honda Accord. I remember I read the instruction on the can and did it that way. I remember the instruction said spray, wait for 10 minutes to soak, then start engine. However, I suggest you read the instruction on the can to confirm that. I did remember that I had a hard time starting the engine after the spray, had to crank for quite a few seconds before engine started.

[Octopus]

Thanks for your advise. Will read the instruction before trying out. Even if need to spray into the carburator before starting engine, I'll probably spray minimum to be safe. Wouldn't want to call the tow truck if my engine cannot start after a carb spray treatment.

[Unknown_G7]

You need to spray when the engine is running. If not after that you'll have problem getting it start.

[Ghostrider]

You need to start the engine and rev it higher then spray...do not let your engine stall....spray until all the varnish on your carb is gone. Keep revving until all the smoke from the exhaust clears.

 

If you spray with the engine off, you will flood the carb. Hence you have problem cranking the engine to start.

[Pisces69]

how to use?

just spray on the carb?

what's the purpose of a carb spray?

==================

 

Read the instructions on the can but most carb sprays r the same although 1 type i used can even spray into the petrol tank.

 

Usually u spray liberal amount into the carb ( after remove the air filter) & let it soak for several minutes to dissolve the hard varnish & gum accumulated from all those years of neglect.

 

Then u try to start engine, but you must blow the accelerator & crank for say 5 seconds at a time until the engine fires up.

 

Firstly it will be like a sick engine sputtering to life but keep blowing the accelerator to get the engine running at about 1.5 to 2 K rpm.

 

Once engine running smooth & normal, adjust idle speed to about 2K rmp & spray intermittently into the carb ( trying not to kill the engine as u go).

 

After about 10 - 20 seconds just blow engine hard to remove any excess residue from the system & re-adjust your idle speed back to it's original speed & you're done.

 

Put the air filter back & if u got time, take the car for a short & lively spin to further remove any remaining carbon on the valves & pistons.

 

Enjoy your ride after that.

Edited February 15, 2005 by Pisces69

[Esky]

Izzit ok to just spray lightly onto the fuel jet exit, and let it sit for a while b4 starting? I suspect my Iswara's carb's fuel jet is having gum build-ups, and therefore after cold-starting when the ambient temp is low the idling is very rough. But no problem when the ambient temperature is high, even if cold-starting.

[Pisces69]

If u mean the Venturi? I think it's no problem but it will also settle in the float tank where most of the sludge will build up.

 

I normally spray the butterfly valves & work down to the throttle body past the venturi & spray a liberal amount into the float tank.

 

I also use it to spray the outside of the carb to wash off all the black goo that gets stuck on the outside of the carb & cleans the linkages & springs too so they work smoothly. Lightly oil the moving parts after.

 

The carb looks almost like new after a good spraying.

 

U can also get your good mechanic to do a "Carb service" by dismantling & cleaning the inside throughly.

 

Better yet is get a "Carb repair kit" with all the little bits & pieces & ask him to change all the parts inside with the kit.

 

Make sure your mechanic is experienced though. If a young, in-experienced guy does it, that's the end of your carb.

[Esky]

Yeah, venturi, that's the one!

 

Spraying into the float tank.... u mean u spray it straight into the float tank's venting holes, right?

[Pisces69]

Yup.

[Yangster]

Carb cleaners are good stuff and effective but Just dun spray too much into the carb as it may flood your throttle body. my cousin did that on his old car and.... gotta crank damn long before engine started and a small explosion occured soon after. heard a loud pop with grey smoke coming from carb....luckily no damage and lots of black soot came out from exhaust

[Unknown_G7]

That's dangerous

[Silver_blade]

I tot that's normal. No?

[Pisces69]

I think the "POP" was the blow back from the cylinder misfiring only.

 

The "smoke" was the vapourised fuel/air mixture pushed back our of the carb by the pressure.

 

Might have a sticky valve. Cud b due to carbon or worn valve/guide/spring.

 

Just run engine after u finished spraying & take it for a spin & see if got any problems after.

 

Just make sure u put everything back as how it sud b b4 u drive off.

 

Sud b OK most of the time.