finding golden sand like crystals in carb??

[vw lee]

can anyone out there help me out? I recently (nov) bought our first van so my knowledge is very limited.
I am having problems with the van ticking over, it will start fine but to keep it running i have to keep it going on the throttle so I thought mybe a fuel issue so I stripped cleaned & serviced the carb, but while cleaning it I found small sand like crystals in the float bowl. clean carb fitted van turned over and ticked over fine for about 3-4 minutes then cut out again after head scratch & giving Rob a electric shock still no joy so carb again removed to find more of these sand like golden crystals so I think these maybe the problem.

WHAT ARE THESE CRYSTALS???
IS IT OLD FUEL, FUEL LINE BREAKING DOWN?? PLEASE HELP I NEED MY VAN ON THE ROAD......

[NicBeeee]

Hi,

Sounds like it could be evaporated fuel if the the carb has not been used for while

Nick

[fairwynds]

....WHS /\ /\ /\ /\ - it'll be old, dried out fuel, and you will have to strip the carb down to jets, and ensure every scrap is out. You can buy carb cleaner to soak the jets in. I had same issue with a brand new boat oatboard, which after using it the first few times, I placed in a 'drying 'room, which simply evaporated the fuel in the float bowls and when I next used it the crystals were sucked through the jets, blocking them completely! Doh! Good luck...

[vw lee]

thanks for replies. do you think I will have to clean the petrol tank out?? If so what is the easiest way to go about it.

[what2do]

Hi, if you're competent enough to strip and clean the carb, then I would avoid 'carb cleaner' as it's pants since the nasties were taken out due to environmental concerns. A far superior stripper that will remove the varnishes, etc without doing any damagae to the rest of the carb is good old coke - cherry, diet, coca cola, pepsi, panda or whatever tickles your tonsils! I've been cleaning 2stroke motocross carbs using this method for years. A real eye opener is when a carb is cleaned using ultrasound, the removed debris is often enough to fill a thimble. I keep meaning to ask my dentists if they'll allow me to clean my carbs in their machine - she's a bit hostile at the best of times so perhaps I'd better not lol. Mitch.

[vw lee]

the carb was fully striped & cleaned but its on my bench ready to be done again tomorrow.will try the coke in the float bowl, how long do you leave it soaking? fingers crossed.

[ELVIS]

Is it very obviously sand or look like sand when viewed in a cup/beaker with petrol in aswell?

Let me explain...........

Me oppo is having running problems and drained his filters into a clear plastic paint measure beaker, he also drained some from bottom of tank.

In the bottom of the two beakers there was what looked very deffinitely like sand crystals. On closer inspection (held up to light and viewed beaker from underneath) the sand crystals were actually very small beads of water that were discoloured due to the water causing oxidisation/rusting and this holding the dirty coloured rust. If the beaker was tilted very slowly SOME of the water beaded into bigger droplets, not many though.

Just an idea

[vw lee]

Cheers Elvis, another possibilty that might be worth looking into.

[what2do]

Overnight in coke is plenty, it'll be shiny like a new pin - can't guarantee that you'll go any faster though!

[monkeyboy]

I had a problem like this turned out to be the timing was slightly out!... good luck

[vw lee]

carb cleaned (again) & refitted, van started straight away but only ticked over for about 3 minutes then died again. tried to start it again and unless I kept on the throttle it just died, won't tick over, So I disconnect the fuel inlet on petrol pump and pumped fresh fuel out of jerry can and yet again ticked over for approx 3 minutes the died again but would tick over unless I kept on the throttle. so don't think it is petrol tank or fuel line.

Next I will be checking all hoses, they appear to look ok but not to sure how you check the braided ones as you can't see inside them??
then timing??
still if no joy the fuel pump rod as I have read in earlier thread, but how do I check this can anyone tell me??

[what2do]

Your symptoms to those often found on motorbikes where the float in the carb is set up wrong. The engine starts because the bowl is full but over the next few minutes it stops due to it being starved of fuel. Often the float sticks in the up/full position which doesn't allow sufficient or any fuel in to replace that which has been used in the first few minutes of running.

Hopefully, someone can translate this into something more relevant to your carb. Fingers crossed.

[vw lee]

I'm with you on that one as I have experienced simular on the carb on my old vespa I had, have checked the float though & it is nice and free.

I'm reading more & more on here to find the solution but not really getting anywhere........ All suggestions welcome.....I'm not totally bald after all the head scratching.. (he looks a bit like me)

[kevtherev]

After three mins from cold the Auto choke is almost off.
Is the mixture set OK?
too lean and it will stop
Air leaks on the induction side will also cause this effect
faulty pump will cause this.
Water in the fuel will cause this
poor or clogged fuel filter will cause this

[vw lee]

Its had a new fuel filter & I have pumped fresh petrol directly out of a jerry can & still the same. the mixture screw was moved ( not by me) so thats a possibility. Is there any way of testing the pump is working properly? where abouts would i check for leaks on induction side?

sorry for silly questions but these engines are all very new to me but you have to start some where.

If you don't try you will never learn. thanks for the advice all of you, I owe you a beer if I ever get on the road