fuel tap primer

terry274 · Post by **terry274** » Thu Jan 01, 2009 5:10 pm

I am having trouble with the cold start primer on my Super Dexta. I can remove the valve going into the heater manifold and clean it and it will work once or twice. But after a few pumps it will be clogged again. The rubber surrounding the push button is badly deteriorated and I am wondering if that is somehow getting into the fuel line. The fuel tank is about 3/4 full and I can't see if there is anything in the tank. When the weather warms up I will drain the tank and see if it needs to be cleaned.
Has anyone else experienced this problem? I have been reading Stefan Riegel's web site where he gives instructions on making a new primer out of a Stihl trimmer bulb. This looks promising, but I am afraid to try and take the fuel tap apart as I might never get it back together.
Thanks, Terry

Post by **Brian** » Thu Jan 01, 2009 7:07 pm

Sounds like you have got gunge in the fuel tank and the fuel tank filter is either missing or damaged. The filter that fits on the tap itself, in the tank, should prevent blockages in the primer.

terry274 · Post by **terry274** » Thu Jan 01, 2009 7:11 pm

Thanks Brian, I will drain the tank and inspect the filter.
Terry

JohnG · Post by **JohnG** » Fri Jan 02, 2009 6:01 pm

Hi Terry

I have had a similar problem with the primer pump. Had the tank off and cleaned it, fitted a filter in the tank and renewed the fuel lines but it still only works intermittently, say once or twice every ten pumps.

I have come to the conclusion that a new primer pump is called for. Having searched the net there are a number of suppliers offering them but at widely differing prices - is this the same pump at different prices or are there a number of different makes - if the latter can anyone recommend one which works.

Thanks

John

terry274 · Post by **terry274** » Sat Jan 03, 2009 10:35 pm

I took a flashlight and shined in the tank. I can see a screen, it does not appear to be damaged.
On page 20 of the service manual the manual says
"The fuel tap valve seals can be replaced with the tap in position by removing the valve retaining spring and unscrewing the valve from the body."
But I can find no retaining spring to remove. I suspect that the retaining spring was on the older models, and was done away with in the sixties. If this is not correct, can someone explain how the primer is disassembled?

[edit]
OK, I inspected the tap closer. The manual is refering to the shut off valve, not the primer pump. The pump in not meant to be taken apart.
Thanks, Terry

terry274 · Post by **terry274** » Sat Jan 03, 2009 11:48 pm

JohnG, Agriline is probably your best opportunity for a new tap.
http://www.agrilineproducts.com/dexta_cart.htm
Terry

aldo · Post by **aldo** » Sun Jan 04, 2009 2:03 pm

Hi there Terry,
the valve/jet going into the manifold can be dismantled, there is a small collar holding the spring and ball bearing in place. I removed the collar with an easy-out, cleaned everything, then reassembled -after cleaning, I found it still needs quite a bit of pressure to get fuel through, probably because the jet size is so small. So maybe your old primer pump has leaky valves or something, and just doesn't have enough pressure.

terry274 · Post by **terry274** » Thu Mar 05, 2009 12:54 am

I bought a new fuel tap from Cross Creek Tractor in Alabama. Took the tank off and cleaned it. My tractor starts a LOT better now!
One thing I noticed, according to the owners manual you should have a fuel reserve that can be used by opening the tap more than two turns. But the tap I bought and the old tap I removed did not have a pipe sticking up inside the tank. So how could it have a fuel reserve? How could the tap "know" when the fuel level was is down to a certain point?
Terry

aldo · Post by **aldo** » Thu Mar 05, 2009 7:36 am

My reserve seems to work, but there is no pipe sticking up inside the tank. When I had the tap apart, i figured out how thew reserve works, but forgotten now.