I have owned a Qualcast B43 for a number of years and it's always been a bit temperamental, and that's putting it very mildly. I had it serviced about a year ago and it did improve the starting but now it's taken a turn for the worse and won't run. I replaced the plug, emptied out old petrol, but nothing. Garden centre guy suggested pouring some petrol into plug hole which I tried but it only seemed to run for about a second - I guess until the petrol ran out. So I'm thinking petrol starvation. Any suggestions would be very welcome but have to say, I'm not that handy with a box of spanners and a few screwdrivers. You know the kind of thing - easy to take it apart but then what, and I usually find that bit didn't need to come off or apart anyway! Here's hoping.

S T Rimmer, October 2008

Hi k3, thanks for latest info, but not been able to do any more at present as a bit busy. Will come back with update - thanks again.

S T Rimmer, October 2008

Hi, If you go into Ebay & enter walbro wt-526 in the search box it should find some examples! If not & it says '0 found' scroll down the left hand side of the screen to the 'location' box & click on 'worldwide' & click on search again, you should find several examples in the USA.
I doubt if you will find a wt-24 as I think they have been obsolete for a long time. But firstly I would double check your carb, it should have the model no. stamped on it, probably next to the fuel intake. So if it is a wt-24 & you think it is a fuel problem & have checked the other possible causes it may be worth trying a replacement. My machine is a Mk1 (1986), not sure if later models were different....regards

k3, October 2008

Hi k3, thanks for reply - all sounds good stuff to me, however I've searched high and low and those two carbs have not come up at all! Can you remember where you purchased yours. Many thanks.

S T Rimmer, October 2008

Hi, I have a 22 year old Qualcast B43 that has shown all the signs of petrol starvation. About a year ago I cleaned out the carb & replaced parts with a service kit with limited success! This year the same symptoms have appeared (problems starting/not revving properly/ cutting out). After ruling out other possibilities ( checking that a spark present/fuel line letting fuel pass but not sucking in airlocks or bubbles/ & checking air filter not clogged etc). I replaced the carb! This seems to have done the job! The original carb was a Walbro WT-24. I replaced it with a brand new WT-526 (a later equivalent), that I bought off Ebay from a supplier in the U.S.A. They are readily available with prices ranging from about £6 to £13 including postage. The only modification required was to remove the central plastic spline holding the air filter in place because the new carb has longer adjustment screws. I also blocked the carbs redundant fuel return pipe (below the adjustment screws) with the end of a wooden toothpick. Then a quick tweak on the fuel setting adjustment screws & the strimmer runs with more gusto than it has for years. I hope this is of help to you!

k3, October 2008