Hi guys, I have a Redback (el cheapo) mower that was given to me, minus the air box cover and cartridge. This mower has the Chinese copy engine. Without the air box cover and filter the mower starts and runs fine, however, when I put the filter and cover back on it starts ok but just barely idles and won't rev up, when I remove the airbox cover and filter away she goes, it has the same symptoms when I remove the filter cartridge and just put the cover back on. I have stripped, soaked and cleaned the carby thoroughly blowing out with the compressor, I have replaced the manifold and carby gaskets and the manifold spacer is in perfect condition, it's got me stumped, and ideas please.
Check that the air vents in the filter box are not blocked. When the the motor is hardly idling and not revving is there any signs of black smoke from the exhaust ? this would indicate that there is an air flow restriction acting like a choke. Is the air filter box the correct one for that motor ? when it is installed does overhang the carby throat ?
In all honesty the front of the air box is from a briggs quantum motor, the front has been held on with a couple of cable ties. The previous owwner said he could not get an original front piece.
Could be the cause of your issue by the sound of it, maybe see if you can google an image of the cover to see where the vents are and replicate that making sure that the air entering the box will travel through the filter element. Can you put a fitting on the cover so you could run a flexible snorkel hose up high on the handle bars ? Sorry I can't be of any more help as I'm not familiar with that model. If it is a Sanli I'm sure a cheap one will appear on gumtree that you could rat parts off, plenty of them would have been sold.
Is it a pleated paper filter or foam? If the former, oil can sometimes block the filter - if it was clean oil it can be hard to tell (sometimes people try to oil them like a foam filter)
Try drilling a small hole in the air filter housing - just to see if it improves anything. Normally being the wrong cover would leave enough space for sufficient flow, but its worth a shot
I missed out on the dog. As for the Sanli air filters I do get the occasional one that is in as new condition but I could never justify buying one, they are just a stupid price
Hi guys, thanks for all the input, this thing never had a filter or front piece when I acquired it, it has a screw in primer so may be the same as the Talons, I have a heap of various spares from different mowers around the place, i'll make is a work in progress, thanks all for all the input.