[Ged]

I have a 13hp Honda engine powering my pressure washer. The problem is as follows. When on tick over it runs sweet but when I put some revs on the engine is reving up an reving down as if it can’t decide whether its got enough petrol. It doesn’t stall but it is definitely not right. You can see the throttle linkage moving back and forwards on its own. When I apply full revs it is not as noticeable. Guessing it is fuel problem. Would like to attempt fix myself if possible though I’ m not a mechanic. Any advice please.

Regards Ged

[Blast Off Stoke]

not really mechanically minded myself but have you checked air filter,plug and checked the petrol reservoir bowl thingy for dirt.This is the round silver bowl shaped part,it does have a drain screw at the bottom so unscrew that and see what comes out.If you decide to take the complete bowl of you may / will need a replacement seal though so be aware .Also make sure the choke is on although not sure if it would at all when warm with it on.

[BDCS]

Yes it would be a petrol related problem. There are two 10mm headed bolts on the bottom of the float bowl - one in the middle and one offset, the one in the middle holds the bowl on and the other is the drain. Remove the drain and then turn the petrol on which should be a healthy flow, if its not then the filter in the tank is blocked which can be seen through the filler hole. The filter can be blown clean from the filler or it unscrews from the bottom of the tank once you have removed the fuel hose.
     If you have good fuel flow the it may be crap in the jet which you access via removing the screw in the middle of the bowl, once this is out then if you are careful you can save the seal or even unscrew the jet through the hole if you have just the right screwdriver. Blow the jet clear with compressed air.
   Reassembly is merely the reverse of disassembly.
    I assume you changed the plug, cleaned the air filter and changed the oil during the quiet winter spell  and this is just a bit of bad luck
  Feel free to phone me if you need any more help

[Ged]

thanks for the advice. checked the plug it looked ok. no carbon and was sort of light brown in colour at the anode. seemed to be good flow of fuel. the engine ran better today but was a b***** to start each time. was coughing and splutttering like its on sixty a day but was ok once going. i noticed that when moving the throttle lever there was a lot of play before it actually opened the throttle so guess the springs need repalcing. the air filter was clear but there was a strong smell of petrol and some oily deposits on the plate it sits on. will see what tomorrow brings will probablay have to attempt to take apart the carb i suspect

[BDCS]

http://shop.ebay.co.uk/i.html?_nkw=honda+carb+gx390&_sacat=0&_odkw=honda+carb+13hp&_osacat=0&_trksid=p3286.c0.m270.l1313

[Ged]

turns out it was a throttle link spring that had broken. its a long but thread like spring that is hidden behind the throttle govenor mechanism. just happened to notice a bit of it hanging down after removing carb. got new one £1.56 and now machine seems happy and throttle back to normal.

ged

[BDCS]

Happy days