[Tony Edwards]

Got a honda 390 which I am using on a temp basis

Used Thursday all day no problem

Went to use it yesterday and won't turn over. The Pull cord is so stiff it's nearly pulling my arm out its socket. Did the obvious like check fuel and clean plug etc but nothing.

Attached the hose and lance and held down the trigger ( with the water off ) but almost impossible to pull the start cable.

Seems like there is so much pressure in the machine that's why I can't pull it

Any advice much appreciated

Cheers

[Jettaway]

I keep the trigger squeezed as I fire up the engine. Im not sure if you've tried that, I couldn't quite make it out from your post.

Also why is the water off when you want the pump on?

[Tony Edwards]

Should have said I try it with both water on and off

Also keep the trigger pressed in during the whole starting process but no help doing that

[Mike Halliday]

On the pump Opposite side to the uploader is a second high pressure exit nut, unbolt it so it is just an open port so the pump has no restrictions on starting

Or take off the uploader, this will tell you if it's a build of pressure stopping it starting

[Smudger]

Have you a bypass valve ?

Mine has never been like that but it always seemed harder to pull if this was shut ( ie water going to lance ) than when open


Darran

[Tony Edwards]

Mike

There are two nuts. One looks 18-20mm the other is bigger which of of these ?

If I remove the unloaded will it still start ?

Thanks

[Jettaway]

Apologies Tony

[Mike Halliday]

The top one which has the uploader fitter on the opposite side of the pump.

The bottom bigger nut is the water  inlet.

The uploader controls water pressure, it has nothing to do with the actual starting of the engine apart from its ability to create pressure that can stop the engine turning over

[chris scott]

Take the pump/gearbox off. This will tell you if it is an engine or gearbox/pump problem.

[Tony Edwards]

Mike

Thanks for advice. Removed the unloader but the pull cord is still to hard to pull

??

[Mike Halliday]

how knowledgablr are you with the fitting of the pump?

you might have to do ask chris suggest and remove it to see if the pump has seized or its the engine

[Kenny83]

before you start taking the pump to bits or even off the shaft try taking your spark plug out and then try it, could have a flooded combustion chamber caused by a leaking carb float bowl needle or you may have tipped the engine to flood the chamber, stand back when you do it though as you may get covered in fuel  

[Tony Edwards]

Lee

Would your suggestion account for the pull cord being so hard to pull. ?

[Kenny83]

Yes, thats exactly what happens, the combustion chamber fills up with fuel and then when you go to pull it towards compression stroke the fuel cannot compress therefore creating a locking up effect... happens quite a lot, especially if the machine has been tipped over during loading on a van etc... for the sake of taking a spark plug out (4 seconds or something) it's always worth trying that first, just unscrew it and then try pulling it over 

[Kenny83]

Also check your oil level, if you unscrew the dipstick and it comes pouring out really thin then you know it got petrol past the rings, another tell tale sign of being flooded 

[Tony Edwards]

Lee

Thanks for your advice. I removed the and removed the carb chamber and drained . When I tried the start cord it was much easier to pull with no resistance

Once I put the plug back in then it was really hard do pull again.

Any more advice.

Thanks mate

[Kenny83]

Hi mate, glad it helped... however, now that you say it was hard to pull again as soon as you put the spark plug back I'm thinking 2 possible things....
1. Did you pull it fast and if so did any petrol spit out the hole where the spark plug goes? if not then you need to do that, a few times, very fast, doing this empties the combustion chamber, also leave the spark p[lug out over night to allow any excess fuel to evaporate, also did you check the oil? if so was it over filled and come running out really thin? This would indiscate the oil is full of fuel... do an oil change and top up to correct level....
2. If the above is all in order then you may need your valves setting or you may even have a sticky valve.... let me know if you think this is the cause 

[Tony Edwards]

Cheers lee

How would petrol get into the oil ?

[Kenny83]

because the machine has been tipped or the carb float needle is leaking..... it drains into your combustion chamber (under the hole where your spark plug goes) and then floods over the piston and seaps down past the piston rings into the oil 

[Ian101]

it happened to mine when I left the fuel valve open

[Kenny83]

How are you getting on with it tony?

[Tony Edwards]

Hi lee

Did what you said. With the plug out pulled the start cord lots of times and let the plug dry over night

Changed the oil as well. Put the plug in but start still really hard to pull

Not sure what else to do mate

[Smurf]

Just a thought maybe try turning over the engine with water running through the pump but no hose or lance connected just to see if it will turn over ok to eliminate a dodgy trigger on the gun. Or when you have the hose connected with a direct feed from an outside tap to the washer when you pull the trigger on the gun does water come out of the lance or not?

[Smurf]

Reason why I asked I was using a fsc then went to swap over to a lance as you do but somehow the jets on the fsc both became blocked with what looked like broken bits of o ring sticking of of both jets. Because I turned the washer off and could not release the pressure not only could I not uncouple the quick release coupling on the lenghth of pw hose but the engine could not be turned over either due to the pressure already in the system.

[Kenny83]

So its really loose and free with spark plug out? And no petrol shot out when you pulled the cord?
If so then you need to be looking at your valve settings (on the engine) maybe even a sticky valve and possibly blocked exhaust? (Long shot)
The problem is the compression in the engine is not being released out... also I believe the gx engines have an automatic decompress or in the engine somewhere, this could be at fault...
In any case I would start with the valve clearances as that's easiest, then I'd take the exhaust of if that doesn't work... After that your looking at taking the valves out and lapping / cleaning them... and that's as far as I'd go personally

[BDCS]

I'd agree the auto compressor is stuck - its on the end of the camshaft and only operates the valve when the engine spins except yours operates all the time and thats why you can't spin it over. Take it to the mower shop - if he knows what he's doing it'll only take him an hour

[paolo82]

hi tony, 
  did you find out wot the  problem was with your machine. same thing happened to my gx390 its only a year old , i took machine to seddons in birmingham as they do warranty work  they took gearbox and pump off and it worked fine, they said there was no problem with the machine.  I then booked in 2 driveways to be cleaned the following week as i almost finished  the second drive same thing happened it has not started since.  its needs to go back to a honda warranty centre . gx engines come with 3 year warranty.