# Honda GXV390



## .RC. (Feb 9, 2009)

We have a Honda ride on mower that is powered my a Honda GXV390 engine...

Just recently the motor has been playing up and I am scratching my head at the problem...It would run well but then stop for no reason and only starting again when it cooled down..

Just now I have changed the oil, installed a new sparkplug and tried to start it and all it will do is half kick then backfire.. To make matters worse I cannot find a service manual for it anywhere on the net for download..

Any ideas on where the problem may be or where I can get a manual???


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## bser (Jan 8, 2009)

Sounds like you may need a new coil,this is pretty typical of a coil going bad.


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## 30yearTech (Sep 14, 2006)

It does sound like the ignition module may be the problem.

You can look up some service information at the Honda Europe site:
http://www.honda-engines-eu.com/en/welcome.html

And Parts lists here: 
http://www.superxpower.com/pages/custompages/viewcustompage/952/Honda_Parts_.aspx


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## .RC. (Feb 9, 2009)

Thanks for the links everyone.....I had the mower running yesterday and it ran superbly for half an hour when it simply died....I waited a couple of hours and it went again for another ten minutes before dying....I had spark at the spark plug but it seemed very weak...I will investigate the ignition circuit..


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## 30yearTech (Sep 14, 2006)

You can't really tell by looking at spark whether it's weak or not. Check your fuel cap and make sure it's venting properly, a plugged vent in the cap can cause a vacuum in the fuel tank and fuel will stop flowing to the carburetor after the unit is run awhile. After it sits a short time air seeps into the tank and fuel will start flowing again. It's possible from your description that this may be your issue.

Best of luck....


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## .RC. (Feb 9, 2009)

30yearTech said:


> .
> 
> Best of luck....


I am going to need it...I have cleaned out the fuel tank (it was full of rubbish caused from a disintegrated fuel cap seal) Installed an after market fuel filter in the line..

Cleaned the carburettor...It seems to have spark, it would still only run for sometimes 10 minutes, sometimes half an hour...Now it won't run at all, just half splutters then lets an almighty bang as it backfires... And to top it off the valves must be done as the carburettor had oil in it..

This is the biggest POS Honda motor we have owned..It leaks oil like a sieve has always been temperamental with it's running speeds (would never idle properly) and now this....This one was obviously made on either a Friday or a Monday.. 

And to make matters worse the grass is getting out of control...


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## kennyriach (Feb 22, 2009)

*Honda's!*

Have a B&S engine that displayed the same behaviour. Spent a lot of money on a new coil / module that made little difference. The distance of the induction coils from the flywheel can make a big difference with the back firing, if it has moved back will cause that. Have replaced everything in that engine and still does same thing.


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## LowRider (Dec 23, 2008)

Question, does the engine have a third party gas tank? if so that may be a problem with air pressure not allowing fuel to flow. If so you should check and see if it possible to rig a gas cap with an adjustable screw adjustment nut or if they make them for that mower. might also want to check the fuse on the mower, i take it is electric start right?


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