Generac generator problem

[mikeberish]

I have a Generac Guardian Quietpact 40G RV generator with a GN220 motor with about 160 hours on it.

When I first acquired the unit the generator ran but due to what I suspected was bad gas from the previous owner the intake valve gummed up and stuck open. I replaced the valve, had the fuel tank professionally cleaned and sealed.

Now, 80 hours later I again have a stuck intake valve. Haven't gotten it apart to see if it is gummed up, but it is defiantly stuck open. Does anyone have any experience with a stuck valve on a Generac unit? I've been a mechanic for 30 years and am quite sure the repairs were done correctly.

Any suggestions? If this is chronic I'm OK with buying a new generator but would prefer to save my money if I can.

Thanks
Mike

[mikeberish]

Thanks guys. I took the valve cover off and tried prying the valve back to closed just like the first time this happened. It is stuck solid. I suspect the valve is bent which happened last time as well. I didn't try any lube on the valve as I was able to pry fairly hard and it didn't move. I don't think seafoam or oil in the gas will help since it does not run at all, wouldn't get the lube to the problem. It has fresh fuel in the tank right now. Was filled less than 2 weeks ago. Last time there was no carbon on the stem, it had gum like one would find in a carb that had been sitting. I already ordered a valve replacement kit so will go into it soon. I'll let you know if it is gummed up again.

In the future I may run some amount of Marvel Mystery oil or equivalent in the tank, but I shouldn't have to do that if the engine is engineered correctly. I'm wondering if this is a chronic problem with Generac.

[azrving]

Can you pull the valve cover? If so spray it with appropriate oil and gently apply a little force to see if it frees up. Don't pry hard on one side of the retainer as you may bend it. Try to apply even pressure on two sides. While you are in there check for a bent pushrod.

If you get it running use seafoam. Don't use old fuel. Seafoam it now and then it's probably developing carbon build up on the stem.

[colliehauler]

Did you try running Seafoam through the system?

[ScottG]

When I rode Honda motorcycles in the 80's they had a common problem of valves sticking at idle. The cure was to run some 2 stroke synthetic oil through the tank. It always cleared it right up.