[arnold bright]

I have a 99 scott riding lawn mower with 17 HP Intek engine. It has been runNing just fine. I cranked it for the first time today after setting up for the winter.
It started on the first crank but had a sound as if it needed to warm up. I let it idle for a few minutes before I brought it up to full throttle. It ran fine.
When I finished mowing I disengaged the cutting blades and at full throttle the engine had a slight miss. I brought the idle down to mid range and the miss became more pronounced but still ran ok.
If I advanced the throttle it responded as normal but still had the miss. I brought it down to idle and the miss was still there. While running I removed the air filter and every once in a while at idle it would puff thru the carberator. What could be wrong?
Would it be the valves need adjusted?
I have had it since 99 but have not adjusted on the valves.
If it is in need of valve adjustment can someone tell me in detail what I need to do.
I am mechanically adept and do all my maintenance.

 

[Austen]

Welcome!

While it's possible is may need the valves adjusted, it sounds more as if the carburetor may be a little dirty, and or the gas it's running on is stale. If it did not run like this before, it is probably not valvetrain related then. I would suggest running it as it is with fresh gas for two or three more mowings and see if it clears itself out.

If it still persits to run the same after a while with the fresh fuel, then pursue cleaning the carb.

Also, something you may already do but thought I'd throw it out there anyway, if your machine has a valve on the fuel line, run the fuel out of it before winter and also inbetween times when it's not going to see a lot of use for a while. This will run the gas out of the carburetor so that there's no fuel sitting in it to potentially gum it up.

 

[bwdbrn1]

Welcome to MLMF. I would agree with Austen, if your machine has been running just fine until now, it's doubtful it needs any sort of valve adjustment. You mention you do all of your own maintenance, so I'm guessing you've checked the plugs and air filter, and can most likely attest to the idea of reading the owner's manuals and following the recommended services.

My own experience has taught me to try simpler approaches first before diving into the more complicated.

Have you tried running a bit of the product called Seafoam through it? A lot of people swear by it for keeping the fuel system cleaned up, and stabilizing today's gasolines, and many say that it improved how their machines ran after a tank or two of it. You could mix it in with the fresh gas Austen suggested as per the instructions on the label.

Sea Foam Sales Company

Let us know how things go for you.

 

[Austen]

You might try running a bit of a product called Seafoam through it.

+1, I was thinking that too.