HRX217 won't run. Need help determining what is wrong

[mckeand13]

I've got an HRX217 (non auto-choke) that is giving me some fits.

I've had it for about 12 years (?) and have always maintained it well.

At the end of last season, every once in a while it would start sputtering, missing, and running terribly for 30 seconds and then start running ok again. I started off this season with it doing that again. It wasn't happening much so I didn't spend any time trying to figure it out. Recently, it got worse, and eventually wouldn't run at all.

I've been working on engines my whole life and I've had my fair share of small carbs apart for a cleaning which fixes 99% of the problems. I figure, no problem, this is an easy one.

As usual, I pulled the carb, disassembled it as much as I could, dropped everything in my ultrasonic cleaner, and then blew it all out with air. Reassembled and reinstalled. Same problem, won't run. Sort of starts, coughs, sputters a little, will barely idle. Sounds strange though as if the throttle plate is open, which I verify is, even when not running.

Naively assuming I didn't get a small passage clean, I just order up a new carb and gaskets from Honda. I'm not wasting time with this.

Put it on tonight, and same crap! Won't run, pops, backfires, sort of idles very slow, maybe.....

I verified good gas flow from petcock.
I checked choke operation, that seems perfect. Wide open choke plate anywhere in the slow to fast range, and plate is closed in the choke position.

Is there something in the governor springs that could be causing this? I get the mower hooked on branches and stuff all of the time. I never have had the springs off, but I verified the connection points against many pictures and videos so they are correct. I noticed that the short spring on the bottom of the governor arm has quite a bit of slack in it. As in, there's no preload, and the hook isn't pulling on anything at all with the throttle lever at idle position. The lower spring doesn't look stretched at all, and is attached on both ends. The long, skinny upper governor spring seems ok. It opens the throttle plate if I close it by hand. I'm not sure what else to look for on this one, but everything seems ok.

I noticed again that the throttle plate is wide open when the engine isn't running. It moves very freely with nothing connected, the linkages all move nicely, but why is it open? I don't ever remember the sound of a wide open throttle plate when starting it when it ran well.

Please offer any thoughts or suggestions. This one has me stumped and I don't like that.

Thanks.

 

[mechanic mark]

http://www.hondapartsnation.com/oemparts/c/honda_power_equipment_lawn_mower/parts

do not know which model HRX217 you have but short governor spring should not be slack, should have tension on spring when not running, try installing in another hole & give it a try.

answer to your question is yes, gap at top throttle plate looks to big, spring should be sitting in bottom of linkage, by the way which HRX217? with engine cold adjust valves also, probably not been done, just post your engine model number.

 

[mckeand13]

http://www.hondapartsnation.com/oemparts/c/honda_power_equipment_lawn_mower/parts

do not know which model HRX217 you have but short governor spring should not be slack, should have tension on spring when not running, try installing in another hole & give it a try.

My model number is: HRX217TDA

That spring looks pretty sturdy, how could that have stretched or snagged on something? I can give it a try in the second hole tonight.

Here are some pics of that lower governor spring. You can see on the left end where it connects to the throttle plate linkage, it's clearly got a lot of gap in the hook before it would apply any tension. This was with the throttle lever at idle.
Still wondering, is the throttle plate supposed to be closed when not running and throttle at idle setting?

Thanks!