Honda HRN216 GCV170 autochoke issues

[arekkosinski]

I had this thing since new for 5 years., Last season it's been acting up. It started with surging, then going from low to super high RPM after 8 minutes of using it.
Changed to generic carb, new plugs, new gas, new themor wax dohicky, everything clean, neat and in good shape...
Currently.......
I can start it on first pull but it will run at super low RPM, too slow to mow.
Now, after checking everything a million times, messing with governor and such. I'm convinced that auto choke is not working correctly. It seems like the thermowax pin is coming out okay to extend the spring on the "actuator" but when I do a test. Engine running and I try to move the governor arm, it seems that "actuator spring" has too much tension and not allowing the butterfly to open and allow more air in. The spring on the "actuator" is not stuck, it's seemingly acting normal. I can't imagine how it could go bad, since it's NOT STUCK. But that's what I think is the cause of the issue. I'm adding video of how it works.
Thanks in advance!!!
I'm loosing my mind.

 

[FowVay]

I don't have any comment regarding your specific issue but it's just odd timing. Two weeks ago I watched my neighbor mow his front yard with his Honda mower and it would surge with such high RPM that I was waiting for it to punch the connecting rod through the block.

I can't imagine it being safe to overspeed the blade at such incredibly high RPM. Keep us posted on what you figure out. I would suggest a new thermowax assembly from Honda just in case the aftermarket one you bought is not working as designed.

EDIT: I just remembered that my neighbor never had his Honda mower serviced to address the compression release failure on the camshaft. I don't recall them complaining about it being hard to pull-start but have you had your camshaft replaced or received a notification of a recall for the compression release?

 

[hemitom]

make sure the throttle actuator and spring are not binding I know you say they are not but double check sometimes they will bind when you put it into the hole that holds it maybe slap original carb back on as well to test.

 

[FordBroncoVWJeta]

My Honda did this since new. I have to spray out the carb with carb cleaner to fix the issue. There's a few videos on YouTube that show you how to fix this issue.

 

[50yr Street Mech]

Done a lot of re-builds on small lawn mower engines. Generic/aftermarket just don't cut it when it comes to carbs, plugs, and the thermo wax dohicky / autochoke. Honda is very finicky, just like their cars. They want what they want and that's it. I've even had problems with you're run of the mill flathead Briggs & Tecumseh aftermarket carbs. They don't idle right, start easily, bog down. I think you may have to bite the bullet and get OE parts. Make sure the plug gap is dead on too. Even air filters make a difference, believe it or not. Make sure you are using a fuel stabilizer too. Pump gas starts turning bad in 2 days !!!!! That Ethanol is a killer. Good luck. Go back with OE and you'll get you're marbles back

 

[shortyb]

Done a lot of re-builds on small lawn mower engines. Generic/aftermarket just don't cut it when it comes to carbs, plugs, and the thermo wax dohicky / autochoke. Honda is very finicky, just like their cars. They want what they want and that's it. I've even had problems with you're run of the mill flathead Briggs & Tecumseh aftermarket carbs. They don't idle right, start easily, bog down. I think you may have to bite the bullet and get OE parts. Make sure the plug gap is dead on too. Even air filters make a difference, believe it or not. Make sure you are using a fuel stabilizer too. Pump gas starts turning bad in 2 days !!!!! That Ethanol is a killer. Good luck. Go back with OE and you'll get you're marbles back

This all day long. What did you save by going generic carb vs. OE Honda? Last one I slapped on an HRN cost $21. Stuff like this it pays off in the long run to spend a few extra bucks for OE parts because they give you way fewer problems.

Back to your issue, did you adjust the governor arm correctly when you "messed" with it? It operates in conjunction with flyweights that sense load. The throttle butterfly is opened further when the governor senses higher load needs and pulls the plate open further. It may seem to have a lot of spring tension, but that is normal. As long as you can push the governor arm forward and it springs back (Mower off) it's usually good to go. Also, have you checked valve clearances? Had a neighbor's HRN doing the exact same thing after carb /thermowax etc. replacement and his clearances were off. Brought them back in spec and it runs superb. Scored a dozen nice cigars and a pretty decent bottle of bourbon for my efforts.

 

[arekkosinski]

I don't have any comment regarding your specific issue but it's just odd timing. Two weeks ago I watched my neighbor mow his front yard with his Honda mower and it would surge with such high RPM that I was waiting for it to punch the connecting rod through the block.

I can't imagine it being safe to overspeed the blade at such incredibly high RPM. Keep us posted on what you figure out. I would suggest a new thermowax assembly from Honda just in case the aftermarket one you bought is not working as designed.

EDIT: I just remembered that my neighbor never had his Honda mower serviced to address the compression release failure on the camshaft. I don't recall them complaining about it being hard to pull-start but have you had your camshaft replaced or received a notification of a recall for the compression release?

Thanks for your comments. Sadly my serial number does not fall within the recall group. I question that anyways. How certain can they be these... are affected.... and these are good. So the thermowax was HONDA OEM, and it seeminly works okay? Carb is 3rd party but since the engine runs rich, i have black smoke I might have to adjust the carb?

 

[arekkosinski]

Done a lot of re-builds on small lawn mower engines. Generic/aftermarket just don't cut it when it comes to carbs, plugs, and the thermo wax dohicky / autochoke. Honda is very finicky, just like their cars. They want what they want and that's it. I've even had problems with you're run of the mill flathead Briggs & Tecumseh aftermarket carbs. They don't idle right, start easily, bog down. I think you may have to bite the bullet and get OE parts. Make sure the plug gap is dead on too. Even air filters make a difference, believe it or not. Make sure you are using a fuel stabilizer too. Pump gas starts turning bad in 2 days !!!!! That Ethanol is a killer. Good luck. Go back with OE and you'll get you're marbles back

Good points and thank you very much. I do use stabilizer but gas is 2-3 weeks old FYI. Thermowax dohicky is OEM Honda so that's good there. Filter has been cleaned really well but it's original. I ran tests without the filter (not mowing) and it seems like it didn't make a difference.

 

[50yr Street Mech]

Never seen an adjustment on a 4 cycle lawn mower engine. They are normally factory set. 2 cycle is a whole nother ball of wax. What a pain in the --s to set them right. I got so fed up, I went to, ( dare I say it as lightning strikes me ), BATTERY powered weed wackers I'm sorry guys. Don't kick me out. ) Get a new fuel filter ( don't know how you can clean one, unless it's a mesh rock catcher in the tank) If it is a mesh rock catcher, get a paper in line filter, like a 3/8" Hipa with a magnet built inside it. They work really well. Get the OEM carb and double check all the linkage. Don;t overtighten the gaskets or you;ll crack them. Get an OE spark plug, gap to correct dimension, and get an OE air filter. Clean any rust off the magnets on the flywheel where the coil passes over them. I use a soft wire wheel on a cordless drill. That will help it start faster, ( Hotter spark )

 

[Nessism1]

Go back and clean the OEM carb. These carbs are stupid simple. Take it apart, using your phone to take photos as you go so you don't forget, and get a can of Gumout spray.

Regarding the auto choke, you can easily see the choke flapper, so as long as it's opening when warm, the choke is working correctly.

And BTW, fuel doesn't go bad in two days. That's crazy talk. Use fuel stabilizer in your garage supply can, and it will be fine for months and months.

 

[50yr Street Mech]

The process of degradation starts in 2 days. I said it " starts" to turn in 2 days. Correct amount of stabilizer will make pump gas last up to 2 years, whether in a 5 gallon jug, 1.75 gallon jug, or in the machine's tank. That applies to a 50:1 or 40:1 2 cycle mix also. They came out with True Fuel for a reason. Not that people couldn't get the mix correct. They weren't adding a stabilizer to the mix. Most people don't know about the Ethanol issue. We do, on this forum. But not you're average weekend warrior.

 

[SwampSurvivor]

I had a heck of a time with a GCV190 on my push mower.

It wouldn't close the choke when cold. Changed out the thermowax and it worked slightly better but still didn't fully work right.

So for a year, I'd just manually actuate the choke. last year, for some reason, it just started working

 

[50yr Street Mech]

Good for you !!!! You caught a break, and found a simple solution to the problem if it comes back ( hopefully not).... Actuate manually

 

[arekkosinski]

I had a heck of a time with a GCV190 on my push mower.

It wouldn't close the choke when cold. Changed out the thermowax and it worked slightly better but still didn't fully work right.

So for a year, I'd just manually actuate the choke. last year, for some reason, it just started working

I feel like if this was not-autochoke the issue would be fixed. I can't turn on/off the choke. Currently don't want to even think of switching out the auto choke to manual. This automated business is less reliable seems. Thanks for your input.

 

[SwampSurvivor]

I feel like if this was not-autochoke the issue would be fixed. I can't turn on/off the choke. Currently don't want to even think of switching out the auto choke to manual. This automated business is less reliable seems. Thanks for your input.

For what it's worth I have a pressure washer with the same exact engine but it has a regular choke.

Wonder how fesible it is to swap?