Honda HS724 snowblower-high rpm

[borhani]

I noticed this posting the old forum: Honda HS624 Snowblower-high rpm, http://www.perr.com/phpBB3/viewtopic.php?f=14&t=5343

I have the same trouble with my Honda HS724 snowblower (same GX160 engine), but my particulars are a bit different.

I pulled & cleaned the carb., which was gummed up after ~10 years of only occasional use. I disassembled the bowl, float, cleaned body, but did not pull out the jets or needles. Reassembled, all seems OK, all orifices open, carb. cleaner squirts through easily.

Engine starts with one easy pull & runs OK at full throttle (I don't think too fast). But, when I pull the throttle control (single cable) to idle, the throttle plate inside the carb. throat doesn't close at all. So, it "idles" at full speed! I can (easily) close the plate with my finger---it isn't stuck, and moves freely---and when I do this the idle speed is nice, smooth, and appropriately slow.

It seems like the lighter spring that is co-axial with the governor/carb. linkage rod that attaches to the throttle plate is pulling the throttle open at idle. If I disconnect the heavier of the two governor springs (the one attached to the throttle/choke mechanism), the throttle remains open at the idle control setting. If I also disconnect the lighter spring (the one attached to the throttle plate), but leave the rigid linkage itself attached, there is nothing "pulling" the throttle open at idle. But, it doesn't close.

So what is supposed to close the throttle? When I move the cable to "idle", the throttle/choke mechanism (where all the stops are) moves properly---it is moving to the idle position---but the connection between this mechanism, through the governor to the carb. throttle plate, seems to be all "pull" and no "push" (via the springs). I don't understand how this arrangement can close the throttle (or allow it to close? Is there supposed to be a spring on the carb. itself to close the throttle plate?).

I considered that the governor could be messed up (as in the post above), but last time I ran the snowblower (last spring), it was fine, and I haven't touched anything other than the carb. But, I don't really understand this governor (in particular, that the heavy spring to the throttle/choke control, and the tie-rod & light spring to the carb. throttle butterfly plate, are attached on the same side!).

Pics attached, three at "idle" on the cable, one at full speed, one at choke.

Sorry to be so wordy, but I really don't want to lug this thing to a dealer for fixing (I don't have a truck!). Thanks so much!

Idle, spring close-up, also showing throttle/choke control mech.: https://www.dropbox.com/s/s37qhvyw48wyyiv/Idle_springcloseup.jpg
Idle, open carb. throat!: https://www.dropbox.com/s/lfimzj9nhr46hr1/Idle.jpg
Top view, idle: https://www.dropbox.com/s/jklyvszor4ui7uh/Idle_topview.jpg
Top view, choke: https://www.dropbox.com/s/9yc929g2ppqucn3/Choke_topview.jpg
Tope view, full speed: https://www.dropbox.com/s/x4ug2kab6eoozkc/FullSpeed_topview.jpg

[okie]

https://www.dropbox.com/s/s37qhvyw48wyyiv/Idle_springcloseup.jpg
[url]Idle, open carb. throat!: https://www.dropbox.com/s/lfimzj9nhr46hr1/Idle.jpg[/url]


[urlTop view, idle: https://www.dropbox.com/s/jklyvszor4ui7 ... opview.jpg][/url]

[url]Top view, choke: https://www.dropbox.com/s/9yc929g2ppquc ... opview.jpg[/url]

[url]Tope view, full speed: https://www.dropbox.com/s/x4ug2kab6eooz ... opview.jpg[/url]

Travis
I"m not allowed to work on engines.....just sweep the shop and wash parts.

[borhani]

Hoping someone is reading this besides me

I replaced the carb., and used a brand new "throttle return spring" (that rides on the linkage between carb. & governor arm). No change, still won't change rpm --- runs full blast, regardless of where I set the throttle cable. Can still adjust engine speed by manually turning the carb. throttle plate.

I removed the gas tank so I could get a close look at the governor arm. It seems *not* to be "tight" in any one position, regardless of whether the engine is stopped or is running at low or high rpm (I'm moving the carb. throttle plate manually to control the rpm). Instead, the gov. arm just seems to randomly bounce back and forth. At one end of its travel, it makes a ping-ping-ping sound, as if something is hitting it (a few pings per second). The gov. arm is tight on its rod, and the axial spring under the gov. arm, between it and the crankcase, is engaged.

Finally, as it was running, the gov. arm moved further away from the carb, now about 2 inches away, at closest approach, from the carb/gov. arm linkage. How it "slipped" I don't know (I guess I pushed it).

Is the governor broken? Is there a way to tell for sure? How big a pain is it to open up the crankcase and replace it?

(The img linker doesn't seem to work for me; here are the addresses for the governor images)
https://www.dropbox.com/s/kz998y5cixrocq2/Governor_original_position.jpg
https://www.dropbox.com/s/fbiix75bq3816pb/Governor_moved_position.jpg

Thanks

[Deere2me]

Start by adj. the gov:
Remove tank
Loosen nut on the gov arm, and rotate arm to fully open the throttle shaft. Hold in that position.
Rotate the gov shaft as far as it will go , in the same direction the arm moved to open the throttle.
Tighten nut.
Start engine and warm up.
Move throttle lever to wot and adjust stop screw for 3750-3900 rpm or so.

If it doesn't work after that, then sumpin is broke inside, or mayhaps your linkage etc is bad.

[KE4AVB]

(The img linker doesn't seem to work for me; here are the addresses for the governor images)
Thanks

It will after your third post...BTW max image size on direct viewing is 600x600 dpi.

I thought I post this a little ago I reckon I didn't; oh well probably just bump heads with Deere2me.
①. Remove the fuel tank.
②. Loosen the nut on the governor arm and move the governor
arm to fully open the throttle.
③. Rotate the governor arm shaft as far as it will go in the same
direction the governor arm moved to open the throttle.
Tighten the nut on the governor arm.
④. Start the engine and allow it to warm up to normal operating
temperature. Move the throttle lever to run the engine at the
standard maximum speed, and adjust the throttle lever limiting
screw so the throttle lever cannot be moved past that point.
Maximum engine speed: 3,900 ± 150 min-1 (rpm)
3,750 ± 150 min-1 (rpm) (DS type)

[borhani]

Thanks, will try it tomorrow. Suggestions on how to set (approximately) the high RPM without a tachometer? I could do it by "memory" of how it sounded...

[KE4AVB]

Thanks, will try it tomorrow. Suggestions on how to set (approximately) the high RPM without a tachometer? I could do it by "memory" of how it sounded...

If you haven't mess with the high speed adjustment screw then you should be fine as this sounds like the governor linkage got out adjustment or the internal governor setup failed.

Also if you need the Honda GX160 service manual drop down to download section and following the Honda link. You be able to access that section now; although, it might take another post or two before it shows up.

[borhani]

I reattached linkages/springs, after adjusting the governor rod as you described. Engine now runs OK at lowest throttle setting (estimate ~1200 rpm) --- butterfly is nearly/completely closed --- and goes to maybe double that rpm at highest throttle, even after adjusting the hi-speed stop --- and the butterfly is only ~half way open, definitely NOT against its stop on the carb. body.

The governor DOES seem to be working. If I over do the throttle, and thereby start to close the choke, I see the gov. arm seek back and forth as the engine sputters, trying to find its right place. When the engine is running at a steady (hi or lo) speed, the gov. arm is steady --- not seeking.

I'm going out to get a tachometer to put on the spark plug wire, but in the meantime...

IF the wide open throttle rpm is indeed slow (I'd estimate ~2000 or 2500), what do I adjust?

[StarTech]

These should be the adjustments. Not 100 % which is which but from your photos it appears to be right.

Yellow circled item Idle Speed and the White circled item High speed.(appears to be turn to it lowest point on the high speed)

[borhani]

Thanks, will report back with rpm values...