Engine saga continues - broken governor made engine run better?

[ktpnw]

So I have a craftsman LT1000 riding mower with a Briggs and Stratton 24HP commercial VTwin engine (not the stock engine) that I picked up for dirt cheap from a friend in non-running condition. I did all the usual (plugs, oil, carb clean x2) and got it to run ok - would still cough and bog at high throttle, black smoke at startup, took a while to start, but ran well enough to mow the lawn or drive up and down the driveway. The other day I was running it to bring my recycling out to the street in a trailer when I heard a cough/pop and all the sudden it had waaay more power. Engine revved higher, mower was way faster, and honestly felt like it was running way better. In a way, it felt like it had fixed itself. It now starts way easier, runs with more power, and no longer smokes really at all. My initial guess was that either some plugged passage in the carb finally unplugged, or a blockage in the air intake or muffler gave way and allowed the correct airflow or something like that. It truly went from running so so to running what seems like fairly well.

But... it now revs very high (or at least it seems very high to me). I'm wondering if maybe the governor broke internally. I tried adjusting the governor, and it didn't help (seems like it was adjusted correctly already, didn't change the situation). It still idles, albeit higher than before, but as soon as I give it partial throttle it revs up pretty fast. I'd say 25% throttle is "very fast" and 50-100% throttle is "very very fast" bordering on scary fast. I don't have a reference point of an engine that's working correctly, this is my first riding mower, but it seems quite high to me. When I put the engine under load (drive it around, or especially engage the mower deck) it drops back to what I'd call more normal revs.

So questions are threefold:
1) Am I correct that the governor broke? Is there an easy way to confirm this?
2) How would the governor breaking have made the mower run better?
3) Is running a mower with a broken governor unsafe, if done responsibly? This is the major question. I'm savvy enough to not over-rev the hell out of it, I can keep it at idle and rev it up as I engage the load and vice versa, and only rev to partial throttle. If I'm correct that it's overreving, I feel like I can totally reasonably control the revs using the throttle and load. I got this whole mower for $50, I don't have the time to take it apart and replace the governor myself and I don't want to spend hundreds and hundreds on having someone else do it. I don't even really care if there's a small chance of ruining the engine (I'd probably risk it). But if it's going to explode into a fireball, or shatter the flywheel, or something like that which could injure me, I obviously don't want that.

Thanks in advance for any knowledge or advice.

 

[Rivets]

Sorry, but reading your post I’ve got more questions than answers. Remember we are not standing next to you, so you must paint us a better picture of what is happening. Once we can see what is happening, we should be able to help you out. First, can you measure your RPMs? “Seems to me to be very high”, doesn’t really tell us a lot. Second, do the RPMs change when you move the throttle control? Third, do the RPMs change a lot when you put the unit under load? Again an RPMs reading would help. Fourth, how did you adjust the governor? I’ve attached a manual if you don’t have one, but it might not be the correct one because you don’t supply all engine numbers. Fifth, have you checked and adjusted the throttle linkage? Personally, from what you describe I don’t think your governor is broken, but may be out of adjustment. Please provide us with a better picture of what is happening and include all engine numbers. https://docs.google.com/open?id=0B6NaqjIxWV1yZHlwUk9CWlNwYVE

 

[ktpnw]

Sorry, but reading your post I’ve got more questions than answers. Remember we are not standing next to you, so you must paint us a better picture of what is happening. Once we can see what is happening, we should be able to help you out. First, can you measure your RPMs? “Seems to me to be very high”, doesn’t really tell us a lot. Second, do the RPMs change when you move the throttle control? Third, do the RPMs change a lot when you put the unit under load? Again an RPMs reading would help. Fourth, how did you adjust the governor? I’ve attached a manual if you don’t have one, but it might not be the correct one because you don’t supply all engine numbers. Fifth, have you checked and adjusted the throttle linkage? Personally, from what you describe I don’t think your governor is broken, but may be out of adjustment. Please provide us with a better picture of what is happening and include all engine numbers. https://docs.google.com/open?id=0B6NaqjIxWV1yZHlwUk9CWlNwYVE

Thanks for the response, and sorry for the lack of info. Here's some clarification, much appreciated:

- Can I measure RPMs: No, or at least I don't know how/don't have a tachometer
- Do the RPMs change when I move the throttle: Yes
- Do the RPMs change a lot when I put it under load: Yes
- How did I adjust the governor: Per Youtube videos and what I could find online. Put it in wide open throttle, loosened the governor shaft pinch bolt, rotated the shaft all the way the same direction as the throttle arm, retightened pinch bolt.
- Have I checked and adjusted the throttle linkage: No, didn't know I could.
Engine number is 44T977-0009-G1

Thanks again for the response and advice, I do appreciate it.

 

[Gumby83]

The RPM change with engine load is an indicator that the governor is out of adjustment, but keep in mind that governor adjustment is dependent on throttle adjustment. If you’ve had the carb off and cleaned it twice, the throttle cable could be out of adjustment.

Additionally, depending on the set up, some engines/carbs will still require you to physically hold the throttle against the stop screw during governor adjustment as even a wide open throttle won’t contact the stop screw. I don’t know for sure but I think this is done to allow a little extra power beyond WOT if needed, such as if you mow too quickly through thick grass.

First find and perform the correct procedure for adjusting the throttle; then adjust the governor.

I’m also curious about the state of the gas that was in the mower when you bought it - had the mower been sitting for more than a couple months?

 

[ktpnw]

The RPM change with engine load is an indicator that the governor is out of adjustment, but keep in mind that governor adjustment is dependent on throttle adjustment. If you’ve had the carb off and cleaned it twice, the throttle cable could be out of adjustment.

Additionally, depending on the set up, some engines/carbs will still require you to physically hold the throttle against the stop screw during governor adjustment as even a wide open throttle won’t contact the stop screw. I don’t know for sure but I think this is done to allow a little extra power beyond WOT if needed, such as if you mow too quickly through thick grass.

First find and perform the correct procedure for adjusting the throttle; then adjust the governor.

I’m also curious about the state of the gas that was in the mower when you bought it - had the mower been sitting for more than a couple months?

Excellent, thanks for the tips. I will do a throttle adjustment next and then recheck the governor adjustment. I did drain and replace the gas with fresh, so that shouldn't be the issue.

I'm also still very curious what it was that happened that caused it to all of a sudden run great (albeit at high revs). I may never know I suppose.

 

[Rivets]

RPM change when you put a load on the engine is an indication that the governor is working, if the RPMs drop when the load is applied and then come back quickly.
Thinking your engine is running to fast and trying to adjust the RPMs by ear is very tricky and I don’t recommend doing it this way. I’ve been working on engines for 50+ years and still don’t trust myself to do it, unless I’ve no choice.
By throttle adjustment, I meant adjusting the throttle control cable. To do this push the throttle control fully forward, loosen the cable clamp, push or pull the cable until the throttle butterfly is fully open, tighten the cable.

 

[ktpnw]

RPM change when you put a load on the engine is an indication that the governor is working, if the RPMs drop when the load is applied and then come back quickly.
Thinking your engine is running to fast and trying to adjust the RPMs by ear is very tricky and I don’t recommend doing it this way. I’ve been working on engines for 50+ years and still don’t trust myself to do it, unless I’ve no choice.
By throttle adjustment, I meant adjusting the throttle control cable. To do this push the throttle control fully forward, loosen the cable clamp, push or pull the cable until the throttle butterfly is fully open, tighten the cable.

Thanks much. To clarify this part " if the RPMs drop when the load is applied and then come back quickly" that is NOT the case. The RPMs drop and stay lower, until I remove the load at which point they jump way back up.

Understood on trying to guess by ear. I will look into getting a tachometer. I don't pretend to be able to guess what the RPMs are by ear, but was hoping I would be able to accurately guess what "way too high was". But maybe that's not the case.

I will do a throttle cable adjustment and see if that helps. You're absolutely right, that may be way off and could be the culprit. I have not adjusted it, and have no idea if the previous owner did either.

 

[Rivets]

Can you take some pictures of all the linkages, so we can see if you’re missing any springs and have it hooked up correctly. Resize you pics to medium or small to post.

 

[ktpnw]

Attached some photos of the linkages. I got a few angles, hopefully it's possible to see what's going on.

I adjusted the throttle cable and readjusted the governor, it changed a bit but still revs very high when not under load. There is definitely control of the revs - I am able to raise and lower the revs with the throttle, it just seems extremely high even with the throttle barely open. My options seem to be idle, very fast, and extremely fast.

Also the difference between the revs under load and not under load is huge and steady - when under load it sounds what I'd call normal, but as soon as the load is removed it revs way up (and stays high). It doesn't rev and then "adjust" as was suggested would happen if the governor was working properly. I guess if all the linkages look correct, next step is to get a tachometer to confirm it really is revving higher than expected.

Thanks again for all the help and advice.

 

[Rivets]

Stop, your first picture shows what’s wrong. The upper cable, I’m assuming the throttle control cable, should NOT be attached to the governor arm. I’m try to locate a good picture as to where to attach it. I or some else will have a pic. Is the top cable your throttle control cable and the bottom choke control?