[CantKeepUp]

My mom's 430 had an issue with the injector pump. I let her convince me to just let the dealer fix it. 6 Month later, I have retrieved it from the dealer and it still isn't working right. The injector pump has been rebuilt but the governor was and still is the issue. The dealer had parts on order but couldn't say when they would ever arrive because they don't make them anymore.

I just ordered a used governor (entire housing) from Ebay that I'm hoping will work. I've never torn into the injector pump and would rather not mess with the timing etc. It looks like the governor body can unbolt from the injector pump without having to remove the pump from the engine. Can anyone confirm this? Any gotchas I should avoid or be aware of? Anyone else dealt with governor issues?

 

[RussKish]

Sent you a PM

 

[nick4030]

What serial number is your 430? It would help because the early 430 is significantly different than the later models.

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[CantKeepUp]

Thank you RussKish! - that will give me some light reading to do

nick4030 - I forgot to get a pic of the Tractor Serial # (I think it is in the later years - 1990??). I'll see if I can get that (tractor is a few hours away)

Engine Model 3TNA72UJ2. Serial GH3029D018229

On the pump itself, I can read 9621-51100 and T606. There might be more - can't tell if there are other letter/digits missing or scratched out. Don't know if that is useful or not

Your question does make me wonder if I just wasted a few bucks on a used governor. If nothing else, it will give me something to play with as I try to understand how the governor works.

 

[nick4030]

What is it doing?

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[nick4030]

There's not really a whole lot to go wrong inside the governor. There's some bushings and other parts that can wear, but from what I've seen average Joe can't order those parts. They have to be ordered by an injection shop usually. If you have a good shop close by, I would give them a call. They would be able to do it no problem, and be better than a dealer. The average diesel tech isn't highly trained on injection systems. Think of it like your general family practice physician versus a cardiologist. The injection shop is the cardiologist.

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[CantKeepUp]

Originally it had two issues:
1. Every couple of times using it, it would NOT shutoff. You turn the switch, the solenoid cuts off and throws the throttle arm fully, but the rpms would just lower a wee bit as it kept running forever at low idle. You’d have to pop a load to get it to stall.
2. I was mowing tall grass with great power and then it suddenly started losing power and slowly died. If it were my 318 I would say it was running out of gas, but I had plenty of fuel. I managed to get it to run for 30 seconds at a clip as I made it back to the garage. The next day it would start and run, but was definitely lacking power. It wasn’t smoking though - just lacking power.

The dealer determined that it was an injector pump issue and had the pump sent out to a rebuild shop. I think they did the typical rebuild on the injector pump.

The engine now fires up to idle. When you move the throttle the whole way up, it sits at idle for a few seconds and then starts to slowly climb rpms up to full speed. If you toss a load on it (engage the 60inch mower), the rpms fall back to idle - eventually climbing back up. It is better when warm and much worse when very cold.

The dealer and pump shop believe that the governor is the issue(I agree). They can’t find the parts (ordered them months ago??? ). When they sent the bill (end of year accounting?) my mom said that I should just go get the tractor. I asked the dealer if it would get fixed if I left it there for a few more months and I got a blank stare and a shrug “obsolete parts”. So I took it back home.

The engine itself had a complete rebuild a few years ago - not many hours on it and I love the tractor. My 78 year old mom is mowing 5 acres of western PA hills. The tractor has (had?) great power and it is so stable - low to the ground, wide wheel base, calcite filled tires, and differential lock. That 430 is as safe as it gets on that terrain. Thus my desire to keep it going.

 

[BOSOX]

Reliance Diesel Service | Bristol VA Diesel Fuel Injection

This guy is in Virginia. Hope someone can get your injection pump squared away and the tractor running right again.


Or this one, shows he's a Yanmar service dealer in Eastern N Carolina.

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[Todd_D]

I had the governor housing off of a 430 that wasn't running right. It was scored on the inside. If I remember right, it is pretty easy to take it off and check it out.

 

[nick4030]

That does definitely sound like the governor. I would call an injection shop, they'll likely have you bring it in.

You could also check with hoye tractor, he's about the most knowledgeable yanmar guy I've come across. I would imagine that the governor was used on many yanmar engines, and the dealer probably just can't get them because they aren't an injection shop.

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[nick4030]

Any updates here?

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[CantKeepUp]

The used governor that I ordered should arrive later this week. From pics and description, I believe it should fit. The tractor is 4 hours away - hoping to make a trip next week to try it. If that fails, I'll start working on plan B.

 

[nick4030]

The used governor that I ordered should arrive later this week. From pics and description, I believe it should fit. The tractor is 4 hours away - hoping to make a trip next week to try it. If that fails, I'll start working on plan B.

Ok, post some good pictures of the internals, so we can compare. That way if this happens to someone else we can help faster.

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[CantKeepUp]

So the good news ..... installing the eBay governor has the old beast running again.

On the not so good news, I’m not sure why. As I compare the old governor vs eBay, I can’t find anything wrong with the original(they both seem the same as I play with them on the bench) I think the spring tension is slightly more in the eBay one, but not enough to account for the way this thing was running (seemed like the governor was stuck at times).

On both governor housings, I can see a wear grove on the inside that had to have been caused by the governor fly weights. The eBay housing looked a little more worse. For the fly weights to expand far enough to contact the housing, I would expect that to happen at the highest rpms - the engine had been running bad at low rpms and wouldn’t accelerate with the throttle (delayed accel). All of that really sounds like the flyweights weren’t expanding and contracting, but they look good.

I did measure the injection cam endshaft and the sleeve that rides on it (the flyweights push the sleeve against the governor) and both are well within specs. So I don’t think there is anything wrong with the flyweight assembly.

I didn’t think to try it while it was apart, but I’m wondering if it is possible to have one of the flyweights out of place (permanently stuck out) and still get the governor assembled. Just thinking that could make the governor stick???

So I’m happy to have it running again, but a little frustrated that I don’t know what the issue was. I really suspect that my old one is still good.

 

[CantKeepUp]

Sorry my phone seems to lose my paragraphs(I did not write all of that as one big paragraph) and screws up words with apostrophes

 

[nick4030]

That's interesting. Did you take any pictures?

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[CantKeepUp]

I took a few - not sure if they show much. I’ll need to look on the computer when I get home. I’ll trh to post them if they’re worthwhile

 

[CantKeepUp]

Hopefully the attachments work....

In the one pic of the governor housing, you can see the groove that is worn into the inside of the housing. I think this can only be from the flyweights (shown in the other pic/diagram).

In the flyweight diagram, the weight (part of #35) will be oriented as shown during low rpms. At that time, the sleeve (#37) will be closer to the flyweight bracket - sitting in the little shelf of the flyweight. (just ignore the nut like its not there). As the RPMs go up, the flyweights go out (rotate toward 90 degree) which causes the shelf of the flyweight to push the sleeve to the left. Pushing the sleeve to the left will push it into the governor arm - you can see the little rub plate in the center of the governor pic. As the bottom of the governor arm is pushed in, the top of the governor arm (see the second gov pic) pushes the injection pump control lever to control the injection.

For those who haven't been into a governor, I hope the pics and explanation help.

So in the case of my new and old housings, I assume the governor weights flew out too far and rubbed the groove into the housing. I'm guessing during an overspeed condition? or maybe a flyweight got out of place? Maybe the governor arm springs are too weak and allowed the sleeve to come too far and flyweight too far out?

All I know is that the engine is running great now.

FYI - The pics are of the two different governors - so the rub grove is not very prevalent in the right side pic. Ironically, the left pic with the bigger groove is the working Ebay governor.

 

[RussKish]

Did you press on any of the levers (to feel the tension on the springs for a comparison)?

 

[CantKeepUp]

The Ebay governor felt a little stronger in the springs, so I wouldn't have been surprised to see it "respond" better than the old one. I just don't think it was anywhere near enough of a difference to account for how the old one was running.

If weak springs were an issue, I wouldn't be surprised that when hitting a load at high RPM's, the springs wouldn't push back on the flyweights adequately and there would be a poor response to the load. Maybe a weak spring would allow the flyweights to be out too far and contact the housing. What I wouldn't expect from weak springs is that at low RPM, the engine would not throttle up to high RPM (It eventually did, but took 20-30 seconds. That behavior makes it sound like the governor was stuck. That's why I wonder if one flyweight was maybe out of place somehow? As I took the old governor off, I bumped the flyweights with the housing. By the time I looked at it, the sleeve was well out of place and all three flyweights were past full extension - but I believe that I caused that during removal.

So I believe that my old governor was sticking, but everything about it seemed to be in good condition. I couldn't simulate any sort of resistance/sticking/sluggishness. Aside from the slight difference in spring tension, I couldn't tell the difference between the two governors. The manual does give instructions for teardown of the governor and measurements/spec limits for wear on the governor shaft and arm. I didn't do any of that, but I feel pretty certain that there is no measurable wear.

I did see in some other threads (maybe on this forum?) where the discussion was how to get more throttle/reaction out of the governor. People were talking about shims etc. I suspect that discussion was going down the wrong road (thinking of the governor as a static thing). I suspect if you wanted to change the reaction of the governor, the springs are the key. However I also suspect that Yanmar put a good bit of research and testing into choosing the springs that they did, so opportunity to improve is limited/futile.